1 /*
   2  * Copyright (c) 1996, 2018, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 /*
  27  * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
  28  * (C) Copyright IBM Corp. 1996 - 1998 - All Rights Reserved
  29  *
  30  *   The original version of this source code and documentation is copyrighted
  31  * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
  32  * materials are provided under terms of a License Agreement between Taligent
  33  * and Sun. This technology is protected by multiple US and International
  34  * patents. This notice and attribution to Taligent may not be removed.
  35  *   Taligent is a registered trademark of Taligent, Inc.
  36  *
  37  */
  38 
  39 package java.text;
  40 
  41 import java.io.IOException;
  42 import java.io.InvalidObjectException;
  43 import java.io.ObjectInputStream;
  44 import java.math.BigDecimal;
  45 import java.math.BigInteger;
  46 import java.math.RoundingMode;
  47 import java.text.spi.NumberFormatProvider;
  48 import java.util.ArrayList;
  49 import java.util.Currency;
  50 import java.util.Locale;
  51 import java.util.concurrent.atomic.AtomicInteger;
  52 import java.util.concurrent.atomic.AtomicLong;
  53 import sun.util.locale.provider.LocaleProviderAdapter;
  54 import sun.util.locale.provider.ResourceBundleBasedAdapter;
  55 
  56 /**
  57  * <code>DecimalFormat</code> is a concrete subclass of
  58  * <code>NumberFormat</code> that formats decimal numbers. It has a variety of
  59  * features designed to make it possible to parse and format numbers in any
  60  * locale, including support for Western, Arabic, and Indic digits.  It also
  61  * supports different kinds of numbers, including integers (123), fixed-point
  62  * numbers (123.4), scientific notation (1.23E4), percentages (12%), and
  63  * currency amounts ($123).  All of these can be localized.
  64  *
  65  * <p>To obtain a <code>NumberFormat</code> for a specific locale, including the
  66  * default locale, call one of <code>NumberFormat</code>'s factory methods, such
  67  * as <code>getInstance()</code>.  In general, do not call the
  68  * <code>DecimalFormat</code> constructors directly, since the
  69  * <code>NumberFormat</code> factory methods may return subclasses other than
  70  * <code>DecimalFormat</code>. If you need to customize the format object, do
  71  * something like this:
  72  *
  73  * <blockquote><pre>
  74  * NumberFormat f = NumberFormat.getInstance(loc);
  75  * if (f instanceof DecimalFormat) {
  76  *     ((DecimalFormat) f).setDecimalSeparatorAlwaysShown(true);
  77  * }
  78  * </pre></blockquote>
  79  *
  80  * <p>A <code>DecimalFormat</code> comprises a <em>pattern</em> and a set of
  81  * <em>symbols</em>.  The pattern may be set directly using
  82  * <code>applyPattern()</code>, or indirectly using the API methods.  The
  83  * symbols are stored in a <code>DecimalFormatSymbols</code> object.  When using
  84  * the <code>NumberFormat</code> factory methods, the pattern and symbols are
  85  * read from localized <code>ResourceBundle</code>s.
  86  *
  87  * <h3>Patterns</h3>
  88  *
  89  * <code>DecimalFormat</code> patterns have the following syntax:
  90  * <blockquote><pre>
  91  * <i>Pattern:</i>
  92  *         <i>PositivePattern</i>
  93  *         <i>PositivePattern</i> ; <i>NegativePattern</i>
  94  * <i>PositivePattern:</i>
  95  *         <i>Prefix<sub>opt</sub></i> <i>Number</i> <i>Suffix<sub>opt</sub></i>
  96  * <i>NegativePattern:</i>
  97  *         <i>Prefix<sub>opt</sub></i> <i>Number</i> <i>Suffix<sub>opt</sub></i>
  98  * <i>Prefix:</i>
  99  *         any Unicode characters except \uFFFE, \uFFFF, and special characters
 100  * <i>Suffix:</i>
 101  *         any Unicode characters except \uFFFE, \uFFFF, and special characters
 102  * <i>Number:</i>
 103  *         <i>Integer</i> <i>Exponent<sub>opt</sub></i>
 104  *         <i>Integer</i> . <i>Fraction</i> <i>Exponent<sub>opt</sub></i>
 105  * <i>Integer:</i>
 106  *         <i>MinimumInteger</i>
 107  *         #
 108  *         # <i>Integer</i>
 109  *         # , <i>Integer</i>
 110  * <i>MinimumInteger:</i>
 111  *         0
 112  *         0 <i>MinimumInteger</i>
 113  *         0 , <i>MinimumInteger</i>
 114  * <i>Fraction:</i>
 115  *         <i>MinimumFraction<sub>opt</sub></i> <i>OptionalFraction<sub>opt</sub></i>
 116  * <i>MinimumFraction:</i>
 117  *         0 <i>MinimumFraction<sub>opt</sub></i>
 118  * <i>OptionalFraction:</i>
 119  *         # <i>OptionalFraction<sub>opt</sub></i>
 120  * <i>Exponent:</i>
 121  *         E <i>MinimumExponent</i>
 122  * <i>MinimumExponent:</i>
 123  *         0 <i>MinimumExponent<sub>opt</sub></i>
 124  * </pre></blockquote>
 125  *
 126  * <p>A <code>DecimalFormat</code> pattern contains a positive and negative
 127  * subpattern, for example, <code>"#,##0.00;(#,##0.00)"</code>.  Each
 128  * subpattern has a prefix, numeric part, and suffix. The negative subpattern
 129  * is optional; if absent, then the positive subpattern prefixed with the
 130  * localized minus sign (<code>'-'</code> in most locales) is used as the
 131  * negative subpattern. That is, <code>"0.00"</code> alone is equivalent to
 132  * <code>"0.00;-0.00"</code>.  If there is an explicit negative subpattern, it
 133  * serves only to specify the negative prefix and suffix; the number of digits,
 134  * minimal digits, and other characteristics are all the same as the positive
 135  * pattern. That means that <code>"#,##0.0#;(#)"</code> produces precisely
 136  * the same behavior as <code>"#,##0.0#;(#,##0.0#)"</code>.
 137  *
 138  * <p>The prefixes, suffixes, and various symbols used for infinity, digits,
 139  * thousands separators, decimal separators, etc. may be set to arbitrary
 140  * values, and they will appear properly during formatting.  However, care must
 141  * be taken that the symbols and strings do not conflict, or parsing will be
 142  * unreliable.  For example, either the positive and negative prefixes or the
 143  * suffixes must be distinct for <code>DecimalFormat.parse()</code> to be able
 144  * to distinguish positive from negative values.  (If they are identical, then
 145  * <code>DecimalFormat</code> will behave as if no negative subpattern was
 146  * specified.)  Another example is that the decimal separator and thousands
 147  * separator should be distinct characters, or parsing will be impossible.
 148  *
 149  * <p>The grouping separator is commonly used for thousands, but in some
 150  * countries it separates ten-thousands. The grouping size is a constant number
 151  * of digits between the grouping characters, such as 3 for 100,000,000 or 4 for
 152  * 1,0000,0000.  If you supply a pattern with multiple grouping characters, the
 153  * interval between the last one and the end of the integer is the one that is
 154  * used. So <code>"#,##,###,####"</code> == <code>"######,####"</code> ==
 155  * <code>"##,####,####"</code>.
 156  *
 157  * <h4><a id="special_pattern_character">Special Pattern Characters</a></h4>
 158  *
 159  * <p>Many characters in a pattern are taken literally; they are matched during
 160  * parsing and output unchanged during formatting.  Special characters, on the
 161  * other hand, stand for other characters, strings, or classes of characters.
 162  * They must be quoted, unless noted otherwise, if they are to appear in the
 163  * prefix or suffix as literals.
 164  *
 165  * <p>The characters listed here are used in non-localized patterns.  Localized
 166  * patterns use the corresponding characters taken from this formatter's
 167  * <code>DecimalFormatSymbols</code> object instead, and these characters lose
 168  * their special status.  Two exceptions are the currency sign and quote, which
 169  * are not localized.
 170  *
 171  * <blockquote>
 172  * <table class="striped">
 173  * <caption style="display:none">Chart showing symbol, location, localized, and meaning.</caption>
 174  * <thead>
 175  *     <tr>
 176  *          <th scope="col" style="text-align:left">Symbol
 177  *          <th scope="col" style="text-align:left">Location
 178  *          <th scope="col" style="text-align:left">Localized?
 179  *          <th scope="col" style="text-align:left">Meaning
 180  * </thead>
 181  * <tbody>
 182  *     <tr style="vertical-align:top">
 183  *          <th scope="row"><code>0</code>
 184  *          <td>Number
 185  *          <td>Yes
 186  *          <td>Digit
 187  *     <tr style="vertical-align: top">
 188  *          <th scope="row"><code>#</code>
 189  *          <td>Number
 190  *          <td>Yes
 191  *          <td>Digit, zero shows as absent
 192  *     <tr style="vertical-align:top">
 193  *          <th scope="row"><code>.</code>
 194  *          <td>Number
 195  *          <td>Yes
 196  *          <td>Decimal separator or monetary decimal separator
 197  *     <tr style="vertical-align: top">
 198  *          <th scope="row"><code>-</code>
 199  *          <td>Number
 200  *          <td>Yes
 201  *          <td>Minus sign
 202  *     <tr style="vertical-align:top">
 203  *          <th scope="row"><code>,</code>
 204  *          <td>Number
 205  *          <td>Yes
 206  *          <td>Grouping separator
 207  *     <tr style="vertical-align: top">
 208  *          <th scope="row"><code>E</code>
 209  *          <td>Number
 210  *          <td>Yes
 211  *          <td>Separates mantissa and exponent in scientific notation.
 212  *              <em>Need not be quoted in prefix or suffix.</em>
 213  *     <tr style="vertical-align:top">
 214  *          <th scope="row"><code>;</code>
 215  *          <td>Subpattern boundary
 216  *          <td>Yes
 217  *          <td>Separates positive and negative subpatterns
 218  *     <tr style="vertical-align: top">
 219  *          <th scope="row"><code>%</code>
 220  *          <td>Prefix or suffix
 221  *          <td>Yes
 222  *          <td>Multiply by 100 and show as percentage
 223  *     <tr style="vertical-align:top">
 224  *          <th scope="row"><code>\u2030</code>
 225  *          <td>Prefix or suffix
 226  *          <td>Yes
 227  *          <td>Multiply by 1000 and show as per mille value
 228  *     <tr style="vertical-align: top">
 229  *          <th scope="row"><code>¤</code> (<code>\u00A4</code>)
 230  *          <td>Prefix or suffix
 231  *          <td>No
 232  *          <td>Currency sign, replaced by currency symbol.  If
 233  *              doubled, replaced by international currency symbol.
 234  *              If present in a pattern, the monetary decimal separator
 235  *              is used instead of the decimal separator.
 236  *     <tr style="vertical-align:top">
 237  *          <th scope="row"><code>'</code>
 238  *          <td>Prefix or suffix
 239  *          <td>No
 240  *          <td>Used to quote special characters in a prefix or suffix,
 241  *              for example, <code>"'#'#"</code> formats 123 to
 242  *              <code>"#123"</code>.  To create a single quote
 243  *              itself, use two in a row: <code>"# o''clock"</code>.
 244  * </tbody>
 245  * </table>
 246  * </blockquote>
 247  *
 248  * <h4>Scientific Notation</h4>
 249  *
 250  * <p>Numbers in scientific notation are expressed as the product of a mantissa
 251  * and a power of ten, for example, 1234 can be expressed as 1.234 x 10^3.  The
 252  * mantissa is often in the range 1.0 &le; x {@literal <} 10.0, but it need not
 253  * be.
 254  * <code>DecimalFormat</code> can be instructed to format and parse scientific
 255  * notation <em>only via a pattern</em>; there is currently no factory method
 256  * that creates a scientific notation format.  In a pattern, the exponent
 257  * character immediately followed by one or more digit characters indicates
 258  * scientific notation.  Example: <code>"0.###E0"</code> formats the number
 259  * 1234 as <code>"1.234E3"</code>.
 260  *
 261  * <ul>
 262  * <li>The number of digit characters after the exponent character gives the
 263  * minimum exponent digit count.  There is no maximum.  Negative exponents are
 264  * formatted using the localized minus sign, <em>not</em> the prefix and suffix
 265  * from the pattern.  This allows patterns such as <code>"0.###E0 m/s"</code>.
 266  *
 267  * <li>The minimum and maximum number of integer digits are interpreted
 268  * together:
 269  *
 270  * <ul>
 271  * <li>If the maximum number of integer digits is greater than their minimum number
 272  * and greater than 1, it forces the exponent to be a multiple of the maximum
 273  * number of integer digits, and the minimum number of integer digits to be
 274  * interpreted as 1.  The most common use of this is to generate
 275  * <em>engineering notation</em>, in which the exponent is a multiple of three,
 276  * e.g., <code>"##0.#####E0"</code>. Using this pattern, the number 12345
 277  * formats to <code>"12.345E3"</code>, and 123456 formats to
 278  * <code>"123.456E3"</code>.
 279  *
 280  * <li>Otherwise, the minimum number of integer digits is achieved by adjusting the
 281  * exponent.  Example: 0.00123 formatted with <code>"00.###E0"</code> yields
 282  * <code>"12.3E-4"</code>.
 283  * </ul>
 284  *
 285  * <li>The number of significant digits in the mantissa is the sum of the
 286  * <em>minimum integer</em> and <em>maximum fraction</em> digits, and is
 287  * unaffected by the maximum integer digits.  For example, 12345 formatted with
 288  * <code>"##0.##E0"</code> is <code>"12.3E3"</code>. To show all digits, set
 289  * the significant digits count to zero.  The number of significant digits
 290  * does not affect parsing.
 291  *
 292  * <li>Exponential patterns may not contain grouping separators.
 293  * </ul>
 294  *
 295  * <h4>Rounding</h4>
 296  *
 297  * <code>DecimalFormat</code> provides rounding modes defined in
 298  * {@link java.math.RoundingMode} for formatting.  By default, it uses
 299  * {@link java.math.RoundingMode#HALF_EVEN RoundingMode.HALF_EVEN}.
 300  *
 301  * <h4>Digits</h4>
 302  *
 303  * For formatting, <code>DecimalFormat</code> uses the ten consecutive
 304  * characters starting with the localized zero digit defined in the
 305  * <code>DecimalFormatSymbols</code> object as digits. For parsing, these
 306  * digits as well as all Unicode decimal digits, as defined by
 307  * {@link Character#digit Character.digit}, are recognized.
 308  *
 309  * <h4>Special Values</h4>
 310  *
 311  * <p><code>NaN</code> is formatted as a string, which typically has a single character
 312  * <code>\uFFFD</code>.  This string is determined by the
 313  * <code>DecimalFormatSymbols</code> object.  This is the only value for which
 314  * the prefixes and suffixes are not used.
 315  *
 316  * <p>Infinity is formatted as a string, which typically has a single character
 317  * <code>\u221E</code>, with the positive or negative prefixes and suffixes
 318  * applied.  The infinity string is determined by the
 319  * <code>DecimalFormatSymbols</code> object.
 320  *
 321  * <p>Negative zero (<code>"-0"</code>) parses to
 322  * <ul>
 323  * <li><code>BigDecimal(0)</code> if <code>isParseBigDecimal()</code> is
 324  * true,
 325  * <li><code>Long(0)</code> if <code>isParseBigDecimal()</code> is false
 326  *     and <code>isParseIntegerOnly()</code> is true,
 327  * <li><code>Double(-0.0)</code> if both <code>isParseBigDecimal()</code>
 328  * and <code>isParseIntegerOnly()</code> are false.
 329  * </ul>
 330  *
 331  * <h4><a id="synchronization">Synchronization</a></h4>
 332  *
 333  * <p>
 334  * Decimal formats are generally not synchronized.
 335  * It is recommended to create separate format instances for each thread.
 336  * If multiple threads access a format concurrently, it must be synchronized
 337  * externally.
 338  *
 339  * <h4>Example</h4>
 340  *
 341  * <blockquote><pre>{@code
 342  * <strong>// Print out a number using the localized number, integer, currency,
 343  * // and percent format for each locale</strong>
 344  * Locale[] locales = NumberFormat.getAvailableLocales();
 345  * double myNumber = -1234.56;
 346  * NumberFormat form;
 347  * for (int j = 0; j < 4; ++j) {
 348  *     System.out.println("FORMAT");
 349  *     for (int i = 0; i < locales.length; ++i) {
 350  *         if (locales[i].getCountry().length() == 0) {
 351  *            continue; // Skip language-only locales
 352  *         }
 353  *         System.out.print(locales[i].getDisplayName());
 354  *         switch (j) {
 355  *         case 0:
 356  *             form = NumberFormat.getInstance(locales[i]); break;
 357  *         case 1:
 358  *             form = NumberFormat.getIntegerInstance(locales[i]); break;
 359  *         case 2:
 360  *             form = NumberFormat.getCurrencyInstance(locales[i]); break;
 361  *         default:
 362  *             form = NumberFormat.getPercentInstance(locales[i]); break;
 363  *         }
 364  *         if (form instanceof DecimalFormat) {
 365  *             System.out.print(": " + ((DecimalFormat) form).toPattern());
 366  *         }
 367  *         System.out.print(" -> " + form.format(myNumber));
 368  *         try {
 369  *             System.out.println(" -> " + form.parse(form.format(myNumber)));
 370  *         } catch (ParseException e) {}
 371  *     }
 372  * }
 373  * }</pre></blockquote>
 374  *
 375  * @see          <a href="http://docs.oracle.com/javase/tutorial/i18n/format/decimalFormat.html">Java Tutorial</a>
 376  * @see          NumberFormat
 377  * @see          DecimalFormatSymbols
 378  * @see          ParsePosition
 379  * @author       Mark Davis
 380  * @author       Alan Liu
 381  * @since 1.1
 382  */
 383 public class DecimalFormat extends NumberFormat {
 384 
 385     /**
 386      * Creates a DecimalFormat using the default pattern and symbols
 387      * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
 388      * This is a convenient way to obtain a
 389      * DecimalFormat when internationalization is not the main concern.
 390      * <p>
 391      * To obtain standard formats for a given locale, use the factory methods
 392      * on NumberFormat such as getNumberInstance. These factories will
 393      * return the most appropriate sub-class of NumberFormat for a given
 394      * locale.
 395      *
 396      * @see java.text.NumberFormat#getInstance
 397      * @see java.text.NumberFormat#getNumberInstance
 398      * @see java.text.NumberFormat#getCurrencyInstance
 399      * @see java.text.NumberFormat#getPercentInstance
 400      */
 401     public DecimalFormat() {
 402         // Get the pattern for the default locale.
 403         Locale def = Locale.getDefault(Locale.Category.FORMAT);
 404         LocaleProviderAdapter adapter = LocaleProviderAdapter.getAdapter(NumberFormatProvider.class, def);
 405         if (!(adapter instanceof ResourceBundleBasedAdapter)) {
 406             adapter = LocaleProviderAdapter.getResourceBundleBased();
 407         }
 408         String[] all = adapter.getLocaleResources(def).getNumberPatterns();
 409 
 410         // Always applyPattern after the symbols are set
 411         this.symbols = DecimalFormatSymbols.getInstance(def);
 412         applyPattern(all[0], false);
 413     }
 414 
 415 
 416     /**
 417      * Creates a DecimalFormat using the given pattern and the symbols
 418      * for the default {@link java.util.Locale.Category#FORMAT FORMAT} locale.
 419      * This is a convenient way to obtain a
 420      * DecimalFormat when internationalization is not the main concern.
 421      * <p>
 422      * To obtain standard formats for a given locale, use the factory methods
 423      * on NumberFormat such as getNumberInstance. These factories will
 424      * return the most appropriate sub-class of NumberFormat for a given
 425      * locale.
 426      *
 427      * @param pattern a non-localized pattern string.
 428      * @exception NullPointerException if <code>pattern</code> is null
 429      * @exception IllegalArgumentException if the given pattern is invalid.
 430      * @see java.text.NumberFormat#getInstance
 431      * @see java.text.NumberFormat#getNumberInstance
 432      * @see java.text.NumberFormat#getCurrencyInstance
 433      * @see java.text.NumberFormat#getPercentInstance
 434      */
 435     public DecimalFormat(String pattern) {
 436         // Always applyPattern after the symbols are set
 437         this.symbols = DecimalFormatSymbols.getInstance(Locale.getDefault(Locale.Category.FORMAT));
 438         applyPattern(pattern, false);
 439     }
 440 
 441 
 442     /**
 443      * Creates a DecimalFormat using the given pattern and symbols.
 444      * Use this constructor when you need to completely customize the
 445      * behavior of the format.
 446      * <p>
 447      * To obtain standard formats for a given
 448      * locale, use the factory methods on NumberFormat such as
 449      * getInstance or getCurrencyInstance. If you need only minor adjustments
 450      * to a standard format, you can modify the format returned by
 451      * a NumberFormat factory method.
 452      *
 453      * @param pattern a non-localized pattern string
 454      * @param symbols the set of symbols to be used
 455      * @exception NullPointerException if any of the given arguments is null
 456      * @exception IllegalArgumentException if the given pattern is invalid
 457      * @see java.text.NumberFormat#getInstance
 458      * @see java.text.NumberFormat#getNumberInstance
 459      * @see java.text.NumberFormat#getCurrencyInstance
 460      * @see java.text.NumberFormat#getPercentInstance
 461      * @see java.text.DecimalFormatSymbols
 462      */
 463     public DecimalFormat (String pattern, DecimalFormatSymbols symbols) {
 464         // Always applyPattern after the symbols are set
 465         this.symbols = (DecimalFormatSymbols)symbols.clone();
 466         applyPattern(pattern, false);
 467     }
 468 
 469 
 470     // Overrides
 471     /**
 472      * Formats a number and appends the resulting text to the given string
 473      * buffer.
 474      * The number can be of any subclass of {@link java.lang.Number}.
 475      * <p>
 476      * This implementation uses the maximum precision permitted.
 477      * @param number     the number to format
 478      * @param toAppendTo the <code>StringBuffer</code> to which the formatted
 479      *                   text is to be appended
 480      * @param pos        keeps track on the position of the field within the
 481      *                   returned string. For example, for formatting a number
 482      *                   {@code 1234567.89} in {@code Locale.US} locale,
 483      *                   if the given {@code fieldPosition} is
 484      *                   {@link NumberFormat#INTEGER_FIELD}, the begin index
 485      *                   and end index of {@code fieldPosition} will be set
 486      *                   to 0 and 9, respectively for the output string
 487      *                   {@code 1,234,567.89}.
 488      * @return           the value passed in as <code>toAppendTo</code>
 489      * @exception        IllegalArgumentException if <code>number</code> is
 490      *                   null or not an instance of <code>Number</code>.
