1 /*
2 * Copyright (c) 1994, 2013, 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 package java.lang;
27
28 import java.lang.annotation.Native;
29 import java.math.*;
30 import java.util.Objects;
31
32
33 /**
34 * The {@code Long} class wraps a value of the primitive type {@code
35 * long} in an object. An object of type {@code Long} contains a
36 * single field whose type is {@code long}.
37 *
38 * <p> In addition, this class provides several methods for converting
39 * a {@code long} to a {@code String} and a {@code String} to a {@code
40 * long}, as well as other constants and methods useful when dealing
41 * with a {@code long}.
42 *
43 * <p>Implementation note: The implementations of the "bit twiddling"
44 * methods (such as {@link #highestOneBit(long) highestOneBit} and
45 * {@link #numberOfTrailingZeros(long) numberOfTrailingZeros}) are
46 * based on material from Henry S. Warren, Jr.'s <i>Hacker's
47 * Delight</i>, (Addison Wesley, 2002).
48 *
49 * @author Lee Boynton
50 * @author Arthur van Hoff
51 * @author Josh Bloch
52 * @author Joseph D. Darcy
53 * @since JDK1.0
54 */
55 public final class Long extends Number implements Comparable<Long> {
56 /**
57 * A constant holding the minimum value a {@code long} can
58 * have, -2<sup>63</sup>.
59 */
60 @Native public static final long MIN_VALUE = 0x8000000000000000L;
61
62 /**
63 * A constant holding the maximum value a {@code long} can
64 * have, 2<sup>63</sup>-1.
65 */
66 @Native public static final long MAX_VALUE = 0x7fffffffffffffffL;
67
68 /**
69 * The {@code Class} instance representing the primitive type
70 * {@code long}.
71 *
72 * @since JDK1.1
73 */
74 @SuppressWarnings("unchecked")
75 public static final Class<Long> TYPE = (Class<Long>) Class.getPrimitiveClass("long");
76
77 /**
78 * Returns a string representation of the first argument in the
79 * radix specified by the second argument.
80 *
81 * <p>If the radix is smaller than {@code Character.MIN_RADIX}
82 * or larger than {@code Character.MAX_RADIX}, then the radix
83 * {@code 10} is used instead.
84 *
85 * <p>If the first argument is negative, the first element of the
86 * result is the ASCII minus sign {@code '-'}
87 * ({@code '\u005Cu002d'}). If the first argument is not
88 * negative, no sign character appears in the result.
89 *
90 * <p>The remaining characters of the result represent the magnitude
91 * of the first argument. If the magnitude is zero, it is
92 * represented by a single zero character {@code '0'}
93 * ({@code '\u005Cu0030'}); otherwise, the first character of
94 * the representation of the magnitude will not be the zero
95 * character. The following ASCII characters are used as digits:
96 *
97 * <blockquote>
98 * {@code 0123456789abcdefghijklmnopqrstuvwxyz}
99 * </blockquote>
100 *
101 * These are {@code '\u005Cu0030'} through
102 * {@code '\u005Cu0039'} and {@code '\u005Cu0061'} through
103 * {@code '\u005Cu007a'}. If {@code radix} is
104 * <var>N</var>, then the first <var>N</var> of these characters
105 * are used as radix-<var>N</var> digits in the order shown. Thus,
106 * the digits for hexadecimal (radix 16) are
107 * {@code 0123456789abcdef}. If uppercase letters are
108 * desired, the {@link java.lang.String#toUpperCase()} method may
109 * be called on the result:
110 *
111 * <blockquote>
112 * {@code Long.toString(n, 16).toUpperCase()}
113 * </blockquote>
114 *
115 * @param i a {@code long} to be converted to a string.
116 * @param radix the radix to use in the string representation.
117 * @return a string representation of the argument in the specified radix.
118 * @see java.lang.Character#MAX_RADIX
119 * @see java.lang.Character#MIN_RADIX
120 */
121 public static String toString(long i, int radix) {
122 if (radix < Character.MIN_RADIX || radix > Character.MAX_RADIX)
123 radix = 10;
124 if (radix == 10)
125 return toString(i);
126 char[] buf = new char[65];
127 int charPos = 64;
128 boolean negative = (i < 0);
129
130 if (!negative) {
131 i = -i;
132 }
133
134 while (i <= -radix) {
135 buf[charPos--] = Integer.digits[(int)(-(i % radix))];
136 i = i / radix;
137 }
138 buf[charPos] = Integer.digits[(int)(-i)];
139
140 if (negative) {
141 buf[--charPos] = '-';
142 }
143
144 return new String(buf, charPos, (65 - charPos));
145 }
146
147 /**
148 * Returns a string representation of the first argument as an
149 * unsigned integer value in the radix specified by the second
150 * argument.