 491      * @exception        NullPointerException if <code>toAppendTo</code> or
 492      *                   <code>pos</code> is null
 493      * @exception        ArithmeticException if rounding is needed with rounding
 494      *                   mode being set to RoundingMode.UNNECESSARY
 495      * @see              java.text.FieldPosition
 496      */
 497     @Override
 498     public final StringBuffer format(Object number,
 499                                      StringBuffer toAppendTo,
 500                                      FieldPosition pos) {
 501         if (number instanceof Long || number instanceof Integer ||
 502                    number instanceof Short || number instanceof Byte ||
 503                    number instanceof AtomicInteger ||
 504                    number instanceof AtomicLong ||
 505                    (number instanceof BigInteger &&
 506                     ((BigInteger)number).bitLength () < 64)) {
 507             return format(((Number)number).longValue(), toAppendTo, pos);
 508         } else if (number instanceof BigDecimal) {
 509             return format((BigDecimal)number, toAppendTo, pos);
 510         } else if (number instanceof BigInteger) {
 511             return format((BigInteger)number, toAppendTo, pos);
 512         } else if (number instanceof Number) {
 513             return format(((Number)number).doubleValue(), toAppendTo, pos);
 514         } else {
 515             throw new IllegalArgumentException("Cannot format given Object as a Number");
 516         }
 517     }
 518 
 519     /**
 520      * Formats a double to produce a string.
 521      * @param number    The double to format
 522      * @param result    where the text is to be appended
 523      * @param fieldPosition    keeps track on the position of the field within
 524      *                         the returned string. For example, for formatting
 525      *                         a number {@code 1234567.89} in {@code Locale.US}
 526      *                         locale, if the given {@code fieldPosition} is
 527      *                         {@link NumberFormat#INTEGER_FIELD}, the begin index
 528      *                         and end index of {@code fieldPosition} will be set
 529      *                         to 0 and 9, respectively for the output string
 530      *                         {@code 1,234,567.89}.
 531      * @exception NullPointerException if {@code result} or
 532      *            {@code fieldPosition} is {@code null}
 533      * @exception ArithmeticException if rounding is needed with rounding
 534      *            mode being set to RoundingMode.UNNECESSARY
 535      * @return The formatted number string
 536      * @see java.text.FieldPosition
 537      */
 538     @Override
 539     public StringBuffer format(double number, StringBuffer result,
 540                                FieldPosition fieldPosition) {
 541         // If fieldPosition is a DontCareFieldPosition instance we can
 542         // try to go to fast-path code.
 543         boolean tryFastPath = false;
 544         if (fieldPosition == DontCareFieldPosition.INSTANCE)
 545             tryFastPath = true;
 546         else {
 547             fieldPosition.setBeginIndex(0);
 548             fieldPosition.setEndIndex(0);
 549         }
 550 
 551         if (tryFastPath) {
 552             String tempResult = fastFormat(number);
 553             if (tempResult != null) {
 554                 result.append(tempResult);
 555                 return result;
 556             }
 557         }
 558 
 559         // if fast-path could not work, we fallback to standard code.
 560         return format(number, result, fieldPosition.getFieldDelegate());
 561     }
 562 
 563     /**
 564      * Formats a double to produce a string.
 565      * @param number    The double to format
 566      * @param result    where the text is to be appended
 567      * @param delegate notified of locations of sub fields
 568      * @exception       ArithmeticException if rounding is needed with rounding
 569      *                  mode being set to RoundingMode.UNNECESSARY
 570      * @return The formatted number string
 571      */
 572     StringBuffer format(double number, StringBuffer result,
 573                                 FieldDelegate delegate) {
 574 
 575         boolean nanOrInfinity = handleNaN(number, result, delegate);
 576         if (nanOrInfinity) {
 577             return result;
 578         }
 579 
 580         /* Detecting whether a double is negative is easy with the exception of
 581          * the value -0.0.  This is a double which has a zero mantissa (and
 582          * exponent), but a negative sign bit.  It is semantically distinct from
 583          * a zero with a positive sign bit, and this distinction is important
 584          * to certain kinds of computations.  However, it's a little tricky to
 585          * detect, since (-0.0 == 0.0) and !(-0.0 < 0.0).  How then, you may
 586          * ask, does it behave distinctly from +0.0?  Well, 1/(-0.0) ==
 587          * -Infinity.  Proper detection of -0.0 is needed to deal with the
 588          * issues raised by bugs 4106658, 4106667, and 4147706.  Liu 7/6/98.
 589          */
 590         boolean isNegative = ((number < 0.0) || (number == 0.0 && 1/number < 0.0)) ^ (multiplier < 0);
 591 
 592         if (multiplier != 1) {
 593             number *= multiplier;
 594         }
 595 
 596         nanOrInfinity = handleInfinity(number, result, delegate, isNegative);
 597         if (nanOrInfinity) {
 598             return result;
 599         }
 600 
 601         if (isNegative) {
 602             number = -number;
 603         }
 604 
 605         // at this point we are guaranteed a nonnegative finite number.
 606         assert (number >= 0 && !Double.isInfinite(number));
 607         return doubleSubformat(number, result, delegate, isNegative);
 608     }
 609 
 610     /**
 611      * Checks if the given {@code number} is {@code Double.NaN}. if yes;
 612      * appends the NaN symbol to the result string. The NaN string is
 613      * determined by the DecimalFormatSymbols object.
 614      * @param number the double number to format
 615      * @param result where the text is to be appended
 616      * @param delegate notified of locations of sub fields
 617      * @return true, if number is a NaN; false otherwise
 618      */
 619     boolean handleNaN(double number, StringBuffer result,
 620             FieldDelegate delegate) {
 621         if (Double.isNaN(number)
 622                 || (Double.isInfinite(number) && multiplier == 0)) {
 623             int iFieldStart = result.length();
 624             result.append(symbols.getNaN());
 625             delegate.formatted(INTEGER_FIELD, Field.INTEGER, Field.INTEGER,
 626                     iFieldStart, result.length(), result);
 627             return true;
 628         }
 629         return false;
 630     }
 631 
 632     /**
 633      * Checks if the given {@code number} is {@code Double.NEGATIVE_INFINITY}
 634      * or {@code Double.POSITIVE_INFINITY}. if yes;
 635      * appends the infinity string to the result string. The infinity string is
 636      * determined by the DecimalFormatSymbols object.
 637      * @param number the double number to format
 638      * @param result where the text is to be appended
 639      * @param delegate notified of locations of sub fields
 640      * @param isNegative whether the given {@code number} is negative
 641      * @return true, if number is a {@code Double.NEGATIVE_INFINITY} or
 642      *         {@code Double.POSITIVE_INFINITY}; false otherwise
 643      */
 644     boolean handleInfinity(double number, StringBuffer result,
 645             FieldDelegate delegate, boolean isNegative) {
 646         if (Double.isInfinite(number)) {
 647             if (isNegative) {
 648                 append(result, negativePrefix, delegate,
 649                        getNegativePrefixFieldPositions(), Field.SIGN);
 650             } else {
 651                 append(result, positivePrefix, delegate,
 652                        getPositivePrefixFieldPositions(), Field.SIGN);
 653             }
 654 
 655             int iFieldStart = result.length();
 656             result.append(symbols.getInfinity());
 657             delegate.formatted(INTEGER_FIELD, Field.INTEGER, Field.INTEGER,
 658                                iFieldStart, result.length(), result);
 659 
 660             if (isNegative) {
 661                 append(result, negativeSuffix, delegate,
 662                        getNegativeSuffixFieldPositions(), Field.SIGN);
 663             } else {
 664                 append(result, positiveSuffix, delegate,
 665                        getPositiveSuffixFieldPositions(), Field.SIGN);
 666             }
 667 
 668             return true;
 669         }
 670         return false;
 671     }
 672 
 673     StringBuffer doubleSubformat(double number, StringBuffer result,
 674             FieldDelegate delegate, boolean isNegative) {
 675         synchronized (digitList) {
 676             int maxIntDigits = super.getMaximumIntegerDigits();
 677             int minIntDigits = super.getMinimumIntegerDigits();
 678             int maxFraDigits = super.getMaximumFractionDigits();
 679             int minFraDigits = super.getMinimumFractionDigits();
 680 
 681             digitList.set(isNegative, number, useExponentialNotation
 682                     ? maxIntDigits + maxFraDigits : maxFraDigits,
 683                     !useExponentialNotation);
 684             return subformat(result, delegate, isNegative, false,
 685                     maxIntDigits, minIntDigits, maxFraDigits, minFraDigits);
 686         }
 687     }
 688 
 689     /**
 690      * Format a long to produce a string.
 691      * @param number    The long to format
 692      * @param result    where the text is to be appended
 693      * @param fieldPosition    keeps track on the position of the field within
 694      *                         the returned string. For example, for formatting
 695      *                         a number {@code 123456789} in {@code Locale.US}
 696      *                         locale, if the given {@code fieldPosition} is
 697      *                         {@link NumberFormat#INTEGER_FIELD}, the begin index
 698      *                         and end index of {@code fieldPosition} will be set
 699      *                         to 0 and 11, respectively for the output string
 700      *                         {@code 123,456,789}.
 701      * @exception       NullPointerException if {@code result} or
 702      *                  {@code fieldPosition} is {@code null}
 703      * @exception       ArithmeticException if rounding is needed with rounding
 704      *                  mode being set to RoundingMode.UNNECESSARY
 705      * @return The formatted number string
 706      * @see java.text.FieldPosition
 707      */
 708     @Override
 709     public StringBuffer format(long number, StringBuffer result,
 710                                FieldPosition fieldPosition) {
 711         fieldPosition.setBeginIndex(0);
 712         fieldPosition.setEndIndex(0);
 713 
 714         return format(number, result, fieldPosition.getFieldDelegate());
 715     }
 716 
 717     /**
 718      * Format a long to produce a string.
 719      * @param number    The long to format
 720      * @param result    where the text is to be appended
 721      * @param delegate notified of locations of sub fields
 722      * @return The formatted number string
 723      * @exception        ArithmeticException if rounding is needed with rounding
 724      *                   mode being set to RoundingMode.UNNECESSARY
 725      * @see java.text.FieldPosition
 726      */
 727     StringBuffer format(long number, StringBuffer result,
 728                                FieldDelegate delegate) {
 729         boolean isNegative = (number < 0);
 730         if (isNegative) {
 731             number = -number;
 732         }
 733 
 734         // In general, long values always represent real finite numbers, so
 735         // we don't have to check for +/- Infinity or NaN.  However, there
 736         // is one case we have to be careful of:  The multiplier can push
 737         // a number near MIN_VALUE or MAX_VALUE outside the legal range.  We
 738         // check for this before multiplying, and if it happens we use
 739         // BigInteger instead.
 740         boolean useBigInteger = false;
 741         if (number < 0) { // This can only happen if number == Long.MIN_VALUE.
 742             if (multiplier != 0) {
 743                 useBigInteger = true;
 744             }
 745         } else if (multiplier != 1 && multiplier != 0) {
 746             long cutoff = Long.MAX_VALUE / multiplier;
 747             if (cutoff < 0) {
 748                 cutoff = -cutoff;
 749             }
 750             useBigInteger = (number > cutoff);
 751         }
 752 
 753         if (useBigInteger) {
 754             if (isNegative) {
 755                 number = -number;
 756             }
 757             BigInteger bigIntegerValue = BigInteger.valueOf(number);
 758             return format(bigIntegerValue, result, delegate, true);
 759         }
 760 
 761         number *= multiplier;
 762         if (number == 0) {
 763             isNegative = false;
 764         } else {
 765             if (multiplier < 0) {
 766                 number = -number;
 767                 isNegative = !isNegative;
 768             }
 769         }
 770 
 771         synchronized(digitList) {
 772             int maxIntDigits = super.getMaximumIntegerDigits();
 773             int minIntDigits = super.getMinimumIntegerDigits();
 774             int maxFraDigits = super.getMaximumFractionDigits();
 775             int minFraDigits = super.getMinimumFractionDigits();
 776 
 777             digitList.set(isNegative, number,
 778                      useExponentialNotation ? maxIntDigits + maxFraDigits : 0);
 779 
 780             return subformat(result, delegate, isNegative, true,
 781                        maxIntDigits, minIntDigits, maxFraDigits, minFraDigits);
 782         }
 783     }
 784 
 785     /**
 786      * Formats a BigDecimal to produce a string.
 787      * @param number    The BigDecimal to format
 788      * @param result    where the text is to be appended
 789      * @param fieldPosition    keeps track on the position of the field within
 790      *                         the returned string. For example, for formatting
 791      *                         a number {@code 1234567.89} in {@code Locale.US}
 792      *                         locale, if the given {@code fieldPosition} is
 793      *                         {@link NumberFormat#INTEGER_FIELD}, the begin index
 794      *                         and end index of {@code fieldPosition} will be set
 795      *                         to 0 and 9, respectively for the output string
 796      *                         {@code 1,234,567.89}.
 797      * @return The formatted number string
 798      * @exception        ArithmeticException if rounding is needed with rounding
 799      *                   mode being set to RoundingMode.UNNECESSARY
 800      * @see java.text.FieldPosition
 801      */
 802     private StringBuffer format(BigDecimal number, StringBuffer result,
 803                                 FieldPosition fieldPosition) {
 804         fieldPosition.setBeginIndex(0);
 805         fieldPosition.setEndIndex(0);
 806         return format(number, result, fieldPosition.getFieldDelegate());
 807     }
 808 
 809     /**
 810      * Formats a BigDecimal to produce a string.
 811      * @param number    The BigDecimal to format
 812      * @param result    where the text is to be appended
 813      * @param delegate notified of locations of sub fields
 814      * @exception        ArithmeticException if rounding is needed with rounding
 815      *                   mode being set to RoundingMode.UNNECESSARY
 816      * @return The formatted number string
 817      */
 818     StringBuffer format(BigDecimal number, StringBuffer result,
 819                                 FieldDelegate delegate) {
 820         if (multiplier != 1) {
 821             number = number.multiply(getBigDecimalMultiplier());
 822         }
 823         boolean isNegative = number.signum() == -1;
 824         if (isNegative) {
 825             number = number.negate();
 826         }
 827 
 828         synchronized(digitList) {
 829             int maxIntDigits = getMaximumIntegerDigits();
 830             int minIntDigits = getMinimumIntegerDigits();
 831             int maxFraDigits = getMaximumFractionDigits();
 832             int minFraDigits = getMinimumFractionDigits();
 833             int maximumDigits = maxIntDigits + maxFraDigits;
 834 
 835             digitList.set(isNegative, number, useExponentialNotation ?
 836                 ((maximumDigits < 0) ? Integer.MAX_VALUE : maximumDigits) :
 837                 maxFraDigits, !useExponentialNotation);
 838 
 839             return subformat(result, delegate, isNegative, false,
 840                 maxIntDigits, minIntDigits, maxFraDigits, minFraDigits);
 841         }
 842     }
 843 
 844     /**
 845      * Format a BigInteger to produce a string.
 846      * @param number    The BigInteger to format
 847      * @param result    where the text is to be appended
 848      * @param fieldPosition    keeps track on the position of the field within
 849      *                         the returned string. For example, for formatting
 850      *                         a number {@code 123456789} in {@code Locale.US}
 851      *                         locale, if the given {@code fieldPosition} is
 852      *                         {@link NumberFormat#INTEGER_FIELD}, the begin index
 853      *                         and end index of {@code fieldPosition} will be set
 854      *                         to 0 and 11, respectively for the output string
 855      *                         {@code 123,456,789}.
 856      * @return The formatted number string
 857      * @exception        ArithmeticException if rounding is needed with rounding
 858      *                   mode being set to RoundingMode.UNNECESSARY
 859      * @see java.text.FieldPosition
 860      */
 861     private StringBuffer format(BigInteger number, StringBuffer result,
 862                                FieldPosition fieldPosition) {
 863         fieldPosition.setBeginIndex(0);
 864         fieldPosition.setEndIndex(0);
 865 
 866         return format(number, result, fieldPosition.getFieldDelegate(), false);
 867     }
 868 
 869     /**
 870      * Format a BigInteger to produce a string.
 871      * @param number    The BigInteger to format
 872      * @param result    where the text is to be appended
 873      * @param delegate notified of locations of sub fields
 874      * @return The formatted number string
 875      * @exception        ArithmeticException if rounding is needed with rounding
 876      *                   mode being set to RoundingMode.UNNECESSARY
 877      * @see java.text.FieldPosition
 878      */
 879     StringBuffer format(BigInteger number, StringBuffer result,
 880                                FieldDelegate delegate, boolean formatLong) {
 881         if (multiplier != 1) {
 882             number = number.multiply(getBigIntegerMultiplier());
 883         }
 884         boolean isNegative = number.signum() == -1;
 885         if (isNegative) {
 886             number = number.negate();
 887         }
 888 
 889         synchronized(digitList) {
 890             int maxIntDigits, minIntDigits, maxFraDigits, minFraDigits, maximumDigits;
 891             if (formatLong) {
 892                 maxIntDigits = super.getMaximumIntegerDigits();
 893                 minIntDigits = super.getMinimumIntegerDigits();
 894                 maxFraDigits = super.getMaximumFractionDigits();
 895                 minFraDigits = super.getMinimumFractionDigits();
 896                 maximumDigits = maxIntDigits + maxFraDigits;
 897             } else {
 898                 maxIntDigits = getMaximumIntegerDigits();
 899                 minIntDigits = getMinimumIntegerDigits();
 900                 maxFraDigits = getMaximumFractionDigits();
 901                 minFraDigits = getMinimumFractionDigits();
 902                 maximumDigits = maxIntDigits + maxFraDigits;
 903                 if (maximumDigits < 0) {
 904                     maximumDigits = Integer.MAX_VALUE;
 905                 }
 906             }
 907 
 908             digitList.set(isNegative, number,
 909                           useExponentialNotation ? maximumDigits : 0);
 910 
 911             return subformat(result, delegate, isNegative, true,
 912                 maxIntDigits, minIntDigits, maxFraDigits, minFraDigits);
 913         }
 914     }
 915 
 916     /**
 917      * Formats an Object producing an <code>AttributedCharacterIterator</code>.
 918      * You can use the returned <code>AttributedCharacterIterator</code>
 919      * to build the resulting String, as well as to determine information
 920      * about the resulting String.
 921      * <p>
 922      * Each attribute key of the AttributedCharacterIterator will be of type
 923      * <code>NumberFormat.Field</code>, with the attribute value being the
 924      * same as the attribute key.
 925      *
 926      * @exception NullPointerException if obj is null.
 927      * @exception IllegalArgumentException when the Format cannot format the
 928      *            given object.
 929      * @exception        ArithmeticException if rounding is needed with rounding
 930      *                   mode being set to RoundingMode.UNNECESSARY
 931      * @param obj The object to format
 932      * @return AttributedCharacterIterator describing the formatted value.
 933      * @since 1.4
 934      */
 935     @Override
 936     public AttributedCharacterIterator formatToCharacterIterator(Object obj) {
 937         CharacterIteratorFieldDelegate delegate =
 938                          new CharacterIteratorFieldDelegate();
 939         StringBuffer sb = new StringBuffer();
 940 
 941         if (obj instanceof Double || obj instanceof Float) {
 942             format(((Number)obj).doubleValue(), sb, delegate);
 943         } else if (obj instanceof Long || obj instanceof Integer ||
 944                    obj instanceof Short || obj instanceof Byte ||
 945                    obj instanceof AtomicInteger || obj instanceof AtomicLong) {
 946             format(((Number)obj).longValue(), sb, delegate);
 947         } else if (obj instanceof BigDecimal) {
 948             format((BigDecimal)obj, sb, delegate);
 949         } else if (obj instanceof BigInteger) {
 950             format((BigInteger)obj, sb, delegate, false);
 951         } else if (obj == null) {
 952             throw new NullPointerException(
 953                 "formatToCharacterIterator must be passed non-null object");
 954         } else {
 955             throw new IllegalArgumentException(
 956                 "Cannot format given Object as a Number");
 957         }
 958         return delegate.getIterator(sb.toString());
 959     }
 960 
 961     // ==== Begin fast-path formatting logic for double =========================
 962 
 963     /* Fast-path formatting will be used for format(double ...) methods iff a
 964      * number of conditions are met (see checkAndSetFastPathStatus()):
 965      * - Only if instance properties meet the right predefined conditions.
 966      * - The abs value of the double to format is <= Integer.MAX_VALUE.
 967      *
 968      * The basic approach is to split the binary to decimal conversion of a
 969      * double value into two phases:
 970      * * The conversion of the integer portion of the double.
 971      * * The conversion of the fractional portion of the double
 972      *   (limited to two or three digits).
 973      *
 974      * The isolation and conversion of the integer portion of the double is
 975      * straightforward. The conversion of the fraction is more subtle and relies
 976      * on some rounding properties of double to the decimal precisions in
 977      * question.  Using the terminology of BigDecimal, this fast-path algorithm
 978      * is applied when a double value has a magnitude less than Integer.MAX_VALUE
 979      * and rounding is to nearest even and the destination format has two or
 980      * three digits of *scale* (digits after the decimal point).
 981      *
 982      * Under a rounding to nearest even policy, the returned result is a digit
 983      * string of a number in the (in this case decimal) destination format
 984      * closest to the exact numerical value of the (in this case binary) input
 985      * value.  If two destination format numbers are equally distant, the one
 986      * with the last digit even is returned.  To compute such a correctly rounded
 987      * value, some information about digits beyond the smallest returned digit
 988      * position needs to be consulted.
 989      *
 990      * In general, a guard digit, a round digit, and a sticky *bit* are needed
 991      * beyond the returned digit position.  If the discarded portion of the input
 992      * is sufficiently large, the returned digit string is incremented.  In round
 993      * to nearest even, this threshold to increment occurs near the half-way
 994      * point between digits.  The sticky bit records if there are any remaining
 995      * trailing digits of the exact input value in the new format; the sticky bit
 996      * is consulted only in close to half-way rounding cases.
 997      *
 998      * Given the computation of the digit and bit values, rounding is then
 999      * reduced to a table lookup problem.  For decimal, the even/odd cases look
1000      * like this:
1001      *
1002      * Last   Round   Sticky
1003      * 6      5       0      => 6   // exactly halfway, return even digit.
1004      * 6      5       1      => 7   // a little bit more than halfway, round up.
1005      * 7      5       0      => 8   // exactly halfway, round up to even.
1006      * 7      5       1      => 8   // a little bit more than halfway, round up.
1007      * With analogous entries for other even and odd last-returned digits.
1008      *
1009      * However, decimal negative powers of 5 smaller than 0.5 are *not* exactly
1010      * representable as binary fraction.  In particular, 0.005 (the round limit
1011      * for a two-digit scale) and 0.0005 (the round limit for a three-digit
1012      * scale) are not representable. Therefore, for input values near these cases
1013      * the sticky bit is known to be set which reduces the rounding logic to:
1014      *
1015      * Last   Round   Sticky
1016      * 6      5       1      => 7   // a little bit more than halfway, round up.
1017      * 7      5       1      => 8   // a little bit more than halfway, round up.
1018      *
1019      * In other words, if the round digit is 5, the sticky bit is known to be
1020      * set.  If the round digit is something other than 5, the sticky bit is not
1021      * relevant.  Therefore, some of the logic about whether or not to increment
1022      * the destination *decimal* value can occur based on tests of *binary*
1023      * computations of the binary input number.
1024      */
1025 
1026     /**
1027      * Check validity of using fast-path for this instance. If fast-path is valid
1028      * for this instance, sets fast-path state as true and initializes fast-path
1029      * utility fields as needed.
1030      *
1031      * This method is supposed to be called rarely, otherwise that will break the
1032      * fast-path performance. That means avoiding frequent changes of the
1033      * properties of the instance, since for most properties, each time a change
1034      * happens, a call to this method is needed at the next format call.
1035      *
1036      * FAST-PATH RULES:
1037      *  Similar to the default DecimalFormat instantiation case.
1038      *  More precisely:
1039      *  - HALF_EVEN rounding mode,
1040      *  - isGroupingUsed() is true,
1041      *  - groupingSize of 3,
1042      *  - multiplier is 1,
1043      *  - Decimal separator not mandatory,
1044      *  - No use of exponential notation,
1045      *  - minimumIntegerDigits is exactly 1 and maximumIntegerDigits at least 10
1046      *  - For number of fractional digits, the exact values found in the default case:
1047      *     Currency : min = max = 2.
1048      *     Decimal  : min = 0. max = 3.
1049      *
1050      */
1051     private boolean checkAndSetFastPathStatus() {
1052 
1053         boolean fastPathWasOn = isFastPath;
1054 
1055         if ((roundingMode == RoundingMode.HALF_EVEN) &&
1056             (isGroupingUsed()) &&
1057             (groupingSize == 3) &&
1058             (multiplier == 1) &&
1059             (!decimalSeparatorAlwaysShown) &&
1060             (!useExponentialNotation)) {
1061 
1062             // The fast-path algorithm is semi-hardcoded against
1063             //  minimumIntegerDigits and maximumIntegerDigits.
1064             isFastPath = ((minimumIntegerDigits == 1) &&
1065                           (maximumIntegerDigits >= 10));
1066 
1067             // The fast-path algorithm is hardcoded against
1068             //  minimumFractionDigits and maximumFractionDigits.
1069             if (isFastPath) {
1070                 if (isCurrencyFormat) {
1071                     if ((minimumFractionDigits != 2) ||
1072                         (maximumFractionDigits != 2))
1073                         isFastPath = false;
1074                 } else if ((minimumFractionDigits != 0) ||
1075                            (maximumFractionDigits != 3))
1076                     isFastPath = false;
1077             }
1078         } else
1079             isFastPath = false;
1080 
1081         resetFastPathData(fastPathWasOn);
1082         fastPathCheckNeeded = false;
1083 
1084         /*
1085          * Returns true after successfully checking the fast path condition and
1086          * setting the fast path data. The return value is used by the
1087          * fastFormat() method to decide whether to call the resetFastPathData
1088          * method to reinitialize fast path data or is it already initialized
1089          * in this method.
1090          */
1091         return true;
1092     }
1093 
1094     private void resetFastPathData(boolean fastPathWasOn) {
1095         // Since some instance properties may have changed while still falling
1096         // in the fast-path case, we need to reinitialize fastPathData anyway.
1097         if (isFastPath) {
1098             // We need to instantiate fastPathData if not already done.
1099             if (fastPathData == null) {
1100                 fastPathData = new FastPathData();
1101             }
1102 
1103             // Sets up the locale specific constants used when formatting.
1104             // '0' is our default representation of zero.
1105             fastPathData.zeroDelta = symbols.getZeroDigit() - '0';
1106             fastPathData.groupingChar = symbols.getGroupingSeparator();
1107 
1108             // Sets up fractional constants related to currency/decimal pattern.
1109             fastPathData.fractionalMaxIntBound = (isCurrencyFormat)
1110                     ? 99 : 999;
1111             fastPathData.fractionalScaleFactor = (isCurrencyFormat)
1112                     ? 100.0d : 1000.0d;
1113 
1114             // Records the need for adding prefix or suffix
1115             fastPathData.positiveAffixesRequired
1116                     = (positivePrefix.length() != 0)
1117                         || (positiveSuffix.length() != 0);
1118             fastPathData.negativeAffixesRequired
1119                     = (negativePrefix.length() != 0)
1120                         || (negativeSuffix.length() != 0);
1121 
1122             // Creates a cached char container for result, with max possible size.
1123             int maxNbIntegralDigits = 10;
1124             int maxNbGroups = 3;
1125             int containerSize
1126                     = Math.max(positivePrefix.length(), negativePrefix.length())
1127                     + maxNbIntegralDigits + maxNbGroups + 1
1128                     + maximumFractionDigits
1129                     + Math.max(positiveSuffix.length(), negativeSuffix.length());
1130 
1131             fastPathData.fastPathContainer = new char[containerSize];
1132 
1133             // Sets up prefix and suffix char arrays constants.
1134             fastPathData.charsPositiveSuffix = positiveSuffix.toCharArray();
1135             fastPathData.charsNegativeSuffix = negativeSuffix.toCharArray();
1136             fastPathData.charsPositivePrefix = positivePrefix.toCharArray();
1137             fastPathData.charsNegativePrefix = negativePrefix.toCharArray();
1138 
1139             // Sets up fixed index positions for integral and fractional digits.
1140             // Sets up decimal point in cached result container.
1141             int longestPrefixLength
1142                     = Math.max(positivePrefix.length(),
1143                             negativePrefix.length());
1144             int decimalPointIndex
1145                     = maxNbIntegralDigits + maxNbGroups + longestPrefixLength;
1146 
1147             fastPathData.integralLastIndex = decimalPointIndex - 1;
1148             fastPathData.fractionalFirstIndex = decimalPointIndex + 1;
1149             fastPathData.fastPathContainer[decimalPointIndex]
1150                     = isCurrencyFormat
1151                             ? symbols.getMonetaryDecimalSeparator()
1152                             : symbols.getDecimalSeparator();
1153 
1154         } else if (fastPathWasOn) {
1155             // Previous state was fast-path and is no more.
1156             // Resets cached array constants.
1157             fastPathData.fastPathContainer = null;
1158             fastPathData.charsPositiveSuffix = null;
1159             fastPathData.charsNegativeSuffix = null;
1160             fastPathData.charsPositivePrefix = null;
1161             fastPathData.charsNegativePrefix = null;
1162         }
1163     }
1164 
1165     /**
1166      * Returns true if rounding-up must be done on {@code scaledFractionalPartAsInt},
1167      * false otherwise.
1168      *
1169      * This is a utility method that takes correct half-even rounding decision on
1170      * passed fractional value at the scaled decimal point (2 digits for currency
1171      * case and 3 for decimal case), when the approximated fractional part after
1172      * scaled decimal point is exactly 0.5d.  This is done by means of exact
1173      * calculations on the {@code fractionalPart} floating-point value.
1174      *
1175      * This method is supposed to be called by private {@code fastDoubleFormat}
1176      * method only.
1177      *
1178      * The algorithms used for the exact calculations are :
1179      *
1180      * The <b><i>FastTwoSum</i></b> algorithm, from T.J.Dekker, described in the
1181      * papers  "<i>A  Floating-Point   Technique  for  Extending  the  Available
1182      * Precision</i>"  by Dekker, and  in "<i>Adaptive  Precision Floating-Point
1183      * Arithmetic and Fast Robust Geometric Predicates</i>" from J.Shewchuk.
1184      *
1185      * A modified version of <b><i>Sum2S</i></b> cascaded summation described in
1186      * "<i>Accurate Sum and Dot Product</i>" from Takeshi Ogita and All.  As
1187      * Ogita says in this paper this is an equivalent of the Kahan-Babuska's
1188      * summation algorithm because we order the terms by magnitude before summing
1189      * them. For this reason we can use the <i>FastTwoSum</i> algorithm rather
1190      * than the more expensive Knuth's <i>TwoSum</i>.
1191      *
1192      * We do this to avoid a more expensive exact "<i>TwoProduct</i>" algorithm,
1193      * like those described in Shewchuk's paper above. See comments in the code
1194      * below.
1195      *
1196      * @param  fractionalPart The  fractional value  on which  we  take rounding
1197      * decision.
1198      * @param scaledFractionalPartAsInt The integral part of the scaled
1199      * fractional value.
1200      *
1201      * @return the decision that must be taken regarding half-even rounding.
1202      */
1203     private boolean exactRoundUp(double fractionalPart,
1204                                  int scaledFractionalPartAsInt) {
1205 
1206         /* exactRoundUp() method is called by fastDoubleFormat() only.
1207          * The precondition expected to be verified by the passed parameters is :
1208          * scaledFractionalPartAsInt ==
1209          *     (int) (fractionalPart * fastPathData.fractionalScaleFactor).
1210          * This is ensured by fastDoubleFormat() code.
1211          */
1212 
1213         /* We first calculate roundoff error made by fastDoubleFormat() on
1214          * the scaled fractional part. We do this with exact calculation on the
1215          * passed fractionalPart. Rounding decision will then be taken from roundoff.
1216          */
1217 
1218         /* ---- TwoProduct(fractionalPart, scale factor (i.e. 1000.0d or 100.0d)).
1219          *
1220          * The below is an optimized exact "TwoProduct" calculation of passed
1221          * fractional part with scale factor, using Ogita's Sum2S cascaded
1222          * summation adapted as Kahan-Babuska equivalent by using FastTwoSum
1223          * (much faster) rather than Knuth's TwoSum.
1224          *
1225          * We can do this because we order the summation from smallest to
1226          * greatest, so that FastTwoSum can be used without any additional error.
1227          *
1228          * The "TwoProduct" exact calculation needs 17 flops. We replace this by
1229          * a cascaded summation of FastTwoSum calculations, each involving an
1230          * exact multiply by a power of 2.
1231          *
1232          * Doing so saves overall 4 multiplications and 1 addition compared to
1233          * using traditional "TwoProduct".
1234          *
1235          * The scale factor is either 100 (currency case) or 1000 (decimal case).
1236          * - when 1000, we replace it by (1024 - 16 - 8) = 1000.
1237          * - when 100,  we replace it by (128  - 32 + 4) =  100.
1238          * Every multiplication by a power of 2 (1024, 128, 32, 16, 8, 4) is exact.
1239          *
1240          */
1241         double approxMax;    // Will always be positive.
1242         double approxMedium; // Will always be negative.
1243         double approxMin;
1244 
1245         double fastTwoSumApproximation = 0.0d;
1246         double fastTwoSumRoundOff = 0.0d;
1247         double bVirtual = 0.0d;
1248 
1249         if (isCurrencyFormat) {
1250             // Scale is 100 = 128 - 32 + 4.
1251             // Multiply by 2**n is a shift. No roundoff. No error.
1252             approxMax    = fractionalPart * 128.00d;
1253             approxMedium = - (fractionalPart * 32.00d);
1254             approxMin    = fractionalPart * 4.00d;
1255         } else {
1256             // Scale is 1000 = 1024 - 16 - 8.
1257             // Multiply by 2**n is a shift. No roundoff. No error.
1258             approxMax    = fractionalPart * 1024.00d;
1259             approxMedium = - (fractionalPart * 16.00d);
1260             approxMin    = - (fractionalPart * 8.00d);
1261         }
1262 
1263         // Shewchuk/Dekker's FastTwoSum(approxMedium, approxMin).
1264         assert(-approxMedium >= Math.abs(approxMin));
1265         fastTwoSumApproximation = approxMedium + approxMin;
1266         bVirtual = fastTwoSumApproximation - approxMedium;
1267         fastTwoSumRoundOff = approxMin - bVirtual;
1268         double approxS1 = fastTwoSumApproximation;
1269         double roundoffS1 = fastTwoSumRoundOff;
1270 
1271         // Shewchuk/Dekker's FastTwoSum(approxMax, approxS1);
1272         assert(approxMax >= Math.abs(approxS1));
1273         fastTwoSumApproximation = approxMax + approxS1;
1274         bVirtual = fastTwoSumApproximation - approxMax;
1275         fastTwoSumRoundOff = approxS1 - bVirtual;
1276         double roundoff1000 = fastTwoSumRoundOff;
1277         double approx1000 = fastTwoSumApproximation;
1278         double roundoffTotal = roundoffS1 + roundoff1000;
1279 
1280         // Shewchuk/Dekker's FastTwoSum(approx1000, roundoffTotal);
1281         assert(approx1000 >= Math.abs(roundoffTotal));
1282         fastTwoSumApproximation = approx1000 + roundoffTotal;
1283         bVirtual = fastTwoSumApproximation - approx1000;
1284 
1285         // Now we have got the roundoff for the scaled fractional
1286         double scaledFractionalRoundoff = roundoffTotal - bVirtual;
1287 
1288         // ---- TwoProduct(fractionalPart, scale (i.e. 1000.0d or 100.0d)) end.
1289 
1290         /* ---- Taking the rounding decision
1291          *
1292          * We take rounding decision based on roundoff and half-even rounding
1293          * rule.
1294          *
1295          * The above TwoProduct gives us the exact roundoff on the approximated
1296          * scaled fractional, and we know that this approximation is exactly
1297          * 0.5d, since that has already been tested by the caller
1298          * (fastDoubleFormat).
1299          *
1300          * Decision comes first from the sign of the calculated exact roundoff.
1301          * - Since being exact roundoff, it cannot be positive with a scaled
1302          *   fractional less than 0.5d, as well as negative with a scaled
1303          *   fractional greater than 0.5d. That leaves us with following 3 cases.
1304          * - positive, thus scaled fractional == 0.500....0fff ==> round-up.
1305          * - negative, thus scaled fractional == 0.499....9fff ==> don't round-up.
1306          * - is zero,  thus scaled fractioanl == 0.5 ==> half-even rounding applies :
1307          *    we round-up only if the integral part of the scaled fractional is odd.
1308          *
1309          */
1310         if (scaledFractionalRoundoff > 0.0) {
1311             return true;
1312         } else if (scaledFractionalRoundoff < 0.0) {
1313             return false;
1314         } else if ((scaledFractionalPartAsInt & 1) != 0) {
1315             return true;
1316         }
1317 
1318         return false;
1319 
1320         // ---- Taking the rounding decision end
1321     }
1322 
1323     /**
1324      * Collects integral digits from passed {@code number}, while setting
1325      * grouping chars as needed. Updates {@code firstUsedIndex} accordingly.
1326      *
1327      * Loops downward starting from {@code backwardIndex} position (inclusive).
1328      *
1329      * @param number  The int value from which we collect digits.
1330      * @param digitsBuffer The char array container where digits and grouping chars
1331      *  are stored.
1332      * @param backwardIndex the position from which we start storing digits in
1333      *  digitsBuffer.
1334      *
1335      */
1336     private void collectIntegralDigits(int number,
1337                                        char[] digitsBuffer,
1338                                        int backwardIndex) {
1339         int index = backwardIndex;
1340         int q;
1341         int r;
1342         while (number > 999) {
1343             // Generates 3 digits per iteration.
1344             q = number / 1000;
1345             r = number - (q << 10) + (q << 4) + (q << 3); // -1024 +16 +8 = 1000.
1346             number = q;
1347 
1348             digitsBuffer[index--] = DigitArrays.DigitOnes1000[r];
1349             digitsBuffer[index--] = DigitArrays.DigitTens1000[r];
1350             digitsBuffer[index--] = DigitArrays.DigitHundreds1000[r];
1351             digitsBuffer[index--] = fastPathData.groupingChar;
1352         }
1353 
1354         // Collects last 3 or less digits.
1355         digitsBuffer[index] = DigitArrays.DigitOnes1000[number];
1356         if (number > 9) {
1357             digitsBuffer[--index]  = DigitArrays.DigitTens1000[number];
1358             if (number > 99)
1359                 digitsBuffer[--index]   = DigitArrays.DigitHundreds1000[number];
1360         }
1361 
1362         fastPathData.firstUsedIndex = index;
1363     }
1364 
1365     /**
1366      * Collects the 2 (currency) or 3 (decimal) fractional digits from passed
1367      * {@code number}, starting at {@code startIndex} position
1368      * inclusive.  There is no punctuation to set here (no grouping chars).
1369      * Updates {@code fastPathData.lastFreeIndex} accordingly.
1370      *
1371      *
1372      * @param number  The int value from which we collect digits.
1373      * @param digitsBuffer The char array container where digits are stored.
1374      * @param startIndex the position from which we start storing digits in
1375      *  digitsBuffer.
1376      *
1377      */
1378     private void collectFractionalDigits(int number,
1379                                          char[] digitsBuffer,
1380                                          int startIndex) {
1381         int index = startIndex;
1382 
1383         char digitOnes = DigitArrays.DigitOnes1000[number];
1384         char digitTens = DigitArrays.DigitTens1000[number];
1385 
1386         if (isCurrencyFormat) {
1387             // Currency case. Always collects fractional digits.
1388             digitsBuffer[index++] = digitTens;
1389             digitsBuffer[index++] = digitOnes;
1390         } else if (number != 0) {
1391             // Decimal case. Hundreds will always be collected
1392             digitsBuffer[index++] = DigitArrays.DigitHundreds1000[number];
1393 
1394             // Ending zeros won't be collected.
1395             if (digitOnes != '0') {
1396                 digitsBuffer[index++] = digitTens;
1397                 digitsBuffer[index++] = digitOnes;
1398             } else if (digitTens != '0')
1399                 digitsBuffer[index++] = digitTens;
1400 
1401         } else
1402             // This is decimal pattern and fractional part is zero.
1403             // We must remove decimal point from result.
1404             index--;
1405 
1406         fastPathData.lastFreeIndex = index;
1407     }
1408 
1409     /**
1410      * Internal utility.
1411      * Adds the passed {@code prefix} and {@code suffix} to {@code container}.
1412      *
1413      * @param container  Char array container which to prepend/append the
1414      *  prefix/suffix.
1415      * @param prefix     Char sequence to prepend as a prefix.
1416      * @param suffix     Char sequence to append as a suffix.
1417      *
1418      */
1419     //    private void addAffixes(boolean isNegative, char[] container) {
1420     private void addAffixes(char[] container, char[] prefix, char[] suffix) {
1421 
1422         // We add affixes only if needed (affix length > 0).
1423         int pl = prefix.length;
1424         int sl = suffix.length;
1425         if (pl != 0) prependPrefix(prefix, pl, container);
1426         if (sl != 0) appendSuffix(suffix, sl, container);
1427 
1428     }
1429 
1430     /**
1431      * Prepends the passed {@code prefix} chars to given result
1432      * {@code container}.  Updates {@code fastPathData.firstUsedIndex}
1433      * accordingly.
1434      *
1435      * @param prefix The prefix characters to prepend to result.
1436      * @param len The number of chars to prepend.
1437      * @param container Char array container which to prepend the prefix
1438      */
1439     private void prependPrefix(char[] prefix,
1440                                int len,
1441                                char[] container) {
1442 
1443         fastPathData.firstUsedIndex -= len;
1444         int startIndex = fastPathData.firstUsedIndex;
1445 
1446         // If prefix to prepend is only 1 char long, just assigns this char.
1447         // If prefix is less or equal 4, we use a dedicated algorithm that
1448         //  has shown to run faster than System.arraycopy.
1449         // If more than 4, we use System.arraycopy.
1450         if (len == 1)
1451             container[startIndex] = prefix[0];
1452         else if (len <= 4) {
1453             int dstLower = startIndex;
1454             int dstUpper = dstLower + len - 1;
1455             int srcUpper = len - 1;
1456             container[dstLower] = prefix[0];
1457             container[dstUpper] = prefix[srcUpper];
1458 
1459             if (len > 2)
1460                 container[++dstLower] = prefix[1];
1461             if (len == 4)
1462                 container[--dstUpper] = prefix[2];
1463         } else
1464             System.arraycopy(prefix, 0, container, startIndex, len);
1465     }
1466 
1467     /**
1468      * Appends the passed {@code suffix} chars to given result
1469      * {@code container}.  Updates {@code fastPathData.lastFreeIndex}
1470      * accordingly.
1471      *
1472      * @param suffix The suffix characters to append to result.
1473      * @param len The number of chars to append.
1474      * @param container Char array container which to append the suffix
1475      */
1476     private void appendSuffix(char[] suffix,
1477                               int len,
1478                               char[] container) {
1479 
1480         int startIndex = fastPathData.lastFreeIndex;
1481 
1482         // If suffix to append is only 1 char long, just assigns this char.
1483         // If suffix is less or equal 4, we use a dedicated algorithm that
1484         //  has shown to run faster than System.arraycopy.
1485         // If more than 4, we use System.arraycopy.
1486         if (len == 1)
1487             container[startIndex] = suffix[0];
1488         else if (len <= 4) {
1489             int dstLower = startIndex;
1490             int dstUpper = dstLower + len - 1;
1491             int srcUpper = len - 1;
1492             container[dstLower] = suffix[0];
1493             container[dstUpper] = suffix[srcUpper];
1494 
1495             if (len > 2)
1496                 container[++dstLower] = suffix[1];
1497             if (len == 4)
1498                 container[--dstUpper] = suffix[2];
1499         } else
1500             System.arraycopy(suffix, 0, container, startIndex, len);
1501 
1502         fastPathData.lastFreeIndex += len;
1503     }
1504 
1505     /**
1506      * Converts digit chars from {@code digitsBuffer} to current locale.
1507      *
1508      * Must be called before adding affixes since we refer to
1509      * {@code fastPathData.firstUsedIndex} and {@code fastPathData.lastFreeIndex},
1510      * and do not support affixes (for speed reason).
1511      *
1512      * We loop backward starting from last used index in {@code fastPathData}.
1513      *
1514      * @param digitsBuffer The char array container where the digits are stored.
1515      */
1516     private void localizeDigits(char[] digitsBuffer) {
1517 
1518         // We will localize only the digits, using the groupingSize,
1519         // and taking into account fractional part.
1520 
1521         // First take into account fractional part.
1522         int digitsCounter =
1523             fastPathData.lastFreeIndex - fastPathData.fractionalFirstIndex;
1524 
1525         // The case when there is no fractional digits.
1526         if (digitsCounter < 0)
1527             digitsCounter = groupingSize;
1528 
1529         // Only the digits remains to localize.
1530         for (int cursor = fastPathData.lastFreeIndex - 1;
1531              cursor >= fastPathData.firstUsedIndex;
1532              cursor--) {
1533             if (digitsCounter != 0) {
1534                 // This is a digit char, we must localize it.
1535                 digitsBuffer[cursor] += fastPathData.zeroDelta;
1536                 digitsCounter--;
1537             } else {
1538                 // Decimal separator or grouping char. Reinit counter only.