151 *
152 * <p>If the radix is smaller than {@code Character.MIN_RADIX}
153 * or larger than {@code Character.MAX_RADIX}, then the radix
154 * {@code 10} is used instead.
155 *
156 * <p>Note that since the first argument is treated as an unsigned
157 * value, no leading sign character is printed.
158 *
159 * <p>If the magnitude is zero, it is represented by a single zero
160 * character {@code '0'} ({@code '\u005Cu0030'}); otherwise,
161 * the first character of the representation of the magnitude will
162 * not be the zero character.
163 *
164 * <p>The behavior of radixes and the characters used as digits
165 * are the same as {@link #toString(long, int) toString}.
166 *
167 * @param i an integer to be converted to an unsigned string.
168 * @param radix the radix to use in the string representation.
169 * @return an unsigned string representation of the argument in the specified radix.
170 * @see #toString(long, int)
171 * @since 1.8
172 */
173 public static String toUnsignedString(long i, int radix) {
174 if (i >= 0)
175 return toString(i, radix);
176 else {
177 switch (radix) {
178 case 2:
179 return toBinaryString(i);
180
181 case 4:
182 return toUnsignedString0(i, 2);
183
184 case 8:
185 return toOctalString(i);
186
187 case 10:
188 /*
189 * We can get the effect of an unsigned division by 10
190 * on a long value by first shifting right, yielding a
191 * positive value, and then dividing by 5. This
192 * allows the last digit and preceding digits to be
193 * isolated more quickly than by an initial conversion
194 * to BigInteger.
195 */
196 long quot = (i >>> 1) / 5;
197 long rem = i - quot * 10;
198 return toString(quot) + rem;
199
200 case 16:
201 return toHexString(i);
202
203 case 32:
204 return toUnsignedString0(i, 5);
205
206 default:
207 return toUnsignedBigInteger(i).toString(radix);
208 }
209 }
210 }
211
212 /**
213 * Return a BigInteger equal to the unsigned value of the
214 * argument.
215 */
216 private static BigInteger toUnsignedBigInteger(long i) {
217 if (i >= 0L)
218 return BigInteger.valueOf(i);
219 else {
220 int upper = (int) (i >>> 32);
221 int lower = (int) i;
222
223 // return (upper << 32) + lower
224 return (BigInteger.valueOf(Integer.toUnsignedLong(upper))).shiftLeft(32).
225 add(BigInteger.valueOf(Integer.toUnsignedLong(lower)));
226 }
227 }
228
229 /**
230 * Returns a string representation of the {@code long}
231 * argument as an unsigned integer in base 16.
232 *
233 * <p>The unsigned {@code long} value is the argument plus
234 * 2<sup>64</sup> if the argument is negative; otherwise, it is
235 * equal to the argument. This value is converted to a string of
236 * ASCII digits in hexadecimal (base 16) with no extra
237 * leading {@code 0}s.
238 *
239 * <p>The value of the argument can be recovered from the returned
240 * string {@code s} by calling {@link
241 * Long#parseUnsignedLong(String, int) Long.parseUnsignedLong(s,
242 * 16)}.
243 *
244 * <p>If the unsigned magnitude is zero, it is represented by a
245 * single zero character {@code '0'} ({@code '\u005Cu0030'});
246 * otherwise, the first character of the representation of the
247 * unsigned magnitude will not be the zero character. The
248 * following characters are used as hexadecimal digits:
249 *
250 * <blockquote>
251 * {@code 0123456789abcdef}
252 * </blockquote>
253 *
254 * These are the characters {@code '\u005Cu0030'} through
255 * {@code '\u005Cu0039'} and {@code '\u005Cu0061'} through
256 * {@code '\u005Cu0066'}. If uppercase letters are desired,
257 * the {@link java.lang.String#toUpperCase()} method may be called
258 * on the result:
259 *
260 * <blockquote>
261 * {@code Long.toHexString(n).toUpperCase()}
262 * </blockquote>
263 *
264 * @param i a {@code long} to be converted to a string.
265 * @return the string representation of the unsigned {@code long}
266 * value represented by the argument in hexadecimal
267 * (base 16).