1539                 digitsCounter = groupingSize;
1540             }
1541         }
1542     }
1543 
1544     /**
1545      * This is the main entry point for the fast-path format algorithm.
1546      *
1547      * At this point we are sure to be in the expected conditions to run it.
1548      * This algorithm builds the formatted result and puts it in the dedicated
1549      * {@code fastPathData.fastPathContainer}.
1550      *
1551      * @param d the double value to be formatted.
1552      * @param negative Flag precising if {@code d} is negative.
1553      */
1554     private void fastDoubleFormat(double d,
1555                                   boolean negative) {
1556 
1557         char[] container = fastPathData.fastPathContainer;
1558 
1559         /*
1560          * The principle of the algorithm is to :
1561          * - Break the passed double into its integral and fractional parts
1562          *    converted into integers.
1563          * - Then decide if rounding up must be applied or not by following
1564          *    the half-even rounding rule, first using approximated scaled
1565          *    fractional part.
1566          * - For the difficult cases (approximated scaled fractional part
1567          *    being exactly 0.5d), we refine the rounding decision by calling
1568          *    exactRoundUp utility method that both calculates the exact roundoff
1569          *    on the approximation and takes correct rounding decision.
1570          * - We round-up the fractional part if needed, possibly propagating the
1571          *    rounding to integral part if we meet a "all-nine" case for the
1572          *    scaled fractional part.
1573          * - We then collect digits from the resulting integral and fractional
1574          *   parts, also setting the required grouping chars on the fly.
1575          * - Then we localize the collected digits if needed, and
1576          * - Finally prepend/append prefix/suffix if any is needed.
1577          */
1578 
1579         // Exact integral part of d.
1580         int integralPartAsInt = (int) d;
1581 
1582         // Exact fractional part of d (since we subtract it's integral part).
1583         double exactFractionalPart = d - (double) integralPartAsInt;
1584 
1585         // Approximated scaled fractional part of d (due to multiplication).
1586         double scaledFractional =
1587             exactFractionalPart * fastPathData.fractionalScaleFactor;
1588 
1589         // Exact integral part of scaled fractional above.
1590         int fractionalPartAsInt = (int) scaledFractional;
1591 
1592         // Exact fractional part of scaled fractional above.
1593         scaledFractional = scaledFractional - (double) fractionalPartAsInt;
1594 
1595         // Only when scaledFractional is exactly 0.5d do we have to do exact
1596         // calculations and take fine-grained rounding decision, since
1597         // approximated results above may lead to incorrect decision.
1598         // Otherwise comparing against 0.5d (strictly greater or less) is ok.
1599         boolean roundItUp = false;
1600         if (scaledFractional >= 0.5d) {
1601             if (scaledFractional == 0.5d)
1602                 // Rounding need fine-grained decision.
1603                 roundItUp = exactRoundUp(exactFractionalPart, fractionalPartAsInt);
1604             else
1605                 roundItUp = true;
1606 
1607             if (roundItUp) {
1608                 // Rounds up both fractional part (and also integral if needed).
1609                 if (fractionalPartAsInt < fastPathData.fractionalMaxIntBound) {
1610                     fractionalPartAsInt++;
1611                 } else {
1612                     // Propagates rounding to integral part since "all nines" case.
1613                     fractionalPartAsInt = 0;
1614                     integralPartAsInt++;
1615                 }
1616             }
1617         }
1618 
1619         // Collecting digits.
1620         collectFractionalDigits(fractionalPartAsInt, container,
1621                                 fastPathData.fractionalFirstIndex);
1622         collectIntegralDigits(integralPartAsInt, container,
1623                               fastPathData.integralLastIndex);
1624 
1625         // Localizing digits.
1626         if (fastPathData.zeroDelta != 0)
1627             localizeDigits(container);
1628 
1629         // Adding prefix and suffix.
1630         if (negative) {
1631             if (fastPathData.negativeAffixesRequired)
1632                 addAffixes(container,
1633                            fastPathData.charsNegativePrefix,
1634                            fastPathData.charsNegativeSuffix);
1635         } else if (fastPathData.positiveAffixesRequired)
1636             addAffixes(container,
1637                        fastPathData.charsPositivePrefix,
1638                        fastPathData.charsPositiveSuffix);
1639     }
1640 
1641     /**
1642      * A fast-path shortcut of format(double) to be called by NumberFormat, or by
1643      * format(double, ...) public methods.
1644      *
1645      * If instance can be applied fast-path and passed double is not NaN or
1646      * Infinity, is in the integer range, we call {@code fastDoubleFormat}
1647      * after changing {@code d} to its positive value if necessary.
1648      *
1649      * Otherwise returns null by convention since fast-path can't be exercized.
1650      *
1651      * @param d The double value to be formatted
1652      *
1653      * @return the formatted result for {@code d} as a string.
1654      */
1655     String fastFormat(double d) {
1656         boolean isDataSet = false;
1657         // (Re-)Evaluates fast-path status if needed.
1658         if (fastPathCheckNeeded) {
1659             isDataSet = checkAndSetFastPathStatus();
1660         }
1661 
1662         if (!isFastPath )
1663             // DecimalFormat instance is not in a fast-path state.
1664             return null;
1665 
1666         if (!Double.isFinite(d))
1667             // Should not use fast-path for Infinity and NaN.
1668             return null;
1669 
1670         // Extracts and records sign of double value, possibly changing it
1671         // to a positive one, before calling fastDoubleFormat().
1672         boolean negative = false;
1673         if (d < 0.0d) {
1674             negative = true;
1675             d = -d;
1676         } else if (d == 0.0d) {
1677             negative = (Math.copySign(1.0d, d) == -1.0d);
1678             d = +0.0d;
1679         }
1680 
1681         if (d > MAX_INT_AS_DOUBLE)
1682             // Filters out values that are outside expected fast-path range
1683             return null;
1684         else {
1685             if (!isDataSet) {
1686                 /*
1687                  * If the fast path data is not set through
1688                  * checkAndSetFastPathStatus() and fulfil the
1689                  * fast path conditions then reset the data
1690                  * directly through resetFastPathData()
1691                  */
1692                 resetFastPathData(isFastPath);
1693             }
1694             fastDoubleFormat(d, negative);
1695 
1696         }
1697 
1698 
1699         // Returns a new string from updated fastPathContainer.
1700         return new String(fastPathData.fastPathContainer,
1701                           fastPathData.firstUsedIndex,
1702                           fastPathData.lastFreeIndex - fastPathData.firstUsedIndex);
1703 
1704     }
1705 
1706     /**
1707      * Sets the {@code DigitList} used by this {@code DecimalFormat}
1708      * instance.
1709      * @param number the number to format
1710      * @param isNegative true, if the number is negative; false otherwise
1711      * @param maxDigits the max digits
1712      */
1713     void setDigitList(Number number, boolean isNegative, int maxDigits) {
1714 
1715         if (number instanceof Double) {
1716             digitList.set(isNegative, (Double) number, maxDigits, true);
1717         } else if (number instanceof BigDecimal) {
1718             digitList.set(isNegative, (BigDecimal) number, maxDigits, true);
1719         } else if (number instanceof Long) {
1720             digitList.set(isNegative, (Long) number, maxDigits);
1721         } else if (number instanceof BigInteger) {
1722             digitList.set(isNegative, (BigInteger) number, maxDigits);
1723         }
1724     }
1725 
1726     // ======== End fast-path formating logic for double =========================
1727 
1728     /**
1729      * Complete the formatting of a finite number.  On entry, the digitList must
1730      * be filled in with the correct digits.
1731      */
1732     private StringBuffer subformat(StringBuffer result, FieldDelegate delegate,
1733             boolean isNegative, boolean isInteger,
1734             int maxIntDigits, int minIntDigits,
1735             int maxFraDigits, int minFraDigits) {
1736 
1737         // process prefix
1738         if (isNegative) {
1739             append(result, negativePrefix, delegate,
1740                     getNegativePrefixFieldPositions(), Field.SIGN);
1741         } else {
1742             append(result, positivePrefix, delegate,
1743                     getPositivePrefixFieldPositions(), Field.SIGN);
1744         }
1745 
1746         // process number
1747         subformatNumber(result, delegate, isNegative, isInteger,
1748                 maxIntDigits, minIntDigits, maxFraDigits, minFraDigits);
1749 
1750         // process suffix
1751         if (isNegative) {
1752             append(result, negativeSuffix, delegate,
1753                     getNegativeSuffixFieldPositions(), Field.SIGN);
1754         } else {
1755             append(result, positiveSuffix, delegate,
1756                     getPositiveSuffixFieldPositions(), Field.SIGN);
1757         }
1758 
1759         return result;
1760     }
1761 
1762     /**
1763      * Subformats number part using the {@code DigitList} of this
1764      * {@code DecimalFormat} instance.
1765      * @param result where the text is to be appended
1766      * @param delegate notified of the location of sub fields
1767      * @param isNegative true, if the number is negative; false otherwise
1768      * @param isInteger true, if the number is an integer; false otherwise
1769      * @param maxIntDigits maximum integer digits
1770      * @param minIntDigits minimum integer digits
1771      * @param maxFraDigits maximum fraction digits
1772      * @param minFraDigits minimum fraction digits
1773      */
1774     void subformatNumber(StringBuffer result, FieldDelegate delegate,
1775             boolean isNegative, boolean isInteger,
1776             int maxIntDigits, int minIntDigits,
1777             int maxFraDigits, int minFraDigits) {
1778 
1779         char grouping = symbols.getGroupingSeparator();
1780         char zero = symbols.getZeroDigit();
1781         int zeroDelta = zero - '0'; // '0' is the DigitList representation of zero
1782 
1783         char decimal = isCurrencyFormat ?
1784                 symbols.getMonetaryDecimalSeparator() :
1785                 symbols.getDecimalSeparator();
1786 
1787         /* Per bug 4147706, DecimalFormat must respect the sign of numbers which
1788          * format as zero.  This allows sensible computations and preserves
1789          * relations such as signum(1/x) = signum(x), where x is +Infinity or
1790          * -Infinity.  Prior to this fix, we always formatted zero values as if
1791          * they were positive.  Liu 7/6/98.
1792          */
1793         if (digitList.isZero()) {
1794             digitList.decimalAt = 0; // Normalize
1795         }
1796 
1797         if (useExponentialNotation) {
1798             int iFieldStart = result.length();
1799             int iFieldEnd = -1;
1800             int fFieldStart = -1;
1801 
1802             // Minimum integer digits are handled in exponential format by
1803             // adjusting the exponent.  For example, 0.01234 with 3 minimum
1804             // integer digits is "123.4E-4".
1805             // Maximum integer digits are interpreted as indicating the
1806             // repeating range.  This is useful for engineering notation, in
1807             // which the exponent is restricted to a multiple of 3.  For
1808             // example, 0.01234 with 3 maximum integer digits is "12.34e-3".
1809             // If maximum integer digits are > 1 and are larger than
1810             // minimum integer digits, then minimum integer digits are
1811             // ignored.
1812             int exponent = digitList.decimalAt;
1813             int repeat = maxIntDigits;
1814             int minimumIntegerDigits = minIntDigits;
1815             if (repeat > 1 && repeat > minIntDigits) {
1816                 // A repeating range is defined; adjust to it as follows.
1817                 // If repeat == 3, we have 6,5,4=>3; 3,2,1=>0; 0,-1,-2=>-3;
1818                 // -3,-4,-5=>-6, etc. This takes into account that the
1819                 // exponent we have here is off by one from what we expect;
1820                 // it is for the format 0.MMMMMx10^n.
1821                 if (exponent >= 1) {
1822                     exponent = ((exponent - 1) / repeat) * repeat;
1823                 } else {
1824                     // integer division rounds towards 0
1825                     exponent = ((exponent - repeat) / repeat) * repeat;
1826                 }
1827                 minimumIntegerDigits = 1;
1828             } else {
1829                 // No repeating range is defined; use minimum integer digits.
1830                 exponent -= minimumIntegerDigits;
1831             }
1832 
1833             // We now output a minimum number of digits, and more if there
1834             // are more digits, up to the maximum number of digits.  We
1835             // place the decimal point after the "integer" digits, which
1836             // are the first (decimalAt - exponent) digits.
1837             int minimumDigits = minIntDigits + minFraDigits;
1838             if (minimumDigits < 0) {    // overflow?
1839                 minimumDigits = Integer.MAX_VALUE;
1840             }
1841 
1842             // The number of integer digits is handled specially if the number
1843             // is zero, since then there may be no digits.
1844             int integerDigits = digitList.isZero() ? minimumIntegerDigits :
1845                     digitList.decimalAt - exponent;
1846             if (minimumDigits < integerDigits) {
1847                 minimumDigits = integerDigits;
1848             }
1849             int totalDigits = digitList.count;
1850             if (minimumDigits > totalDigits) {
1851                 totalDigits = minimumDigits;
1852             }
1853             boolean addedDecimalSeparator = false;
1854 
1855             for (int i=0; i<totalDigits; ++i) {
1856                 if (i == integerDigits) {
1857                     // Record field information for caller.
1858                     iFieldEnd = result.length();
1859 
1860                     result.append(decimal);
1861                     addedDecimalSeparator = true;
1862 
1863                     // Record field information for caller.
1864                     fFieldStart = result.length();
1865                 }
1866                 result.append((i < digitList.count) ?
1867                         (char)(digitList.digits[i] + zeroDelta) :
1868                         zero);
1869             }
1870 
1871             if (decimalSeparatorAlwaysShown && totalDigits == integerDigits) {
1872                 // Record field information for caller.
1873                 iFieldEnd = result.length();
1874 
1875                 result.append(decimal);
1876                 addedDecimalSeparator = true;
1877 
1878                 // Record field information for caller.
1879                 fFieldStart = result.length();
1880             }
1881 
1882             // Record field information
1883             if (iFieldEnd == -1) {
1884                 iFieldEnd = result.length();
1885             }
1886             delegate.formatted(INTEGER_FIELD, Field.INTEGER, Field.INTEGER,
1887                     iFieldStart, iFieldEnd, result);
1888             if (addedDecimalSeparator) {
1889                 delegate.formatted(Field.DECIMAL_SEPARATOR,
1890                         Field.DECIMAL_SEPARATOR,
1891                         iFieldEnd, fFieldStart, result);
1892             }
1893             if (fFieldStart == -1) {
1894                 fFieldStart = result.length();
1895             }
1896             delegate.formatted(FRACTION_FIELD, Field.FRACTION, Field.FRACTION,
1897                     fFieldStart, result.length(), result);
1898 
1899             // The exponent is output using the pattern-specified minimum
1900             // exponent digits.  There is no maximum limit to the exponent
1901             // digits, since truncating the exponent would result in an
1902             // unacceptable inaccuracy.
1903             int fieldStart = result.length();
1904 
1905             result.append(symbols.getExponentSeparator());
1906 
1907             delegate.formatted(Field.EXPONENT_SYMBOL, Field.EXPONENT_SYMBOL,
1908                     fieldStart, result.length(), result);
1909 
1910             // For zero values, we force the exponent to zero.  We
1911             // must do this here, and not earlier, because the value
1912             // is used to determine integer digit count above.
1913             if (digitList.isZero()) {
1914                 exponent = 0;
1915             }
1916 
1917             boolean negativeExponent = exponent < 0;
1918             if (negativeExponent) {
1919                 exponent = -exponent;
1920                 fieldStart = result.length();
1921                 result.append(symbols.getMinusSign());
1922                 delegate.formatted(Field.EXPONENT_SIGN, Field.EXPONENT_SIGN,
1923                         fieldStart, result.length(), result);
1924             }
1925             digitList.set(negativeExponent, exponent);
1926 
1927             int eFieldStart = result.length();
1928 
1929             for (int i=digitList.decimalAt; i<minExponentDigits; ++i) {
1930                 result.append(zero);
1931             }
1932             for (int i=0; i<digitList.decimalAt; ++i) {
1933                 result.append((i < digitList.count) ?
1934                         (char)(digitList.digits[i] + zeroDelta) : zero);
1935             }
1936             delegate.formatted(Field.EXPONENT, Field.EXPONENT, eFieldStart,
1937                     result.length(), result);
1938         } else {
1939             int iFieldStart = result.length();
1940 
1941             // Output the integer portion.  Here 'count' is the total
1942             // number of integer digits we will display, including both
1943             // leading zeros required to satisfy getMinimumIntegerDigits,
1944             // and actual digits present in the number.
1945             int count = minIntDigits;
1946             int digitIndex = 0; // Index into digitList.fDigits[]
1947             if (digitList.decimalAt > 0 && count < digitList.decimalAt) {
1948                 count = digitList.decimalAt;
1949             }
1950 
1951             // Handle the case where getMaximumIntegerDigits() is smaller
1952             // than the real number of integer digits.  If this is so, we
1953             // output the least significant max integer digits.  For example,
1954             // the value 1997 printed with 2 max integer digits is just "97".
1955             if (count > maxIntDigits) {
1956                 count = maxIntDigits;
1957                 digitIndex = digitList.decimalAt - count;
1958             }
1959 
1960             int sizeBeforeIntegerPart = result.length();
1961             for (int i=count-1; i>=0; --i) {
1962                 if (i < digitList.decimalAt && digitIndex < digitList.count) {
1963                     // Output a real digit
1964                     result.append((char)(digitList.digits[digitIndex++] + zeroDelta));
1965                 } else {
1966                     // Output a leading zero
1967                     result.append(zero);
1968                 }
1969 
1970                 // Output grouping separator if necessary.  Don't output a
1971                 // grouping separator if i==0 though; that's at the end of
1972                 // the integer part.
1973                 if (isGroupingUsed() && i>0 && (groupingSize != 0) &&
1974                         (i % groupingSize == 0)) {
1975                     int gStart = result.length();
1976                     result.append(grouping);
1977                     delegate.formatted(Field.GROUPING_SEPARATOR,
1978                             Field.GROUPING_SEPARATOR, gStart,
1979                             result.length(), result);
1980                 }
1981             }
1982 
1983             // Determine whether or not there are any printable fractional
1984             // digits.  If we've used up the digits we know there aren't.
1985             boolean fractionPresent = (minFraDigits > 0) ||
1986                     (!isInteger && digitIndex < digitList.count);
1987 
1988             // If there is no fraction present, and we haven't printed any
1989             // integer digits, then print a zero.  Otherwise we won't print
1990             // _any_ digits, and we won't be able to parse this string.
1991             if (!fractionPresent && result.length() == sizeBeforeIntegerPart) {
1992                 result.append(zero);
1993             }
1994 
1995             delegate.formatted(INTEGER_FIELD, Field.INTEGER, Field.INTEGER,
1996                     iFieldStart, result.length(), result);
1997 
1998             // Output the decimal separator if we always do so.
1999             int sStart = result.length();
2000             if (decimalSeparatorAlwaysShown || fractionPresent) {
2001                 result.append(decimal);
2002             }
2003 
2004             if (sStart != result.length()) {
2005                 delegate.formatted(Field.DECIMAL_SEPARATOR,
2006                         Field.DECIMAL_SEPARATOR,
2007                         sStart, result.length(), result);
2008             }
2009             int fFieldStart = result.length();
2010 
2011             for (int i=0; i < maxFraDigits; ++i) {
2012                 // Here is where we escape from the loop.  We escape if we've
2013                 // output the maximum fraction digits (specified in the for
2014                 // expression above).
2015                 // We also stop when we've output the minimum digits and either:
2016                 // we have an integer, so there is no fractional stuff to
2017                 // display, or we're out of significant digits.
2018                 if (i >= minFraDigits &&
2019                         (isInteger || digitIndex >= digitList.count)) {
2020                     break;
2021                 }
2022 
2023                 // Output leading fractional zeros. These are zeros that come
2024                 // after the decimal but before any significant digits. These
2025                 // are only output if abs(number being formatted) < 1.0.
2026                 if (-1-i > (digitList.decimalAt-1)) {
2027                     result.append(zero);
2028                     continue;
2029                 }
2030 
2031                 // Output a digit, if we have any precision left, or a
2032                 // zero if we don't.  We don't want to output noise digits.
2033                 if (!isInteger && digitIndex < digitList.count) {
2034                     result.append((char)(digitList.digits[digitIndex++] + zeroDelta));
2035                 } else {
2036                     result.append(zero);
2037                 }
2038             }
2039 
2040             // Record field information for caller.
2041             delegate.formatted(FRACTION_FIELD, Field.FRACTION, Field.FRACTION,
2042                     fFieldStart, result.length(), result);
2043         }
2044     }
2045 
2046     /**
2047      * Appends the String <code>string</code> to <code>result</code>.
2048      * <code>delegate</code> is notified of all  the
2049      * <code>FieldPosition</code>s in <code>positions</code>.
2050      * <p>
2051      * If one of the <code>FieldPosition</code>s in <code>positions</code>
2052      * identifies a <code>SIGN</code> attribute, it is mapped to
2053      * <code>signAttribute</code>. This is used
2054      * to map the <code>SIGN</code> attribute to the <code>EXPONENT</code>
2055      * attribute as necessary.
2056      * <p>
2057      * This is used by <code>subformat</code> to add the prefix/suffix.
2058      */
2059     private void append(StringBuffer result, String string,
2060                         FieldDelegate delegate,
2061                         FieldPosition[] positions,
2062                         Format.Field signAttribute) {
2063         int start = result.length();
2064 
2065         if (string.length() > 0) {
2066             result.append(string);
2067             for (int counter = 0, max = positions.length; counter < max;
2068                  counter++) {
2069                 FieldPosition fp = positions[counter];
2070                 Format.Field attribute = fp.getFieldAttribute();
2071 
2072                 if (attribute == Field.SIGN) {
2073                     attribute = signAttribute;
2074                 }
2075                 delegate.formatted(attribute, attribute,
2076                                    start + fp.getBeginIndex(),
2077                                    start + fp.getEndIndex(), result);
2078             }
2079         }
2080     }
2081 
2082     /**
2083      * Parses text from a string to produce a <code>Number</code>.
2084      * <p>
2085      * The method attempts to parse text starting at the index given by
2086      * <code>pos</code>.
2087      * If parsing succeeds, then the index of <code>pos</code> is updated
2088      * to the index after the last character used (parsing does not necessarily
2089      * use all characters up to the end of the string), and the parsed
2090      * number is returned. The updated <code>pos</code> can be used to
2091      * indicate the starting point for the next call to this method.
2092      * If an error occurs, then the index of <code>pos</code> is not
2093      * changed, the error index of <code>pos</code> is set to the index of
2094      * the character where the error occurred, and null is returned.
2095      * <p>
2096      * The subclass returned depends on the value of {@link #isParseBigDecimal}
2097      * as well as on the string being parsed.
2098      * <ul>
2099      *   <li>If <code>isParseBigDecimal()</code> is false (the default),
2100      *       most integer values are returned as <code>Long</code>
2101      *       objects, no matter how they are written: <code>"17"</code> and
2102      *       <code>"17.000"</code> both parse to <code>Long(17)</code>.
2103      *       Values that cannot fit into a <code>Long</code> are returned as
2104      *       <code>Double</code>s. This includes values with a fractional part,
2105      *       infinite values, <code>NaN</code>, and the value -0.0.
2106      *       <code>DecimalFormat</code> does <em>not</em> decide whether to
2107      *       return a <code>Double</code> or a <code>Long</code> based on the
2108      *       presence of a decimal separator in the source string. Doing so
2109      *       would prevent integers that overflow the mantissa of a double,
2110      *       such as <code>"-9,223,372,036,854,775,808.00"</code>, from being
2111      *       parsed accurately.
2112      *       <p>
2113      *       Callers may use the <code>Number</code> methods
2114      *       <code>doubleValue</code>, <code>longValue</code>, etc., to obtain
2115      *       the type they want.
2116      *   <li>If <code>isParseBigDecimal()</code> is true, values are returned
2117      *       as <code>BigDecimal</code> objects. The values are the ones
2118      *       constructed by {@link java.math.BigDecimal#BigDecimal(String)}
2119      *       for corresponding strings in locale-independent format. The
2120      *       special cases negative and positive infinity and NaN are returned
2121      *       as <code>Double</code> instances holding the values of the
2122      *       corresponding <code>Double</code> constants.
2123      * </ul>
2124      * <p>
2125      * <code>DecimalFormat</code> parses all Unicode characters that represent
2126      * decimal digits, as defined by <code>Character.digit()</code>. In
2127      * addition, <code>DecimalFormat</code> also recognizes as digits the ten
2128      * consecutive characters starting with the localized zero digit defined in
2129      * the <code>DecimalFormatSymbols</code> object.
2130      *
2131      * @param text the string to be parsed
2132      * @param pos  A <code>ParsePosition</code> object with index and error
2133      *             index information as described above.
2134      * @return     the parsed value, or <code>null</code> if the parse fails
2135      * @exception  NullPointerException if <code>text</code> or
2136      *             <code>pos</code> is null.
2137      */
2138     @Override
2139     public Number parse(String text, ParsePosition pos) {
2140         // special case NaN
2141         if (text.regionMatches(pos.index, symbols.getNaN(), 0, symbols.getNaN().length())) {
2142             pos.index = pos.index + symbols.getNaN().length();
2143             return Double.valueOf(Double.NaN);
2144         }
2145 
2146         boolean[] status = new boolean[STATUS_LENGTH];
2147         if (!subparse(text, pos, positivePrefix, negativePrefix, digitList, false, status)) {
2148             return null;
2149         }
2150 
2151         // special case INFINITY
2152         if (status[STATUS_INFINITE]) {
2153             if (status[STATUS_POSITIVE] == (multiplier >= 0)) {
2154                 return Double.valueOf(Double.POSITIVE_INFINITY);
2155             } else {
2156                 return Double.valueOf(Double.NEGATIVE_INFINITY);
2157             }
2158         }
2159 
2160         if (multiplier == 0) {
2161             if (digitList.isZero()) {
2162                 return Double.valueOf(Double.NaN);
2163             } else if (status[STATUS_POSITIVE]) {
2164                 return Double.valueOf(Double.POSITIVE_INFINITY);
2165             } else {
2166                 return Double.valueOf(Double.NEGATIVE_INFINITY);
2167             }
2168         }
2169 
2170         if (isParseBigDecimal()) {
2171             BigDecimal bigDecimalResult = digitList.getBigDecimal();
2172 
2173             if (multiplier != 1) {
2174                 try {
2175                     bigDecimalResult = bigDecimalResult.divide(getBigDecimalMultiplier());
2176                 }
2177                 catch (ArithmeticException e) {  // non-terminating decimal expansion
2178                     bigDecimalResult = bigDecimalResult.divide(getBigDecimalMultiplier(), roundingMode);
2179                 }
2180             }
2181 
2182             if (!status[STATUS_POSITIVE]) {
2183                 bigDecimalResult = bigDecimalResult.negate();
2184             }
2185             return bigDecimalResult;
2186         } else {
2187             boolean gotDouble = true;
2188             boolean gotLongMinimum = false;
2189             double  doubleResult = 0.0;
2190             long    longResult = 0;
2191 
2192             // Finally, have DigitList parse the digits into a value.
2193             if (digitList.fitsIntoLong(status[STATUS_POSITIVE], isParseIntegerOnly())) {
2194                 gotDouble = false;
2195                 longResult = digitList.getLong();
2196                 if (longResult < 0) {  // got Long.MIN_VALUE
2197                     gotLongMinimum = true;
2198                 }
2199             } else {
2200                 doubleResult = digitList.getDouble();
2201             }
2202 
2203             // Divide by multiplier. We have to be careful here not to do
2204             // unneeded conversions between double and long.
2205             if (multiplier != 1) {
2206                 if (gotDouble) {
2207                     doubleResult /= multiplier;
2208                 } else {
2209                     // Avoid converting to double if we can
2210                     if (longResult % multiplier == 0) {
2211                         longResult /= multiplier;
2212                     } else {
2213                         doubleResult = ((double)longResult) / multiplier;
2214                         gotDouble = true;
2215                     }
2216                 }
2217             }
2218 
2219             if (!status[STATUS_POSITIVE] && !gotLongMinimum) {
2220                 doubleResult = -doubleResult;
2221                 longResult = -longResult;
2222             }
2223 
2224             // At this point, if we divided the result by the multiplier, the
2225             // result may fit into a long.  We check for this case and return
2226             // a long if possible.
2227             // We must do this AFTER applying the negative (if appropriate)
2228             // in order to handle the case of LONG_MIN; otherwise, if we do
2229             // this with a positive value -LONG_MIN, the double is > 0, but
2230             // the long is < 0. We also must retain a double in the case of
2231             // -0.0, which will compare as == to a long 0 cast to a double
2232             // (bug 4162852).
2233             if (multiplier != 1 && gotDouble) {
2234                 longResult = (long)doubleResult;
2235                 gotDouble = ((doubleResult != (double)longResult) ||
2236                             (doubleResult == 0.0 && 1/doubleResult < 0.0)) &&
2237                             !isParseIntegerOnly();
2238             }
2239 
2240             // cast inside of ?: because of binary numeric promotion, JLS 15.25
2241             return gotDouble ? (Number)doubleResult : (Number)longResult;
2242         }
2243     }
2244 
2245     /**
2246      * Return a BigInteger multiplier.
2247      */
2248     private BigInteger getBigIntegerMultiplier() {
2249         if (bigIntegerMultiplier == null) {
2250             bigIntegerMultiplier = BigInteger.valueOf(multiplier);
2251         }
2252         return bigIntegerMultiplier;
2253     }
2254     private transient BigInteger bigIntegerMultiplier;
2255 
2256     /**
2257      * Return a BigDecimal multiplier.
2258      */
2259     private BigDecimal getBigDecimalMultiplier() {
2260         if (bigDecimalMultiplier == null) {
2261             bigDecimalMultiplier = new BigDecimal(multiplier);
2262         }
2263         return bigDecimalMultiplier;
2264     }
2265     private transient BigDecimal bigDecimalMultiplier;
2266 
2267     private static final int STATUS_INFINITE = 0;
2268     private static final int STATUS_POSITIVE = 1;
2269     private static final int STATUS_LENGTH   = 2;
2270 
2271     /**
2272      * Parse the given text into a number.  The text is parsed beginning at
2273      * parsePosition, until an unparseable character is seen.
2274      * @param text The string to parse.
2275      * @param parsePosition The position at which to being parsing.  Upon
2276      * return, the first unparseable character.
2277      * @param digits The DigitList to set to the parsed value.
2278      * @param isExponent If true, parse an exponent.  This means no
2279      * infinite values and integer only.
2280      * @param status Upon return contains boolean status flags indicating
2281      * whether the value was infinite and whether it was positive.
2282      */
2283     private final boolean subparse(String text, ParsePosition parsePosition,
2284                                    String positivePrefix, String negativePrefix,
2285                                    DigitList digits, boolean isExponent,
2286                                    boolean status[]) {
2287         int position = parsePosition.index;
2288         int oldStart = parsePosition.index;
2289         boolean gotPositive, gotNegative;
2290 
2291         // check for positivePrefix; take longest
2292         gotPositive = text.regionMatches(position, positivePrefix, 0,
2293                 positivePrefix.length());
2294         gotNegative = text.regionMatches(position, negativePrefix, 0,
2295                 negativePrefix.length());
2296 
2297         if (gotPositive && gotNegative) {
2298             if (positivePrefix.length() > negativePrefix.length()) {
2299                 gotNegative = false;
2300             } else if (positivePrefix.length() < negativePrefix.length()) {
2301                 gotPositive = false;
2302             }
2303         }
2304 
2305         if (gotPositive) {
2306             position += positivePrefix.length();
2307         } else if (gotNegative) {
2308             position += negativePrefix.length();
2309         } else {
2310             parsePosition.errorIndex = position;
2311             return false;
2312         }
2313 
2314         position = subparseNumber(text, position, digits, true, isExponent, status);
2315         if (position == -1) {
2316             parsePosition.index = oldStart;
2317             parsePosition.errorIndex = oldStart;
2318             return false;
2319         }
2320 
2321         // check for suffix
2322         if (!isExponent) {
2323             if (gotPositive) {
2324                 gotPositive = text.regionMatches(position,positiveSuffix,0,
2325                         positiveSuffix.length());
2326             }
2327             if (gotNegative) {
2328                 gotNegative = text.regionMatches(position,negativeSuffix,0,
2329                         negativeSuffix.length());
2330             }
2331 
2332             // if both match, take longest
2333             if (gotPositive && gotNegative) {
2334                 if (positiveSuffix.length() > negativeSuffix.length()) {
2335                     gotNegative = false;
2336                 } else if (positiveSuffix.length() < negativeSuffix.length()) {
2337                     gotPositive = false;
2338                 }
2339             }
2340 
2341             // fail if neither or both
2342             if (gotPositive == gotNegative) {
2343                 parsePosition.errorIndex = position;
2344                 return false;
2345             }
2346 
2347             parsePosition.index = position +
2348                     (gotPositive ? positiveSuffix.length() : negativeSuffix.length()); // mark success!
2349         } else {
2350             parsePosition.index = position;
2351         }
2352 
2353         status[STATUS_POSITIVE] = gotPositive;
2354         if (parsePosition.index == oldStart) {
2355             parsePosition.errorIndex = position;
2356             return false;
2357         }
2358         return true;
2359     }
2360 
2361     /**
2362      * Parses a number from the given {@code text}. The text is parsed
2363      * beginning at position, until an unparseable character is seen.
2364      *
2365      * @param text the string to parse
2366      * @param position the position at which parsing begins
2367      * @param digits the DigitList to set to the parsed value
2368      * @param checkExponent whether to check for exponential number
2369      * @param isExponent if the exponential part is encountered
2370      * @param status upon return contains boolean status flags indicating
2371      *               whether the value is infinite and whether it is
2372      *               positive
2373      * @return returns the position of the first unparseable character or
2374      *         -1 in case of no valid number parsed
2375      */
2376     int subparseNumber(String text, int position,
2377                        DigitList digits, boolean checkExponent,
2378                        boolean isExponent, boolean status[]) {
2379         // process digits or Inf, find decimal position
2380         status[STATUS_INFINITE] = false;
2381         if (!isExponent && text.regionMatches(position,symbols.getInfinity(),0,
2382                 symbols.getInfinity().length())) {
2383             position += symbols.getInfinity().length();
2384             status[STATUS_INFINITE] = true;
2385         } else {
2386             // We now have a string of digits, possibly with grouping symbols,
2387             // and decimal points.  We want to process these into a DigitList.
2388             // We don't want to put a bunch of leading zeros into the DigitList
2389             // though, so we keep track of the location of the decimal point,
2390             // put only significant digits into the DigitList, and adjust the
2391             // exponent as needed.
2392 
2393             digits.decimalAt = digits.count = 0;
2394             char zero = symbols.getZeroDigit();
2395             char decimal = isCurrencyFormat ?
2396                     symbols.getMonetaryDecimalSeparator() :
2397                     symbols.getDecimalSeparator();
2398             char grouping = symbols.getGroupingSeparator();
2399             String exponentString = symbols.getExponentSeparator();
2400             boolean sawDecimal = false;
2401             boolean sawExponent = false;
2402             boolean sawDigit = false;
2403             int exponent = 0; // Set to the exponent value, if any
2404 
2405             // We have to track digitCount ourselves, because digits.count will
2406             // pin when the maximum allowable digits is reached.
2407             int digitCount = 0;
2408 
2409             int backup = -1;
2410             for (; position < text.length(); ++position) {
2411                 char ch = text.charAt(position);
2412 
2413                 /* We recognize all digit ranges, not only the Latin digit range
2414                  * '0'..'9'.  We do so by using the Character.digit() method,
2415                  * which converts a valid Unicode digit to the range 0..9.
2416                  *
2417                  * The character 'ch' may be a digit.  If so, place its value
2418                  * from 0 to 9 in 'digit'.  First try using the locale digit,
2419                  * which may or MAY NOT be a standard Unicode digit range.  If
2420                  * this fails, try using the standard Unicode digit ranges by
2421                  * calling Character.digit().  If this also fails, digit will
2422                  * have a value outside the range 0..9.
2423                  */
2424                 int digit = ch - zero;
2425                 if (digit < 0 || digit > 9) {
2426                     digit = Character.digit(ch, 10);
2427                 }
2428 
2429                 if (digit == 0) {
2430                     // Cancel out backup setting (see grouping handler below)
2431                     backup = -1; // Do this BEFORE continue statement below!!!
2432                     sawDigit = true;
2433 
2434                     // Handle leading zeros
2435                     if (digits.count == 0) {
2436                         // Ignore leading zeros in integer part of number.
2437                         if (!sawDecimal) {
2438                             continue;
2439                         }
2440 
2441                         // If we have seen the decimal, but no significant
2442                         // digits yet, then we account for leading zeros by
2443                         // decrementing the digits.decimalAt into negative
2444                         // values.
2445                         --digits.decimalAt;
2446                     } else {
2447                         ++digitCount;
2448                         digits.append((char)(digit + '0'));
2449                     }
2450                 } else if (digit > 0 && digit <= 9) { // [sic] digit==0 handled above
2451                     sawDigit = true;
2452                     ++digitCount;
2453                     digits.append((char)(digit + '0'));
2454 
2455                     // Cancel out backup setting (see grouping handler below)
2456                     backup = -1;
2457                 } else if (!isExponent && ch == decimal) {
2458                     // If we're only parsing integers, or if we ALREADY saw the
2459                     // decimal, then don't parse this one.
2460                     if (isParseIntegerOnly() || sawDecimal) {
2461                         break;
2462                     }
2463                     digits.decimalAt = digitCount; // Not digits.count!
2464                     sawDecimal = true;
2465                 } else if (!isExponent && ch == grouping && isGroupingUsed()) {
2466                     if (sawDecimal) {
2467                         break;
2468                     }
2469                     // Ignore grouping characters, if we are using them, but
2470                     // require that they be followed by a digit.  Otherwise
2471                     // we backup and reprocess them.
2472                     backup = position;
2473                 } else if (checkExponent && !isExponent && text.regionMatches(position, exponentString, 0, exponentString.length())
2474                         && !sawExponent) {
2475                     // Process the exponent by recursively calling this method.
2476                     ParsePosition pos = new ParsePosition(position + exponentString.length());
2477                     boolean[] stat = new boolean[STATUS_LENGTH];
2478                     DigitList exponentDigits = new DigitList();
2479 
2480                     if (subparse(text, pos, "", Character.toString(symbols.getMinusSign()), exponentDigits, true, stat) &&
2481                             exponentDigits.fitsIntoLong(stat[STATUS_POSITIVE], true)) {
2482                         position = pos.index; // Advance past the exponent
2483                         exponent = (int)exponentDigits.getLong();
2484                         if (!stat[STATUS_POSITIVE]) {
2485                             exponent = -exponent;
2486                         }
2487                         sawExponent = true;
2488                     }
2489                     break; // Whether we fail or succeed, we exit this loop
2490                 } else {
2491                     break;
2492                 }
2493             }
2494 
2495             if (backup != -1) {
2496                 position = backup;
2497             }
2498 
2499             // If there was no decimal point we have an integer
2500             if (!sawDecimal) {
2501                 digits.decimalAt = digitCount; // Not digits.count!
2502             }
2503 
2504             // Adjust for exponent, if any
2505             digits.decimalAt += exponent;
2506 
2507             // If none of the text string was recognized.  For example, parse
2508             // "x" with pattern "#0.00" (return index and error index both 0)
2509             // parse "$" with pattern "$#0.00". (return index 0 and error
2510             // index 1).
2511             if (!sawDigit && digitCount == 0) {
2512                 return -1;
2513             }
2514         }
2515         return position;
2516 
2517     }
2518 
2519     /**
2520      * Returns a copy of the decimal format symbols, which is generally not
2521      * changed by the programmer or user.
2522      * @return a copy of the desired DecimalFormatSymbols
2523      * @see java.text.DecimalFormatSymbols
2524      */
2525     public DecimalFormatSymbols getDecimalFormatSymbols() {
2526         try {
2527             // don't allow multiple references
2528             return (DecimalFormatSymbols) symbols.clone();
2529         } catch (Exception foo) {
2530             return null; // should never happen
2531         }
2532     }
2533 
2534 
2535     /**
2536      * Sets the decimal format symbols, which is generally not changed
2537      * by the programmer or user.
2538      * @param newSymbols desired DecimalFormatSymbols
2539      * @see java.text.DecimalFormatSymbols
2540      */
2541     public void setDecimalFormatSymbols(DecimalFormatSymbols newSymbols) {
2542         try {
2543             // don't allow multiple references
2544             symbols = (DecimalFormatSymbols) newSymbols.clone();
2545             expandAffixes();
2546             fastPathCheckNeeded = true;
2547         } catch (Exception foo) {
2548             // should never happen
2549         }
2550     }
2551 
2552     /**
2553      * Get the positive prefix.
2554      * <P>Examples: +123, $123, sFr123
2555      *
2556      * @return the positive prefix
2557      */
2558     public String getPositivePrefix () {
2559         return positivePrefix;
2560     }
2561 
2562     /**
2563      * Set the positive prefix.
2564      * <P>Examples: +123, $123, sFr123
2565      *
2566      * @param newValue the new positive prefix
2567      */
2568     public void setPositivePrefix (String newValue) {
2569         positivePrefix = newValue;
2570         posPrefixPattern = null;
2571         positivePrefixFieldPositions = null;
2572         fastPathCheckNeeded = true;
2573     }
2574 
2575     /**
2576      * Returns the FieldPositions of the fields in the prefix used for
2577      * positive numbers. This is not used if the user has explicitly set
2578      * a positive prefix via <code>setPositivePrefix</code>. This is
2579      * lazily created.
2580      *
2581      * @return FieldPositions in positive prefix
2582      */
2583     private FieldPosition[] getPositivePrefixFieldPositions() {
2584         if (positivePrefixFieldPositions == null) {
2585             if (posPrefixPattern != null) {
2586                 positivePrefixFieldPositions = expandAffix(posPrefixPattern);
2587             } else {
2588                 positivePrefixFieldPositions = EmptyFieldPositionArray;
2589             }
2590         }
2591         return positivePrefixFieldPositions;
2592     }
2593 
2594     /**
2595      * Get the negative prefix.
2596      * <P>Examples: -123, ($123) (with negative suffix), sFr-123
2597      *
2598      * @return the negative prefix
2599      */
2600     public String getNegativePrefix () {
2601         return negativePrefix;
2602     }
2603 
2604     /**
2605      * Set the negative prefix.
2606      * <P>Examples: -123, ($123) (with negative suffix), sFr-123
2607      *
2608      * @param newValue the new negative prefix
2609      */
2610     public void setNegativePrefix (String newValue) {
2611         negativePrefix = newValue;
2612         negPrefixPattern = null;
2613         fastPathCheckNeeded = true;
2614     }
2615 
2616     /**
2617      * Returns the FieldPositions of the fields in the prefix used for
2618      * negative numbers. This is not used if the user has explicitly set
2619      * a negative prefix via <code>setNegativePrefix</code>. This is
2620      * lazily created.
2621      *
2622      * @return FieldPositions in positive prefix
2623      */
2624     private FieldPosition[] getNegativePrefixFieldPositions() {
2625         if (negativePrefixFieldPositions == null) {
2626             if (negPrefixPattern != null) {
2627                 negativePrefixFieldPositions = expandAffix(negPrefixPattern);
2628             } else {
2629                 negativePrefixFieldPositions = EmptyFieldPositionArray;
2630             }
2631         }
2632         return negativePrefixFieldPositions;
2633     }
2634 
2635     /**
2636      * Get the positive suffix.
2637      * <P>Example: 123%
2638      *
2639      * @return the positive suffix
2640      */
2641     public String getPositiveSuffix () {
2642         return positiveSuffix;
2643     }
2644 
2645     /**
2646      * Set the positive suffix.
2647      * <P>Example: 123%
2648      *
2649      * @param newValue the new positive suffix
2650      */
2651     public void setPositiveSuffix (String newValue) {
2652         positiveSuffix = newValue;
2653         posSuffixPattern = null;
2654         fastPathCheckNeeded = true;
2655     }
2656 
2657     /**
2658      * Returns the FieldPositions of the fields in the suffix used for
2659      * positive numbers. This is not used if the user has explicitly set
2660      * a positive suffix via <code>setPositiveSuffix</code>. This is
2661      * lazily created.
2662      *
2663      * @return FieldPositions in positive prefix
2664      */
2665     private FieldPosition[] getPositiveSuffixFieldPositions() {
2666         if (positiveSuffixFieldPositions == null) {
2667             if (posSuffixPattern != null) {
2668                 positiveSuffixFieldPositions = expandAffix(posSuffixPattern);
2669             } else {
2670                 positiveSuffixFieldPositions = EmptyFieldPositionArray;
2671             }
2672         }
2673         return positiveSuffixFieldPositions;
2674     }
2675 
2676     /**
2677      * Get the negative suffix.
2678      * <P>Examples: -123%, ($123) (with positive suffixes)
2679      *
2680      * @return the negative suffix
2681      */
2682     public String getNegativeSuffix () {
2683         return negativeSuffix;
2684     }
2685 
2686     /**
2687      * Set the negative suffix.
2688      * <P>Examples: 123%
2689      *
2690      * @param newValue the new negative suffix
2691      */
2692     public void setNegativeSuffix (String newValue) {
2693         negativeSuffix = newValue;
2694         negSuffixPattern = null;
2695         fastPathCheckNeeded = true;
2696     }
2697 
2698     /**
2699      * Returns the FieldPositions of the fields in the suffix used for
2700      * negative numbers. This is not used if the user has explicitly set
2701      * a negative suffix via <code>setNegativeSuffix</code>. This is
2702      * lazily created.
2703      *
2704      * @return FieldPositions in positive prefix
2705      */
2706     private FieldPosition[] getNegativeSuffixFieldPositions() {
2707         if (negativeSuffixFieldPositions == null) {
2708             if (negSuffixPattern != null) {
2709                 negativeSuffixFieldPositions = expandAffix(negSuffixPattern);
2710             } else {
2711                 negativeSuffixFieldPositions = EmptyFieldPositionArray;
2712             }
2713         }
2714         return negativeSuffixFieldPositions;
2715     }
2716 
2717     /**
2718      * Gets the multiplier for use in percent, per mille, and similar
2719      * formats.
2720      *
2721      * @return the multiplier
2722      * @see #setMultiplier(int)
2723      */
2724     public int getMultiplier () {
2725         return multiplier;
2726     }
2727 
2728     /**
2729      * Sets the multiplier for use in percent, per mille, and similar
2730      * formats.
2731      * For a percent format, set the multiplier to 100 and the suffixes to
2732      * have '%' (for Arabic, use the Arabic percent sign).
2733      * For a per mille format, set the multiplier to 1000 and the suffixes to
2734      * have '\u2030'.
2735      *
2736      * <P>Example: with multiplier 100, 1.23 is formatted as "123", and
2737      * "123" is parsed into 1.23.
2738      *
2739      * @param newValue the new multiplier
2740      * @see #getMultiplier
2741      */
2742     public void setMultiplier (int newValue) {
2743         multiplier = newValue;
2744         bigDecimalMultiplier = null;
2745         bigIntegerMultiplier = null;
2746         fastPathCheckNeeded = true;
2747     }
2748 
2749     /**
2750      * {@inheritDoc}
2751      */
2752     @Override
2753     public void setGroupingUsed(boolean newValue) {
2754         super.setGroupingUsed(newValue);
2755         fastPathCheckNeeded = true;
2756     }
2757 
2758     /**
2759      * Return the grouping size. Grouping size is the number of digits between
2760      * grouping separators in the integer portion of a number.  For example,
2761      * in the number "123,456.78", the grouping size is 3.
2762      *
2763      * @return the grouping size
2764      * @see #setGroupingSize
2765      * @see java.text.NumberFormat#isGroupingUsed
2766      * @see java.text.DecimalFormatSymbols#getGroupingSeparator
2767      */
2768     public int getGroupingSize () {
2769         return groupingSize;
2770     }
2771 
2772     /**
2773      * Set the grouping size. Grouping size is the number of digits between
2774      * grouping separators in the integer portion of a number.  For example,
2775      * in the number "123,456.78", the grouping size is 3.
2776      * <br>
2777      * The value passed in is converted to a byte, which may lose information.
2778      *
2779      * @param newValue the new grouping size
2780      * @see #getGroupingSize
2781      * @see java.text.NumberFormat#setGroupingUsed
2782      * @see java.text.DecimalFormatSymbols#setGroupingSeparator
2783      */
2784     public void setGroupingSize (int newValue) {
2785         groupingSize = (byte)newValue;
2786         fastPathCheckNeeded = true;
2787     }
2788 
2789     /**
2790      * Allows you to get the behavior of the decimal separator with integers.
2791      * (The decimal separator will always appear with decimals.)
2792      * <P>Example: Decimal ON: 12345 &rarr; 12345.; OFF: 12345 &rarr; 12345
2793      *
2794      * @return {@code true} if the decimal separator is always shown;
2795      *         {@code false} otherwise
2796      */
2797     public boolean isDecimalSeparatorAlwaysShown() {
2798         return decimalSeparatorAlwaysShown;
2799     }
2800 
2801     /**
2802      * Allows you to set the behavior of the decimal separator with integers.
2803      * (The decimal separator will always appear with decimals.)
2804      * <P>Example: Decimal ON: 12345 &rarr; 12345.; OFF: 12345 &rarr; 12345
2805      *
2806      * @param newValue {@code true} if the decimal separator is always shown;
2807      *                 {@code false} otherwise
2808      */
2809     public void setDecimalSeparatorAlwaysShown(boolean newValue) {
2810         decimalSeparatorAlwaysShown = newValue;
2811         fastPathCheckNeeded = true;
2812     }
2813 
2814     /**
2815      * Returns whether the {@link #parse(java.lang.String, java.text.ParsePosition)}
2816      * method returns <code>BigDecimal</code>. The default value is false.
2817      *
2818      * @return {@code true} if the parse method returns BigDecimal;
2819      *         {@code false} otherwise
2820      * @see #setParseBigDecimal
2821      * @since 1.5
2822      */
2823     public boolean isParseBigDecimal() {
2824         return parseBigDecimal;
2825     }
2826 
2827     /**
2828      * Sets whether the {@link #parse(java.lang.String, java.text.ParsePosition)}
2829      * method returns <code>BigDecimal</code>.
2830      *
2831      * @param newValue {@code true} if the parse method returns BigDecimal;
2832      *                 {@code false} otherwise
2833      * @see #isParseBigDecimal
2834      * @since 1.5
2835      */
2836     public void setParseBigDecimal(boolean newValue) {
2837         parseBigDecimal = newValue;
2838     }
2839 
2840     /**
2841      * Standard override; no change in semantics.
2842      */
2843     @Override
2844     public Object clone() {
2845         DecimalFormat other = (DecimalFormat) super.clone();
2846         other.symbols = (DecimalFormatSymbols) symbols.clone();
2847         other.digitList = (DigitList) digitList.clone();
2848 
2849         // Fast-path is almost stateless algorithm. The only logical state is the
2850         // isFastPath flag. In addition fastPathCheckNeeded is a sentinel flag
2851         // that forces recalculation of all fast-path fields when set to true.
2852         //
2853         // There is thus no need to clone all the fast-path fields.
2854         // We just only need to set fastPathCheckNeeded to true when cloning,
2855         // and init fastPathData to null as if it were a truly new instance.
2856         // Every fast-path field will be recalculated (only once) at next usage of
2857         // fast-path algorithm.
2858         other.fastPathCheckNeeded = true;
2859         other.isFastPath = false;
2860         other.fastPathData = null;
2861 
2862         return other;
2863     }
2864 
2865     /**
2866      * Overrides equals
2867      */
2868     @Override
2869     public boolean equals(Object obj)
2870     {
2871         if (obj == null)
2872             return false;
2873         if (!super.equals(obj))
2874             return false; // super does class check
2875         DecimalFormat other = (DecimalFormat) obj;
2876         return ((posPrefixPattern == other.posPrefixPattern &&
2877                  positivePrefix.equals(other.positivePrefix))
2878                 || (posPrefixPattern != null &&
2879                     posPrefixPattern.equals(other.posPrefixPattern)))
2880             && ((posSuffixPattern == other.posSuffixPattern &&
2881                  positiveSuffix.equals(other.positiveSuffix))
2882                 || (posSuffixPattern != null &&
2883                     posSuffixPattern.equals(other.posSuffixPattern)))
2884             && ((negPrefixPattern == other.negPrefixPattern &&
2885                  negativePrefix.equals(other.negativePrefix))
2886                 || (negPrefixPattern != null &&
2887                     negPrefixPattern.equals(other.negPrefixPattern)))
2888             && ((negSuffixPattern == other.negSuffixPattern &&
2889                  negativeSuffix.equals(other.negativeSuffix))
2890                 || (negSuffixPattern != null &&
2891                     negSuffixPattern.equals(other.negSuffixPattern)))
2892             && multiplier == other.multiplier
2893             && groupingSize == other.groupingSize
2894             && decimalSeparatorAlwaysShown == other.decimalSeparatorAlwaysShown
2895             && parseBigDecimal == other.parseBigDecimal
2896             && useExponentialNotation == other.useExponentialNotation
2897             && (!useExponentialNotation ||
2898                 minExponentDigits == other.minExponentDigits)
2899             && maximumIntegerDigits == other.maximumIntegerDigits
2900             && minimumIntegerDigits == other.minimumIntegerDigits
2901             && maximumFractionDigits == other.maximumFractionDigits
2902             && minimumFractionDigits == other.minimumFractionDigits
2903             && roundingMode == other.roundingMode
2904             && symbols.equals(other.symbols);
2905     }
2906 
2907     /**
2908      * Overrides hashCode
2909      */
2910     @Override
2911     public int hashCode() {
2912         return super.hashCode() * 37 + positivePrefix.hashCode();
2913         // just enough fields for a reasonable distribution
2914     }
2915 
2916     /**
2917      * Synthesizes a pattern string that represents the current state
2918      * of this Format object.
2919      *
2920      * @return a pattern string
2921      * @see #applyPattern
2922      */
2923     public String toPattern() {
2924         return toPattern( false );
2925     }
2926 
2927     /**
2928      * Synthesizes a localized pattern string that represents the current
2929      * state of this Format object.
2930      *
2931      * @return a localized pattern string
2932      * @see #applyPattern
2933      */
2934     public String toLocalizedPattern() {
2935         return toPattern( true );
2936     }
2937 
2938     /**
2939      * Expand the affix pattern strings into the expanded affix strings.  If any
2940      * affix pattern string is null, do not expand it.  This method should be
2941      * called any time the symbols or the affix patterns change in order to keep
2942      * the expanded affix strings up to date.
2943      */
2944     private void expandAffixes() {
2945         // Reuse one StringBuffer for better performance
2946         StringBuffer buffer = new StringBuffer();
2947         if (posPrefixPattern != null) {
2948             positivePrefix = expandAffix(posPrefixPattern, buffer);
2949             positivePrefixFieldPositions = null;
2950         }
2951         if (posSuffixPattern != null) {
2952             positiveSuffix = expandAffix(posSuffixPattern, buffer);
2953             positiveSuffixFieldPositions = null;
2954         }
2955         if (negPrefixPattern != null) {
2956             negativePrefix = expandAffix(negPrefixPattern, buffer);
2957             negativePrefixFieldPositions = null;
2958         }
2959         if (negSuffixPattern != null) {
2960             negativeSuffix = expandAffix(negSuffixPattern, buffer);
2961             negativeSuffixFieldPositions = null;
2962         }
2963     }
2964 
2965     /**
2966      * Expand an affix pattern into an affix string.  All characters in the
2967      * pattern are literal unless prefixed by QUOTE.  The following characters
2968      * after QUOTE are recognized: PATTERN_PERCENT, PATTERN_PER_MILLE,
2969      * PATTERN_MINUS, and CURRENCY_SIGN.  If CURRENCY_SIGN is doubled (QUOTE +
2970      * CURRENCY_SIGN + CURRENCY_SIGN), it is interpreted as an ISO 4217
2971      * currency code.  Any other character after a QUOTE represents itself.
2972      * QUOTE must be followed by another character; QUOTE may not occur by
2973      * itself at the end of the pattern.
2974      *
2975      * @param pattern the non-null, possibly empty pattern
2976      * @param buffer a scratch StringBuffer; its contents will be lost
2977      * @return the expanded equivalent of pattern
2978      */
2979     private String expandAffix(String pattern, StringBuffer buffer) {
2980         buffer.setLength(0);
2981         for (int i=0; i<pattern.length(); ) {
2982             char c = pattern.charAt(i++);
2983             if (c == QUOTE) {
2984                 c = pattern.charAt(i++);
2985                 switch (c) {
2986                 case CURRENCY_SIGN:
2987                     if (i<pattern.length() &&
2988                         pattern.charAt(i) == CURRENCY_SIGN) {
2989                         ++i;
2990                         buffer.append(symbols.getInternationalCurrencySymbol());
2991                     } else {
2992                         buffer.append(symbols.getCurrencySymbol());
2993                     }
2994                     continue;
2995                 case PATTERN_PERCENT:
2996                     c = symbols.getPercent();
2997                     break;
2998                 case PATTERN_PER_MILLE:
2999                     c = symbols.getPerMill();
3000                     break;
3001                 case PATTERN_MINUS:
3002                     c = symbols.getMinusSign();
3003                     break;
3004                 }
3005             }
3006             buffer.append(c);
3007         }
3008         return buffer.toString();
3009     }
3010 
3011     /**
3012      * Expand an affix pattern into an array of FieldPositions describing
3013      * how the pattern would be expanded.
3014      * All characters in the
3015      * pattern are literal unless prefixed by QUOTE.  The following characters
3016      * after QUOTE are recognized: PATTERN_PERCENT, PATTERN_PER_MILLE,
3017      * PATTERN_MINUS, and CURRENCY_SIGN.  If CURRENCY_SIGN is doubled (QUOTE +
3018      * CURRENCY_SIGN + CURRENCY_SIGN), it is interpreted as an ISO 4217
3019      * currency code.  Any other character after a QUOTE represents itself.
3020      * QUOTE must be followed by another character; QUOTE may not occur by
3021      * itself at the end of the pattern.
3022      *
3023      * @param pattern the non-null, possibly empty pattern
3024      * @return FieldPosition array of the resulting fields.
3025      */
3026     private FieldPosition[] expandAffix(String pattern) {
3027         ArrayList<FieldPosition> positions = null;
3028         int stringIndex = 0;
3029         for (int i=0; i<pattern.length(); ) {
3030             char c = pattern.charAt(i++);
3031             if (c == QUOTE) {
3032                 int field = -1;
3033                 Format.Field fieldID = null;
3034                 c = pattern.charAt(i++);
3035                 switch (c) {
3036                 case CURRENCY_SIGN:
3037                     String string;
3038                     if (i<pattern.length() &&
3039                         pattern.charAt(i) == CURRENCY_SIGN) {
3040                         ++i;
3041                         string = symbols.getInternationalCurrencySymbol();
3042                     } else {
3043                         string = symbols.getCurrencySymbol();
3044                     }
3045                     if (string.length() > 0) {
3046                         if (positions == null) {
3047                             positions = new ArrayList<>(2);
3048                         }
3049                         FieldPosition fp = new FieldPosition(Field.CURRENCY);
3050                         fp.setBeginIndex(stringIndex);
3051                         fp.setEndIndex(stringIndex + string.length());
3052                         positions.add(fp);
3053                         stringIndex += string.length();
3054                     }
3055                     continue;
3056                 case PATTERN_PERCENT:
3057                     c = symbols.getPercent();
3058                     field = -1;
3059                     fieldID = Field.PERCENT;
3060                     break;
3061                 case PATTERN_PER_MILLE:
3062                     c = symbols.getPerMill();
3063                     field = -1;
3064                     fieldID = Field.PERMILLE;
3065                     break;
3066                 case PATTERN_MINUS:
3067                     c = symbols.getMinusSign();
3068                     field = -1;
3069                     fieldID = Field.SIGN;
3070                     break;
3071                 }
3072                 if (fieldID != null) {
3073                     if (positions == null) {
3074                         positions = new ArrayList<>(2);
3075                     }
3076                     FieldPosition fp = new FieldPosition(fieldID, field);
3077                     fp.setBeginIndex(stringIndex);
3078                     fp.setEndIndex(stringIndex + 1);
3079                     positions.add(fp);
3080                 }
3081             }
3082             stringIndex++;
3083         }
3084         if (positions != null) {
3085             return positions.toArray(EmptyFieldPositionArray);
3086         }
3087         return EmptyFieldPositionArray;
3088     }
3089 
3090     /**
3091      * Appends an affix pattern to the given StringBuffer, quoting special
3092      * characters as needed.  Uses the internal affix pattern, if that exists,
3093      * or the literal affix, if the internal affix pattern is null.  The
3094      * appended string will generate the same affix pattern (or literal affix)
3095      * when passed to toPattern().
3096      *
3097      * @param buffer the affix string is appended to this
3098      * @param affixPattern a pattern such as posPrefixPattern; may be null
3099      * @param expAffix a corresponding expanded affix, such as positivePrefix.
3100      * Ignored unless affixPattern is null.  If affixPattern is null, then
3101      * expAffix is appended as a literal affix.
3102      * @param localized true if the appended pattern should contain localized
3103      * pattern characters; otherwise, non-localized pattern chars are appended
3104      */
3105     private void appendAffix(StringBuffer buffer, String affixPattern,
3106                              String expAffix, boolean localized) {
3107         if (affixPattern == null) {
3108             appendAffix(buffer, expAffix, localized);
3109         } else {
3110             int i;
3111             for (int pos=0; pos<affixPattern.length(); pos=i) {
3112                 i = affixPattern.indexOf(QUOTE, pos);
3113                 if (i < 0) {
3114                     appendAffix(buffer, affixPattern.substring(pos), localized);
3115                     break;
3116                 }
3117                 if (i > pos) {
3118                     appendAffix(buffer, affixPattern.substring(pos, i), localized);
3119                 }
3120                 char c = affixPattern.charAt(++i);
3121                 ++i;
3122                 if (c == QUOTE) {
3123                     buffer.append(c);
3124                     // Fall through and append another QUOTE below
3125                 } else if (c == CURRENCY_SIGN &&
3126                            i<affixPattern.length() &&
3127                            affixPattern.charAt(i) == CURRENCY_SIGN) {
3128                     ++i;
3129                     buffer.append(c);
3130                     // Fall through and append another CURRENCY_SIGN below
3131                 } else if (localized) {
3132                     switch (c) {
3133                     case PATTERN_PERCENT:
3134                         c = symbols.getPercent();
3135                         break;
3136                     case PATTERN_PER_MILLE:
3137                         c = symbols.getPerMill();
3138                         break;
3139                     case PATTERN_MINUS:
3140                         c = symbols.getMinusSign();
3141                         break;
3142                     }
3143                 }
3144                 buffer.append(c);
3145             }
3146         }
3147     }
3148 
3149     /**
3150      * Append an affix to the given StringBuffer, using quotes if
3151      * there are special characters.  Single quotes themselves must be
3152      * escaped in either case.
3153      */
3154     private void appendAffix(StringBuffer buffer, String affix, boolean localized) {
3155         boolean needQuote;
3156         if (localized) {
3157             needQuote = affix.indexOf(symbols.getZeroDigit()) >= 0
3158                 || affix.indexOf(symbols.getGroupingSeparator()) >= 0
3159                 || affix.indexOf(symbols.getDecimalSeparator()) >= 0
3160                 || affix.indexOf(symbols.getPercent()) >= 0
3161                 || affix.indexOf(symbols.getPerMill()) >= 0
3162                 || affix.indexOf(symbols.getDigit()) >= 0
3163                 || affix.indexOf(symbols.getPatternSeparator()) >= 0
3164                 || affix.indexOf(symbols.getMinusSign()) >= 0
3165                 || affix.indexOf(CURRENCY_SIGN) >= 0;
3166         } else {
3167             needQuote = affix.indexOf(PATTERN_ZERO_DIGIT) >= 0
3168                 || affix.indexOf(PATTERN_GROUPING_SEPARATOR) >= 0
3169                 || affix.indexOf(PATTERN_DECIMAL_SEPARATOR) >= 0
3170                 || affix.indexOf(PATTERN_PERCENT) >= 0
3171                 || affix.indexOf(PATTERN_PER_MILLE) >= 0
3172                 || affix.indexOf(PATTERN_DIGIT) >= 0
3173                 || affix.indexOf(PATTERN_SEPARATOR) >= 0
3174                 || affix.indexOf(PATTERN_MINUS) >= 0
3175                 || affix.indexOf(CURRENCY_SIGN) >= 0;
3176         }
3177         if (needQuote) buffer.append('\'');
3178         if (affix.indexOf('\'') < 0) buffer.append(affix);
3179         else {
3180             for (int j=0; j<affix.length(); ++j) {
3181                 char c = affix.charAt(j);
3182                 buffer.append(c);
3183                 if (c == '\'') buffer.append(c);
3184             }
3185         }
3186         if (needQuote) buffer.append('\'');
3187     }
3188 
3189     /**
3190      * Does the real work of generating a pattern.  */
3191     private String toPattern(boolean localized) {
3192         StringBuffer result = new StringBuffer();
3193         for (int j = 1; j >= 0; --j) {
3194             if (j == 1)
3195                 appendAffix(result, posPrefixPattern, positivePrefix, localized);
3196             else appendAffix(result, negPrefixPattern, negativePrefix, localized);
3197             int i;
3198             int digitCount = useExponentialNotation
3199                         ? getMaximumIntegerDigits()
3200                         : Math.max(groupingSize, getMinimumIntegerDigits())+1;
3201             for (i = digitCount; i > 0; --i) {
3202                 if (i != digitCount && isGroupingUsed() && groupingSize != 0 &&
3203                     i % groupingSize == 0) {
3204                     result.append(localized ? symbols.getGroupingSeparator() :
3205                                   PATTERN_GROUPING_SEPARATOR);
3206                 }
3207                 result.append(i <= getMinimumIntegerDigits()
3208                     ? (localized ? symbols.getZeroDigit() : PATTERN_ZERO_DIGIT)
3209                     : (localized ? symbols.getDigit() : PATTERN_DIGIT));
3210             }
3211             if (getMaximumFractionDigits() > 0 || decimalSeparatorAlwaysShown)
3212                 result.append(localized ? symbols.getDecimalSeparator() :
3213                               PATTERN_DECIMAL_SEPARATOR);
3214             for (i = 0; i < getMaximumFractionDigits(); ++i) {
3215                 if (i < getMinimumFractionDigits()) {
3216                     result.append(localized ? symbols.getZeroDigit() :
3217                                   PATTERN_ZERO_DIGIT);
3218                 } else {
3219                     result.append(localized ? symbols.getDigit() :
3220                                   PATTERN_DIGIT);
3221                 }
3222             }
3223         if (useExponentialNotation)
3224         {
3225             result.append(localized ? symbols.getExponentSeparator() :
3226                   PATTERN_EXPONENT);
3227         for (i=0; i<minExponentDigits; ++i)
3228                     result.append(localized ? symbols.getZeroDigit() :
3229                                   PATTERN_ZERO_DIGIT);
3230         }
3231             if (j == 1) {
3232                 appendAffix(result, posSuffixPattern, positiveSuffix, localized);
3233                 if ((negSuffixPattern == posSuffixPattern && // n == p == null
3234                      negativeSuffix.equals(positiveSuffix))
3235                     || (negSuffixPattern != null &&
3236                         negSuffixPattern.equals(posSuffixPattern))) {
3237                     if ((negPrefixPattern != null && posPrefixPattern != null &&
3238                          negPrefixPattern.equals("'-" + posPrefixPattern)) ||
3239                         (negPrefixPattern == posPrefixPattern && // n == p == null
3240                          negativePrefix.equals(symbols.getMinusSign() + positivePrefix)))
3241                         break;
3242                 }
3243                 result.append(localized ? symbols.getPatternSeparator() :
3244                               PATTERN_SEPARATOR);
3245             } else appendAffix(result, negSuffixPattern, negativeSuffix, localized);
3246         }
3247         return result.toString();
3248     }
3249 
3250     /**
3251      * Apply the given pattern to this Format object.  A pattern is a
3252      * short-hand specification for the various formatting properties.
3253      * These properties can also be changed individually through the
3254      * various setter methods.
3255      * <p>
3256      * There is no limit to integer digits set
3257      * by this routine, since that is the typical end-user desire;
3258      * use setMaximumInteger if you want to set a real value.
3259      * For negative numbers, use a second pattern, separated by a semicolon
3260      * <P>Example <code>"#,#00.0#"</code> &rarr; 1,234.56
3261      * <P>This means a minimum of 2 integer digits, 1 fraction digit, and
3262      * a maximum of 2 fraction digits.
3263      * <p>Example: <code>"#,#00.0#;(#,#00.0#)"</code> for negatives in
3264      * parentheses.
3265      * <p>In negative patterns, the minimum and maximum counts are ignored;
3266      * these are presumed to be set in the positive pattern.
3267      *
3268      * @param pattern a new pattern
3269      * @exception NullPointerException if <code>pattern</code> is null
3270      * @exception IllegalArgumentException if the given pattern is invalid.
3271      */
3272     public void applyPattern(String pattern) {
3273         applyPattern(pattern, false);
3274     }
3275 
3276     /**
3277      * Apply the given pattern to this Format object.  The pattern
3278      * is assumed to be in a localized notation. A pattern is a
3279      * short-hand specification for the various formatting properties.
3280      * These properties can also be changed individually through the
3281      * various setter methods.
3282      * <p>
3283      * There is no limit to integer digits set
3284      * by this routine, since that is the typical end-user desire;
3285      * use setMaximumInteger if you want to set a real value.
3286      * For negative numbers, use a second pattern, separated by a semicolon
3287      * <P>Example <code>"#,#00.0#"</code> &rarr; 1,234.56
3288      * <P>This means a minimum of 2 integer digits, 1 fraction digit, and
3289      * a maximum of 2 fraction digits.
3290      * <p>Example: <code>"#,#00.0#;(#,#00.0#)"</code> for negatives in
3291      * parentheses.
3292      * <p>In negative patterns, the minimum and maximum counts are ignored;
3293      * these are presumed to be set in the positive pattern.
3294      *
3295      * @param pattern a new pattern
3296      * @exception NullPointerException if <code>pattern</code> is null
3297      * @exception IllegalArgumentException if the given pattern is invalid.
3298      */
3299     public void applyLocalizedPattern(String pattern) {
3300         applyPattern(pattern, true);
3301     }
3302 
3303     /**
3304      * Does the real work of applying a pattern.
3305      */
3306     private void applyPattern(String pattern, boolean localized) {
3307         char zeroDigit         = PATTERN_ZERO_DIGIT;
3308         char groupingSeparator = PATTERN_GROUPING_SEPARATOR;
3309         char decimalSeparator  = PATTERN_DECIMAL_SEPARATOR;
3310         char percent           = PATTERN_PERCENT;
3311         char perMill           = PATTERN_PER_MILLE;
3312         char digit             = PATTERN_DIGIT;
3313         char separator         = PATTERN_SEPARATOR;
3314         String exponent          = PATTERN_EXPONENT;
3315         char minus             = PATTERN_MINUS;
3316         if (localized) {
3317             zeroDigit         = symbols.getZeroDigit();
3318             groupingSeparator = symbols.getGroupingSeparator();
3319             decimalSeparator  = symbols.getDecimalSeparator();
3320             percent           = symbols.getPercent();
3321             perMill           = symbols.getPerMill();
3322             digit             = symbols.getDigit();
3323             separator         = symbols.getPatternSeparator();
3324             exponent          = symbols.getExponentSeparator();
3325             minus             = symbols.getMinusSign();
3326         }
3327         boolean gotNegative = false;
3328         decimalSeparatorAlwaysShown = false;
3329         isCurrencyFormat = false;
3330         useExponentialNotation = false;
3331 
3332         int start = 0;
3333         for (int j = 1; j >= 0 && start < pattern.length(); --j) {
3334             boolean inQuote = false;
3335             StringBuffer prefix = new StringBuffer();
3336             StringBuffer suffix = new StringBuffer();
3337             int decimalPos = -1;
3338             int multiplier = 1;
3339             int digitLeftCount = 0, zeroDigitCount = 0, digitRightCount = 0;
3340             byte groupingCount = -1;
3341 
3342             // The phase ranges from 0 to 2.  Phase 0 is the prefix.  Phase 1 is
3343             // the section of the pattern with digits, decimal separator,
3344             // grouping characters.  Phase 2 is the suffix.  In phases 0 and 2,
3345             // percent, per mille, and currency symbols are recognized and
3346             // translated.  The separation of the characters into phases is
3347             // strictly enforced; if phase 1 characters are to appear in the
3348             // suffix, for example, they must be quoted.
3349             int phase = 0;
3350 
3351             // The affix is either the prefix or the suffix.
3352             StringBuffer affix = prefix;
3353 
3354             for (int pos = start; pos < pattern.length(); ++pos) {
3355                 char ch = pattern.charAt(pos);
3356                 switch (phase) {
3357                 case 0:
3358                 case 2:
3359                     // Process the prefix / suffix characters
3360                     if (inQuote) {
3361                         // A quote within quotes indicates either the closing
3362                         // quote or two quotes, which is a quote literal. That
3363                         // is, we have the second quote in 'do' or 'don''t'.
3364                         if (ch == QUOTE) {
3365                             if ((pos+1) < pattern.length() &&
3366                                 pattern.charAt(pos+1) == QUOTE) {
3367                                 ++pos;
3368                                 affix.append("''"); // 'don''t'
3369                             } else {
3370                                 inQuote = false; // 'do'
3371                             }
3372                             continue;
3373                         }
3374                     } else {
3375                         // Process unquoted characters seen in prefix or suffix
3376                         // phase.
3377                         if (ch == digit ||
3378                             ch == zeroDigit ||
3379                             ch == groupingSeparator ||
3380                             ch == decimalSeparator) {
3381                             phase = 1;
3382                             --pos; // Reprocess this character
3383                             continue;
3384                         } else if (ch == CURRENCY_SIGN) {
3385                             // Use lookahead to determine if the currency sign
3386                             // is doubled or not.
3387                             boolean doubled = (pos + 1) < pattern.length() &&
3388                                 pattern.charAt(pos + 1) == CURRENCY_SIGN;
3389                             if (doubled) { // Skip over the doubled character
3390                              ++pos;
3391                             }
3392                             isCurrencyFormat = true;
3393                             affix.append(doubled ? "'\u00A4\u00A4" : "'\u00A4");
3394                             continue;
3395                         } else if (ch == QUOTE) {
3396                             // A quote outside quotes indicates either the
3397                             // opening quote or two quotes, which is a quote
3398                             // literal. That is, we have the first quote in 'do'
3399                             // or o''clock.
3400                             if (ch == QUOTE) {
3401                                 if ((pos+1) < pattern.length() &&
3402                                     pattern.charAt(pos+1) == QUOTE) {
3403                                     ++pos;
3404                                     affix.append("''"); // o''clock
3405                                 } else {
3406                                     inQuote = true; // 'do'
3407                                 }
3408                                 continue;
3409                             }
3410                         } else if (ch == separator) {
3411                             // Don't allow separators before we see digit
3412                             // characters of phase 1, and don't allow separators
3413                             // in the second pattern (j == 0).
3414                             if (phase == 0 || j == 0) {
3415                                 throw new IllegalArgumentException("Unquoted special character '" +
3416                                     ch + "' in pattern \"" + pattern + '"');
3417                             }
3418                             start = pos + 1;
3419                             pos = pattern.length();
3420                             continue;
3421                         }
3422 
3423                         // Next handle characters which are appended directly.
3424                         else if (ch == percent) {
3425                             if (multiplier != 1) {
3426                                 throw new IllegalArgumentException("Too many percent/per mille characters in pattern \"" +
3427                                     pattern + '"');
3428                             }
3429                             multiplier = 100;
3430                             affix.append("'%");
3431                             continue;
3432                         } else if (ch == perMill) {
3433                             if (multiplier != 1) {
3434                                 throw new IllegalArgumentException("Too many percent/per mille characters in pattern \"" +
3435                                     pattern + '"');
3436                             }
3437                             multiplier = 1000;
3438                             affix.append("'\u2030");
3439                             continue;
3440                         } else if (ch == minus) {
3441                             affix.append("'-");
3442                             continue;
3443                         }
3444                     }
3445                     // Note that if we are within quotes, or if this is an
3446                     // unquoted, non-special character, then we usually fall
3447                     // through to here.
3448                     affix.append(ch);
3449                     break;
3450 
3451                 case 1:
3452                     // The negative subpattern (j = 0) serves only to specify the
3453                     // negative prefix and suffix, so all the phase 1 characters
3454                     // e.g. digits, zeroDigit, groupingSeparator,
3455                     // decimalSeparator, exponent are ignored
3456                     if (j == 0) {
3457                         while (pos < pattern.length()) {
3458                             char negPatternChar = pattern.charAt(pos);
3459                             if (negPatternChar == digit
3460                                     || negPatternChar == zeroDigit
3461                                     || negPatternChar == groupingSeparator
3462                                     || negPatternChar == decimalSeparator) {
3463                                 ++pos;
3464                             } else if (pattern.regionMatches(pos, exponent,
3465                                     0, exponent.length())) {
3466                                 pos = pos + exponent.length();
3467                             } else {
3468                                 // Not a phase 1 character, consider it as
3469                                 // suffix and parse it in phase 2
3470                                 --pos; //process it again in outer loop
3471                                 phase = 2;
3472                                 affix = suffix;
3473                                 break;
3474                             }
3475                         }
3476                         continue;
3477                     }
3478 
3479                     // Process the digits, decimal, and grouping characters. We
3480                     // record five pieces of information. We expect the digits
3481                     // to occur in the pattern ####0000.####, and we record the
3482                     // number of left digits, zero (central) digits, and right
3483                     // digits. The position of the last grouping character is
3484                     // recorded (should be somewhere within the first two blocks
3485                     // of characters), as is the position of the decimal point,
3486                     // if any (should be in the zero digits). If there is no
3487                     // decimal point, then there should be no right digits.
3488                     if (ch == digit) {
3489                         if (zeroDigitCount > 0) {
3490                             ++digitRightCount;
3491                         } else {
3492                             ++digitLeftCount;
3493                         }
3494                         if (groupingCount >= 0 && decimalPos < 0) {
3495                             ++groupingCount;
3496                         }
3497                     } else if (ch == zeroDigit) {
3498                         if (digitRightCount > 0) {
3499                             throw new IllegalArgumentException("Unexpected '0' in pattern \"" +
3500                                 pattern + '"');
3501                         }
3502                         ++zeroDigitCount;
3503                         if (groupingCount >= 0 && decimalPos < 0) {
3504                             ++groupingCount;
3505                         }
3506                     } else if (ch == groupingSeparator) {
3507                         groupingCount = 0;
3508                     } else if (ch == decimalSeparator) {
3509                         if (decimalPos >= 0) {
3510                             throw new IllegalArgumentException("Multiple decimal separators in pattern \"" +
3511                                 pattern + '"');
3512                         }
3513                         decimalPos = digitLeftCount + zeroDigitCount + digitRightCount;
3514                     } else if (pattern.regionMatches(pos, exponent, 0, exponent.length())){
3515                         if (useExponentialNotation) {
3516                             throw new IllegalArgumentException("Multiple exponential " +
3517                                 "symbols in pattern \"" + pattern + '"');
3518                         }
3519                         useExponentialNotation = true;
3520                         minExponentDigits = 0;
3521 
3522                         // Use lookahead to parse out the exponential part
3523                         // of the pattern, then jump into phase 2.
3524                         pos = pos+exponent.length();
3525                          while (pos < pattern.length() &&
3526                                pattern.charAt(pos) == zeroDigit) {
3527                             ++minExponentDigits;
3528                             ++pos;
3529                         }
3530 
3531                         if ((digitLeftCount + zeroDigitCount) < 1 ||
3532                             minExponentDigits < 1) {
3533                             throw new IllegalArgumentException("Malformed exponential " +
3534                                 "pattern \"" + pattern + '"');
3535                         }
3536 
3537                         // Transition to phase 2
3538                         phase = 2;
3539                         affix = suffix;
3540                         --pos;
3541                         continue;
3542                     } else {
3543                         phase = 2;
3544                         affix = suffix;
3545                         --pos;
3546                         continue;
3547                     }
3548                     break;
3549                 }
3550             }
3551 
3552             // Handle patterns with no '0' pattern character. These patterns
3553             // are legal, but must be interpreted.  "##.###" -> "#0.###".
3554             // ".###" -> ".0##".
3555             /* We allow patterns of the form "####" to produce a zeroDigitCount
3556              * of zero (got that?); although this seems like it might make it
3557              * possible for format() to produce empty strings, format() checks
3558              * for this condition and outputs a zero digit in this situation.
3559              * Having a zeroDigitCount of zero yields a minimum integer digits
3560              * of zero, which allows proper round-trip patterns.  That is, we
3561              * don't want "#" to become "#0" when toPattern() is called (even
3562              * though that's what it really is, semantically).
3563              */
3564             if (zeroDigitCount == 0 && digitLeftCount > 0 && decimalPos >= 0) {
3565                 // Handle "###.###" and "###." and ".###"
3566                 int n = decimalPos;
3567                 if (n == 0) { // Handle ".###"
3568                     ++n;
3569                 }
3570                 digitRightCount = digitLeftCount - n;
3571                 digitLeftCount = n - 1;
3572                 zeroDigitCount = 1;
3573             }
3574 
3575             // Do syntax checking on the digits.
3576             if ((decimalPos < 0 && digitRightCount > 0) ||
3577                 (decimalPos >= 0 && (decimalPos < digitLeftCount ||
3578                  decimalPos > (digitLeftCount + zeroDigitCount))) ||
3579                  groupingCount == 0 || inQuote) {
3580                 throw new IllegalArgumentException("Malformed pattern \"" +
3581                     pattern + '"');
3582             }
3583 
3584             if (j == 1) {
3585                 posPrefixPattern = prefix.toString();
3586                 posSuffixPattern = suffix.toString();
3587                 negPrefixPattern = posPrefixPattern;   // assume these for now
3588                 negSuffixPattern = posSuffixPattern;
3589                 int digitTotalCount = digitLeftCount + zeroDigitCount + digitRightCount;
3590                 /* The effectiveDecimalPos is the position the decimal is at or
3591                  * would be at if there is no decimal. Note that if decimalPos<0,
3592                  * then digitTotalCount == digitLeftCount + zeroDigitCount.
3593                  */
3594                 int effectiveDecimalPos = decimalPos >= 0 ?
3595                     decimalPos : digitTotalCount;
3596                 setMinimumIntegerDigits(effectiveDecimalPos - digitLeftCount);
3597                 setMaximumIntegerDigits(useExponentialNotation ?
3598                     digitLeftCount + getMinimumIntegerDigits() :
3599                     MAXIMUM_INTEGER_DIGITS);
3600                 setMaximumFractionDigits(decimalPos >= 0 ?
3601                     (digitTotalCount - decimalPos) : 0);
3602                 setMinimumFractionDigits(decimalPos >= 0 ?
3603                     (digitLeftCount + zeroDigitCount - decimalPos) : 0);
3604                 setGroupingUsed(groupingCount > 0);
3605                 this.groupingSize = (groupingCount > 0) ? groupingCount : 0;
3606                 this.multiplier = multiplier;
3607                 setDecimalSeparatorAlwaysShown(decimalPos == 0 ||
3608                     decimalPos == digitTotalCount);
3609             } else {
3610                 negPrefixPattern = prefix.toString();
3611                 negSuffixPattern = suffix.toString();
3612                 gotNegative = true;
3613             }
3614         }
3615 
3616         if (pattern.length() == 0) {
3617             posPrefixPattern = posSuffixPattern = "";
3618             setMinimumIntegerDigits(0);
3619             setMaximumIntegerDigits(MAXIMUM_INTEGER_DIGITS);
3620             setMinimumFractionDigits(0);
3621             setMaximumFractionDigits(MAXIMUM_FRACTION_DIGITS);
3622         }
3623 
3624         // If there was no negative pattern, or if the negative pattern is
3625         // identical to the positive pattern, then prepend the minus sign to
3626         // the positive pattern to form the negative pattern.
3627         if (!gotNegative ||
3628             (negPrefixPattern.equals(posPrefixPattern)
3629              && negSuffixPattern.equals(posSuffixPattern))) {
3630             negSuffixPattern = posSuffixPattern;
3631             negPrefixPattern = "'-" + posPrefixPattern;
3632         }
3633 
3634         expandAffixes();
3635     }
3636 
3637     /**
3638      * Sets the maximum number of digits allowed in the integer portion of a
3639      * number.
3640      * For formatting numbers other than <code>BigInteger</code> and
3641      * <code>BigDecimal</code> objects, the lower of <code>newValue</code> and
3642      * 309 is used. Negative input values are replaced with 0.
3643      * @see NumberFormat#setMaximumIntegerDigits
3644      */
3645     @Override
3646     public void setMaximumIntegerDigits(int newValue) {
3647         maximumIntegerDigits = Math.min(Math.max(0, newValue), MAXIMUM_INTEGER_DIGITS);
3648         super.setMaximumIntegerDigits((maximumIntegerDigits > DOUBLE_INTEGER_DIGITS) ?
3649             DOUBLE_INTEGER_DIGITS : maximumIntegerDigits);
3650         if (minimumIntegerDigits > maximumIntegerDigits) {
3651             minimumIntegerDigits = maximumIntegerDigits;
3652             super.setMinimumIntegerDigits((minimumIntegerDigits > DOUBLE_INTEGER_DIGITS) ?
3653                 DOUBLE_INTEGER_DIGITS : minimumIntegerDigits);
3654         }
3655         fastPathCheckNeeded = true;
3656     }
3657 
3658     /**
3659      * Sets the minimum number of digits allowed in the integer portion of a
3660      * number.
3661      * For formatting numbers other than <code>BigInteger</code> and
3662      * <code>BigDecimal</code> objects, the lower of <code>newValue</code> and
3663      * 309 is used. Negative input values are replaced with 0.
3664      * @see NumberFormat#setMinimumIntegerDigits
3665      */
3666     @Override
3667     public void setMinimumIntegerDigits(int newValue) {
3668         minimumIntegerDigits = Math.min(Math.max(0, newValue), MAXIMUM_INTEGER_DIGITS);
3669         super.setMinimumIntegerDigits((minimumIntegerDigits > DOUBLE_INTEGER_DIGITS) ?
3670             DOUBLE_INTEGER_DIGITS : minimumIntegerDigits);
3671         if (minimumIntegerDigits > maximumIntegerDigits) {
3672             maximumIntegerDigits = minimumIntegerDigits;
3673             super.setMaximumIntegerDigits((maximumIntegerDigits > DOUBLE_INTEGER_DIGITS) ?
3674                 DOUBLE_INTEGER_DIGITS : maximumIntegerDigits);
3675         }
3676         fastPathCheckNeeded = true;
3677     }
3678 
3679     /**
3680      * Sets the maximum number of digits allowed in the fraction portion of a
3681      * number.
3682      * For formatting numbers other than <code>BigInteger</code> and
3683      * <code>BigDecimal</code> objects, the lower of <code>newValue</code> and
3684      * 340 is used. Negative input values are replaced with 0.
3685      * @see NumberFormat#setMaximumFractionDigits
3686      */
3687     @Override
3688     public void setMaximumFractionDigits(int newValue) {
3689         maximumFractionDigits = Math.min(Math.max(0, newValue), MAXIMUM_FRACTION_DIGITS);
3690         super.setMaximumFractionDigits((maximumFractionDigits > DOUBLE_FRACTION_DIGITS) ?
3691             DOUBLE_FRACTION_DIGITS : maximumFractionDigits);
3692         if (minimumFractionDigits > maximumFractionDigits) {
3693             minimumFractionDigits = maximumFractionDigits;
3694             super.setMinimumFractionDigits((minimumFractionDigits > DOUBLE_FRACTION_DIGITS) ?
3695                 DOUBLE_FRACTION_DIGITS : minimumFractionDigits);
3696         }
3697         fastPathCheckNeeded = true;
3698     }
3699 
3700     /**
3701      * Sets the minimum number of digits allowed in the fraction portion of a
3702      * number.
3703      * For formatting numbers other than <code>BigInteger</code> and
3704      * <code>BigDecimal</code> objects, the lower of <code>newValue</code> and
3705      * 340 is used. Negative input values are replaced with 0.
3706      * @see NumberFormat#setMinimumFractionDigits
3707      */
3708     @Override
3709     public void setMinimumFractionDigits(int newValue) {
3710         minimumFractionDigits = Math.min(Math.max(0, newValue), MAXIMUM_FRACTION_DIGITS);
3711         super.setMinimumFractionDigits((minimumFractionDigits > DOUBLE_FRACTION_DIGITS) ?
3712             DOUBLE_FRACTION_DIGITS : minimumFractionDigits);
3713         if (minimumFractionDigits > maximumFractionDigits) {
3714             maximumFractionDigits = minimumFractionDigits;
3715             super.setMaximumFractionDigits((maximumFractionDigits > DOUBLE_FRACTION_DIGITS) ?
3716                 DOUBLE_FRACTION_DIGITS : maximumFractionDigits);
3717         }
3718         fastPathCheckNeeded = true;
3719     }
3720 
3721     /**
3722      * Gets the maximum number of digits allowed in the integer portion of a
3723      * number.
3724      * For formatting numbers other than <code>BigInteger</code> and
3725      * <code>BigDecimal</code> objects, the lower of the return value and
3726      * 309 is used.
3727      * @see #setMaximumIntegerDigits
3728      */
3729     @Override
3730     public int getMaximumIntegerDigits() {
3731         return maximumIntegerDigits;
3732     }
3733 
3734     /**
3735      * Gets the minimum number of digits allowed in the integer portion of a
3736      * number.
3737      * For formatting numbers other than <code>BigInteger</code> and
3738      * <code>BigDecimal</code> objects, the lower of the return value and
3739      * 309 is used.
3740      * @see #setMinimumIntegerDigits
3741      */
3742     @Override
3743     public int getMinimumIntegerDigits() {
3744         return minimumIntegerDigits;
3745     }
3746 
3747     /**
3748      * Gets the maximum number of digits allowed in the fraction portion of a
3749      * number.
3750      * For formatting numbers other than <code>BigInteger</code> and
3751      * <code>BigDecimal</code> objects, the lower of the return value and
3752      * 340 is used.
3753      * @see #setMaximumFractionDigits
3754      */
3755     @Override
3756     public int getMaximumFractionDigits() {
3757         return maximumFractionDigits;
3758     }
3759 
3760     /**
3761      * Gets the minimum number of digits allowed in the fraction portion of a
3762      * number.
3763      * For formatting numbers other than <code>BigInteger</code> and
3764      * <code>BigDecimal</code> objects, the lower of the return value and
3765      * 340 is used.
3766      * @see #setMinimumFractionDigits
3767      */
3768     @Override
3769     public int getMinimumFractionDigits() {
3770         return minimumFractionDigits;
3771     }
3772 
3773     /**
3774      * Gets the currency used by this decimal format when formatting
3775      * currency values.
3776      * The currency is obtained by calling
3777      * {@link DecimalFormatSymbols#getCurrency DecimalFormatSymbols.getCurrency}
3778      * on this number format's symbols.
3779      *
3780      * @return the currency used by this decimal format, or <code>null</code>
3781      * @since 1.4
3782      */
3783     @Override
3784     public Currency getCurrency() {
3785         return symbols.getCurrency();
3786     }
3787 
3788     /**
3789      * Sets the currency used by this number format when formatting
3790      * currency values. This does not update the minimum or maximum
3791      * number of fraction digits used by the number format.
3792      * The currency is set by calling
3793      * {@link DecimalFormatSymbols#setCurrency DecimalFormatSymbols.setCurrency}
3794      * on this number format's symbols.
3795      *
3796      * @param currency the new currency to be used by this decimal format
3797      * @exception NullPointerException if <code>currency</code> is null
3798      * @since 1.4
3799      */
3800     @Override
3801     public void setCurrency(Currency currency) {
3802         if (currency != symbols.getCurrency()) {
3803             symbols.setCurrency(currency);
3804             if (isCurrencyFormat) {
3805                 expandAffixes();
3806             }
3807         }
3808         fastPathCheckNeeded = true;
3809     }
3810 
3811     /**
3812      * Gets the {@link java.math.RoundingMode} used in this DecimalFormat.
3813      *
3814      * @return The <code>RoundingMode</code> used for this DecimalFormat.
3815      * @see #setRoundingMode(RoundingMode)
3816      * @since 1.6
3817      */
3818     @Override
3819     public RoundingMode getRoundingMode() {
3820         return roundingMode;
3821     }
3822 
3823     /**
3824      * Sets the {@link java.math.RoundingMode} used in this DecimalFormat.
3825      *
3826      * @param roundingMode The <code>RoundingMode</code> to be used
3827      * @see #getRoundingMode()
3828      * @exception NullPointerException if <code>roundingMode</code> is null.
3829      * @since 1.6
3830      */
3831     @Override
3832     public void setRoundingMode(RoundingMode roundingMode) {
3833         if (roundingMode == null) {
3834             throw new NullPointerException();
3835         }
3836 
3837         this.roundingMode = roundingMode;
3838         digitList.setRoundingMode(roundingMode);
3839         fastPathCheckNeeded = true;
3840     }
3841 
3842     /**
3843      * Reads the default serializable fields from the stream and performs
3844      * validations and adjustments for older serialized versions. The
3845      * validations and adjustments are:
3846      * <ol>
3847      * <li>
3848      * Verify that the superclass's digit count fields correctly reflect
3849      * the limits imposed on formatting numbers other than
3850      * <code>BigInteger</code> and <code>BigDecimal</code> objects. These
3851      * limits are stored in the superclass for serialization compatibility
3852      * with older versions, while the limits for <code>BigInteger</code> and
3853      * <code>BigDecimal</code> objects are kept in this class.
3854      * If, in the superclass, the minimum or maximum integer digit count is
3855      * larger than <code>DOUBLE_INTEGER_DIGITS</code> or if the minimum or
3856      * maximum fraction digit count is larger than
3857      * <code>DOUBLE_FRACTION_DIGITS</code>, then the stream data is invalid
3858      * and this method throws an <code>InvalidObjectException</code>.
3859      * <li>
3860      * If <code>serialVersionOnStream</code> is less than 4, initialize
3861      * <code>roundingMode</code> to {@link java.math.RoundingMode#HALF_EVEN
3862      * RoundingMode.HALF_EVEN}.  This field is new with version 4.
3863      * <li>
3864      * If <code>serialVersionOnStream</code> is less than 3, then call
3865      * the setters for the minimum and maximum integer and fraction digits with
3866      * the values of the corresponding superclass getters to initialize the
3867      * fields in this class. The fields in this class are new with version 3.
3868      * <li>
3869      * If <code>serialVersionOnStream</code> is less than 1, indicating that
3870      * the stream was written by JDK 1.1, initialize
3871      * <code>useExponentialNotation</code>
3872      * to false, since it was not present in JDK 1.1.
3873      * <li>
3874      * Set <code>serialVersionOnStream</code> to the maximum allowed value so
3875      * that default serialization will work properly if this object is streamed
3876      * out again.
3877      * </ol>
3878      *
3879      * <p>Stream versions older than 2 will not have the affix pattern variables
3880      * <code>posPrefixPattern</code> etc.  As a result, they will be initialized
3881      * to <code>null</code>, which means the affix strings will be taken as
3882      * literal values.  This is exactly what we want, since that corresponds to
3883      * the pre-version-2 behavior.
3884      */
3885     private void readObject(ObjectInputStream stream)
3886          throws IOException, ClassNotFoundException
3887     {
3888         stream.defaultReadObject();
3889         digitList = new DigitList();
3890 
3891         // We force complete fast-path reinitialization when the instance is
3892         // deserialized. See clone() comment on fastPathCheckNeeded.
3893         fastPathCheckNeeded = true;
3894         isFastPath = false;
3895         fastPathData = null;
3896 
3897         if (serialVersionOnStream < 4) {
3898             setRoundingMode(RoundingMode.HALF_EVEN);
3899         } else {
3900             setRoundingMode(getRoundingMode());
3901         }
3902 
3903         // We only need to check the maximum counts because NumberFormat
3904         // .readObject has already ensured that the maximum is greater than the
3905         // minimum count.
3906         if (super.getMaximumIntegerDigits() > DOUBLE_INTEGER_DIGITS ||
3907             super.getMaximumFractionDigits() > DOUBLE_FRACTION_DIGITS) {
3908             throw new InvalidObjectException("Digit count out of range");
3909         }
3910         if (serialVersionOnStream < 3) {
3911             setMaximumIntegerDigits(super.getMaximumIntegerDigits());
3912             setMinimumIntegerDigits(super.getMinimumIntegerDigits());
3913             setMaximumFractionDigits(super.getMaximumFractionDigits());
3914             setMinimumFractionDigits(super.getMinimumFractionDigits());
3915         }
3916         if (serialVersionOnStream < 1) {
3917             // Didn't have exponential fields
3918             useExponentialNotation = false;
3919         }
3920         serialVersionOnStream = currentSerialVersion;
3921     }
3922 
3923     //----------------------------------------------------------------------
3924     // INSTANCE VARIABLES
3925     //----------------------------------------------------------------------
3926 
3927     private transient DigitList digitList = new DigitList();
3928 
3929     /**
3930      * The symbol used as a prefix when formatting positive numbers, e.g. "+".
3931      *
3932      * @serial
3933      * @see #getPositivePrefix
3934      */
3935     private String  positivePrefix = "";
3936 
3937     /**
3938      * The symbol used as a suffix when formatting positive numbers.
3939      * This is often an empty string.
3940      *
3941      * @serial
3942      * @see #getPositiveSuffix
3943      */
3944     private String  positiveSuffix = "";
3945 
3946     /**
3947      * The symbol used as a prefix when formatting negative numbers, e.g. "-".
3948      *
3949      * @serial
3950      * @see #getNegativePrefix
3951      */
3952     private String  negativePrefix = "-";
3953 
3954     /**
3955      * The symbol used as a suffix when formatting negative numbers.
3956      * This is often an empty string.
3957      *
3958      * @serial
3959      * @see #getNegativeSuffix
3960      */
3961     private String  negativeSuffix = "";
3962 
3963     /**
3964      * The prefix pattern for non-negative numbers.  This variable corresponds
3965      * to <code>positivePrefix</code>.
3966      *
3967      * <p>This pattern is expanded by the method <code>expandAffix()</code> to
3968      * <code>positivePrefix</code> to update the latter to reflect changes in
3969      * <code>symbols</code>.  If this variable is <code>null</code> then
3970      * <code>positivePrefix</code> is taken as a literal value that does not
3971      * change when <code>symbols</code> changes.  This variable is always
3972      * <code>null</code> for <code>DecimalFormat</code> objects older than
3973      * stream version 2 restored from stream.
3974      *
3975      * @serial
3976      * @since 1.3
3977      */
3978     private String posPrefixPattern;
3979 
3980     /**
3981      * The suffix pattern for non-negative numbers.  This variable corresponds
3982      * to <code>positiveSuffix</code>.  This variable is analogous to
3983      * <code>posPrefixPattern</code>; see that variable for further
3984      * documentation.
3985      *
3986      * @serial
3987      * @since 1.3
3988      */
3989     private String posSuffixPattern;
3990 
3991     /**
3992      * The prefix pattern for negative numbers.  This variable corresponds
3993      * to <code>negativePrefix</code>.  This variable is analogous to
3994      * <code>posPrefixPattern</code>; see that variable for further
3995      * documentation.
3996      *
3997      * @serial
3998      * @since 1.3
3999      */
4000     private String negPrefixPattern;
4001 
4002     /**
4003      * The suffix pattern for negative numbers.  This variable corresponds
4004      * to <code>negativeSuffix</code>.  This variable is analogous to
4005      * <code>posPrefixPattern</code>; see that variable for further
4006      * documentation.
4007      *
4008      * @serial
4009      * @since 1.3
4010      */
4011     private String negSuffixPattern;
4012 
4013     /**
4014      * The multiplier for use in percent, per mille, etc.
4015      *
4016      * @serial
4017      * @see #getMultiplier
4018      */
4019     private int     multiplier = 1;
4020 
4021     /**
4022      * The number of digits between grouping separators in the integer
4023      * portion of a number.  Must be greater than 0 if
4024      * <code>NumberFormat.groupingUsed</code> is true.
4025      *
4026      * @serial
4027      * @see #getGroupingSize
4028      * @see java.text.NumberFormat#isGroupingUsed
4029      */
4030     private byte    groupingSize = 3;  // invariant, > 0 if useThousands
4031 
4032     /**
4033      * If true, forces the decimal separator to always appear in a formatted
4034      * number, even if the fractional part of the number is zero.
4035      *
4036      * @serial
4037      * @see #isDecimalSeparatorAlwaysShown
4038      */
4039     private boolean decimalSeparatorAlwaysShown = false;
4040 
4041     /**
4042      * If true, parse returns BigDecimal wherever possible.
4043      *
4044      * @serial
4045      * @see #isParseBigDecimal
4046      * @since 1.5
4047      */
4048     private boolean parseBigDecimal = false;
4049 
4050 
4051     /**
4052      * True if this object represents a currency format.  This determines
4053      * whether the monetary decimal separator is used instead of the normal one.
4054      */
4055     private transient boolean isCurrencyFormat = false;
4056 
4057     /**
4058      * The <code>DecimalFormatSymbols</code> object used by this format.
4059      * It contains the symbols used to format numbers, e.g. the grouping separator,
4060      * decimal separator, and so on.
4061      *
4062      * @serial
4063      * @see #setDecimalFormatSymbols
4064      * @see java.text.DecimalFormatSymbols
4065      */
4066     private DecimalFormatSymbols symbols = null; // LIU new DecimalFormatSymbols();
4067 
4068     /**
4069      * True to force the use of exponential (i.e. scientific) notation when formatting
4070      * numbers.
4071      *
4072      * @serial
4073      * @since 1.2
4074      */
4075     private boolean useExponentialNotation;  // Newly persistent in the Java 2 platform v.1.2
4076 
4077     /**
4078      * FieldPositions describing the positive prefix String. This is
4079      * lazily created. Use <code>getPositivePrefixFieldPositions</code>
4080      * when needed.
4081      */
4082     private transient FieldPosition[] positivePrefixFieldPositions;
4083 
4084     /**
4085      * FieldPositions describing the positive suffix String. This is
4086      * lazily created. Use <code>getPositiveSuffixFieldPositions</code>
4087      * when needed.
4088      */
4089     private transient FieldPosition[] positiveSuffixFieldPositions;
4090 
4091     /**
4092      * FieldPositions describing the negative prefix String. This is
4093      * lazily created. Use <code>getNegativePrefixFieldPositions</code>
4094      * when needed.
4095      */
4096     private transient FieldPosition[] negativePrefixFieldPositions;
4097 
4098     /**
4099      * FieldPositions describing the negative suffix String. This is
4100      * lazily created. Use <code>getNegativeSuffixFieldPositions</code>
4101      * when needed.
4102      */
4103     private transient FieldPosition[] negativeSuffixFieldPositions;
4104 
4105     /**
4106      * The minimum number of digits used to display the exponent when a number is
4107      * formatted in exponential notation.  This field is ignored if
4108      * <code>useExponentialNotation</code> is not true.
4109      *
4110      * @serial
4111      * @since 1.2
4112      */
4113     private byte    minExponentDigits;       // Newly persistent in the Java 2 platform v.1.2
4114 
4115     /**
4116      * The maximum number of digits allowed in the integer portion of a
4117      * <code>BigInteger</code> or <code>BigDecimal</code> number.
4118      * <code>maximumIntegerDigits</code> must be greater than or equal to
4119      * <code>minimumIntegerDigits</code>.
4120      *
4121      * @serial
4122      * @see #getMaximumIntegerDigits
4123      * @since 1.5
4124      */
4125     private int    maximumIntegerDigits = super.getMaximumIntegerDigits();
4126 
4127     /**
4128      * The minimum number of digits allowed in the integer portion of a
4129      * <code>BigInteger</code> or <code>BigDecimal</code> number.
4130      * <code>minimumIntegerDigits</code> must be less than or equal to
4131      * <code>maximumIntegerDigits</code>.
4132      *
4133      * @serial
4134      * @see #getMinimumIntegerDigits
4135      * @since 1.5
4136      */
4137     private int    minimumIntegerDigits = super.getMinimumIntegerDigits();
4138 
4139     /**
4140      * The maximum number of digits allowed in the fractional portion of a
4141      * <code>BigInteger</code> or <code>BigDecimal</code> number.
4142      * <code>maximumFractionDigits</code> must be greater than or equal to
4143      * <code>minimumFractionDigits</code>.
4144      *
4145      * @serial
4146      * @see #getMaximumFractionDigits
4147      * @since 1.5
4148      */
4149     private int    maximumFractionDigits = super.getMaximumFractionDigits();
4150 
4151     /**
4152      * The minimum number of digits allowed in the fractional portion of a
4153      * <code>BigInteger</code> or <code>BigDecimal</code> number.
4154      * <code>minimumFractionDigits</code> must be less than or equal to
4155      * <code>maximumFractionDigits</code>.
4156      *
4157      * @serial
4158      * @see #getMinimumFractionDigits
4159      * @since 1.5
4160      */
4161     private int    minimumFractionDigits = super.getMinimumFractionDigits();
4162 
4163     /**
4164      * The {@link java.math.RoundingMode} used in this DecimalFormat.
4165      *
4166      * @serial
4167      * @since 1.6
4168      */
4169     private RoundingMode roundingMode = RoundingMode.HALF_EVEN;
4170 
4171     // ------ DecimalFormat fields for fast-path for double algorithm  ------
4172 
4173     /**
4174      * Helper inner utility class for storing the data used in the fast-path
4175      * algorithm. Almost all fields related to fast-path are encapsulated in
4176      * this class.
4177      *
4178      * Any {@code DecimalFormat} instance has a {@code fastPathData}
4179      * reference field that is null unless both the properties of the instance
4180      * are such that the instance is in the "fast-path" state, and a format call
4181      * has been done at least once while in this state.
4182      *
4183      * Almost all fields are related to the "fast-path" state only and don't
4184      * change until one of the instance properties is changed.
4185      *
4186      * {@code firstUsedIndex} and {@code lastFreeIndex} are the only
4187      * two fields that are used and modified while inside a call to
4188      * {@code fastDoubleFormat}.
4189      *
4190      */
4191     private static class FastPathData {
4192         // --- Temporary fields used in fast-path, shared by several methods.
4193 
4194         /** The first unused index at the end of the formatted result. */
4195         int lastFreeIndex;
4196 
4197         /** The first used index at the beginning of the formatted result */
4198         int firstUsedIndex;
4199 
4200         // --- State fields related to fast-path status. Changes due to a
4201         //     property change only. Set by checkAndSetFastPathStatus() only.
4202 
4203         /** Difference between locale zero and default zero representation. */
4204         int  zeroDelta;
4205 
4206         /** Locale char for grouping separator. */
4207         char groupingChar;
4208 
4209         /**  Fixed index position of last integral digit of formatted result */
4210         int integralLastIndex;
4211 
4212         /**  Fixed index position of first fractional digit of formatted result */
4213         int fractionalFirstIndex;
4214 
4215         /** Fractional constants depending on decimal|currency state */
4216         double fractionalScaleFactor;
4217         int fractionalMaxIntBound;
4218 
4219 
4220         /** The char array buffer that will contain the formatted result */
4221         char[] fastPathContainer;
4222 
4223         /** Suffixes recorded as char array for efficiency. */
4224         char[] charsPositivePrefix;
4225         char[] charsNegativePrefix;
4226         char[] charsPositiveSuffix;
4227         char[] charsNegativeSuffix;
4228         boolean positiveAffixesRequired = true;
4229         boolean negativeAffixesRequired = true;
4230     }
4231 
4232     /** The format fast-path status of the instance. Logical state. */
4233     private transient boolean isFastPath = false;
4234 
4235     /** Flag stating need of check and reinit fast-path status on next format call. */
4236     private transient boolean fastPathCheckNeeded = true;
4237 
4238     /** DecimalFormat reference to its FastPathData */
4239     private transient FastPathData fastPathData;
4240 
4241 
4242     //----------------------------------------------------------------------
4243 
4244     static final int currentSerialVersion = 4;
4245 
4246     /**
4247      * The internal serial version which says which version was written.
4248      * Possible values are:
4249      * <ul>
4250      * <li><b>0</b> (default): versions before the Java 2 platform v1.2
4251      * <li><b>1</b>: version for 1.2, which includes the two new fields
4252      *      <code>useExponentialNotation</code> and
4253      *      <code>minExponentDigits</code>.
4254      * <li><b>2</b>: version for 1.3 and later, which adds four new fields:
4255      *      <code>posPrefixPattern</code>, <code>posSuffixPattern</code>,
4256      *      <code>negPrefixPattern</code>, and <code>negSuffixPattern</code>.
4257      * <li><b>3</b>: version for 1.5 and later, which adds five new fields:
4258      *      <code>maximumIntegerDigits</code>,
4259      *      <code>minimumIntegerDigits</code>,
4260      *      <code>maximumFractionDigits</code>,
4261      *      <code>minimumFractionDigits</code>, and
4262      *      <code>parseBigDecimal</code>.
4263      * <li><b>4</b>: version for 1.6 and later, which adds one new field:
4264      *      <code>roundingMode</code>.
4265      * </ul>
4266      * @since 1.2
4267      * @serial
4268      */
4269     private int serialVersionOnStream = currentSerialVersion;
4270 
4271     //----------------------------------------------------------------------
4272     // CONSTANTS
4273     //----------------------------------------------------------------------
4274 
4275     // ------ Fast-Path for double Constants ------
4276 
4277     /** Maximum valid integer value for applying fast-path algorithm */
4278     private static final double MAX_INT_AS_DOUBLE = (double) Integer.MAX_VALUE;
4279 
4280     /**
4281      * The digit arrays used in the fast-path methods for collecting digits.
4282      * Using 3 constants arrays of chars ensures a very fast collection of digits
4283      */
4284     private static class DigitArrays {
4285         static final char[] DigitOnes1000 = new char[1000];
4286         static final char[] DigitTens1000 = new char[1000];
4287         static final char[] DigitHundreds1000 = new char[1000];
4288 
4289         // initialize on demand holder class idiom for arrays of digits
4290         static {
4291             int tenIndex = 0;
4292             int hundredIndex = 0;
4293             char digitOne = '0';
4294             char digitTen = '0';
4295             char digitHundred = '0';
4296             for (int i = 0;  i < 1000; i++ ) {
4297 
4298                 DigitOnes1000[i] = digitOne;
4299                 if (digitOne == '9')
4300                     digitOne = '0';
4301                 else
4302                     digitOne++;
4303 
4304                 DigitTens1000[i] = digitTen;
4305                 if (i == (tenIndex + 9)) {
4306                     tenIndex += 10;
4307                     if (digitTen == '9')
4308                         digitTen = '0';
4309                     else
4310                         digitTen++;
4311                 }
4312 
4313                 DigitHundreds1000[i] = digitHundred;
4314                 if (i == (hundredIndex + 99)) {
4315                     digitHundred++;
4316                     hundredIndex += 100;
4317                 }
4318             }
4319         }
4320     }
4321     // ------ Fast-Path for double Constants end ------
4322 
4323     // Constants for characters used in programmatic (unlocalized) patterns.
4324     private static final char       PATTERN_ZERO_DIGIT         = '0';
4325     private static final char       PATTERN_GROUPING_SEPARATOR = ',';
4326     private static final char       PATTERN_DECIMAL_SEPARATOR  = '.';
4327     private static final char       PATTERN_PER_MILLE          = '\u2030';
4328     private static final char       PATTERN_PERCENT            = '%';
4329     private static final char       PATTERN_DIGIT              = '#';
4330     private static final char       PATTERN_SEPARATOR          = ';';
4331     private static final String     PATTERN_EXPONENT           = "E";
4332     private static final char       PATTERN_MINUS              = '-';
4333 
4334     /**
4335      * The CURRENCY_SIGN is the standard Unicode symbol for currency.  It
4336      * is used in patterns and substituted with either the currency symbol,
4337      * or if it is doubled, with the international currency symbol.  If the
4338      * CURRENCY_SIGN is seen in a pattern, then the decimal separator is
4339      * replaced with the monetary decimal separator.
4340      *
4341      * The CURRENCY_SIGN is not localized.
4342      */
4343     private static final char       CURRENCY_SIGN = '\u00A4';
4344 
4345     private static final char       QUOTE = '\'';
4346 
4347     private static FieldPosition[] EmptyFieldPositionArray = new FieldPosition[0];
4348 
4349     // Upper limit on integer and fraction digits for a Java double
4350     static final int DOUBLE_INTEGER_DIGITS  = 309;
4351     static final int DOUBLE_FRACTION_DIGITS = 340;
4352 
4353     // Upper limit on integer and fraction digits for BigDecimal and BigInteger
4354     static final int MAXIMUM_INTEGER_DIGITS  = Integer.MAX_VALUE;
4355     static final int MAXIMUM_FRACTION_DIGITS = Integer.MAX_VALUE;
4356 
4357     // Proclaim JDK 1.1 serial compatibility.
4358     static final long serialVersionUID = 864413376551465018L;
4359 }