268 * @see #parseUnsignedLong(String, int)
269 * @see #toUnsignedString(long, int)
270 * @since JDK 1.0.2
271 */
272 public static String toHexString(long i) {
273 return toUnsignedString0(i, 4);
274 }
275
276 /**
277 * Returns a string representation of the {@code long}
278 * argument as an unsigned integer in base 8.
279 *
280 * <p>The unsigned {@code long} value is the argument plus
281 * 2<sup>64</sup> if the argument is negative; otherwise, it is
282 * equal to the argument. This value is converted to a string of
283 * ASCII digits in octal (base 8) with no extra leading
284 * {@code 0}s.
285 *
286 * <p>The value of the argument can be recovered from the returned
287 * string {@code s} by calling {@link
288 * Long#parseUnsignedLong(String, int) Long.parseUnsignedLong(s,
289 * 8)}.
290 *
291 * <p>If the unsigned magnitude is zero, it is represented by a
292 * single zero character {@code '0'} ({@code '\u005Cu0030'});
293 * otherwise, the first character of the representation of the
294 * unsigned magnitude will not be the zero character. The
295 * following characters are used as octal digits:
296 *
297 * <blockquote>
298 * {@code 01234567}
299 * </blockquote>
300 *
301 * These are the characters {@code '\u005Cu0030'} through
302 * {@code '\u005Cu0037'}.
303 *
304 * @param i a {@code long} to be converted to a string.
305 * @return the string representation of the unsigned {@code long}
306 * value represented by the argument in octal (base 8).
307 * @see #parseUnsignedLong(String, int)
308 * @see #toUnsignedString(long, int)
309 * @since JDK 1.0.2
310 */
311 public static String toOctalString(long i) {
312 return toUnsignedString0(i, 3);
313 }
314
315 /**
316 * Returns a string representation of the {@code long}
317 * argument as an unsigned integer in base 2.
318 *
319 * <p>The unsigned {@code long} value is the argument plus
320 * 2<sup>64</sup> if the argument is negative; otherwise, it is
321 * equal to the argument. This value is converted to a string of
322 * ASCII digits in binary (base 2) with no extra leading
323 * {@code 0}s.
324 *
325 * <p>The value of the argument can be recovered from the returned
326 * string {@code s} by calling {@link
327 * Long#parseUnsignedLong(String, int) Long.parseUnsignedLong(s,
328 * 2)}.
329 *
330 * <p>If the unsigned magnitude is zero, it is represented by a
331 * single zero character {@code '0'} ({@code '\u005Cu0030'});
332 * otherwise, the first character of the representation of the
333 * unsigned magnitude will not be the zero character. The
334 * characters {@code '0'} ({@code '\u005Cu0030'}) and {@code
335 * '1'} ({@code '\u005Cu0031'}) are used as binary digits.
336 *
337 * @param i a {@code long} to be converted to a string.
338 * @return the string representation of the unsigned {@code long}
339 * value represented by the argument in binary (base 2).
340 * @see #parseUnsignedLong(String, int)
341 * @see #toUnsignedString(long, int)
342 * @since JDK 1.0.2
343 */
344 public static String toBinaryString(long i) {
345 return toUnsignedString0(i, 1);
346 }
347
348 /**
349 * Format a long (treated as unsigned) into a String.
350 * @param val the value to format
351 * @param shift the log2 of the base to format in (4 for hex, 3 for octal, 1 for binary)
352 */
353 static String toUnsignedString0(long val, int shift) {
354 // assert shift > 0 && shift <=5 : "Illegal shift value";
355 int mag = Long.SIZE - Long.numberOfLeadingZeros(val);
356 int chars = Math.max(((mag + (shift - 1)) / shift), 1);
357 char[] buf = new char[chars];
358
359 formatUnsignedLong(val, shift, buf, 0, chars);
360 return new String(buf, true);
361 }
362
363 /**
364 * Format a long (treated as unsigned) into a character buffer. If
365 * {@code len} exceeds the formatted ASCII representation of {@code val},
366 * {@code buf} will be padded with leading zeroes.
367 *
368 * @param val the unsigned long to format
369 * @param shift the log2 of the base to format in (4 for hex, 3 for octal, 1 for binary)
370 * @param buf the character buffer to write to
371 * @param offset the offset in the destination buffer to start at
372 * @param len the number of characters to write
373 */
374 static void formatUnsignedLong(long val, int shift, char[] buf, int offset, int len) {
375 // assert shift > 0 && shift <=5 : "Illegal shift value";
376 // assert offset >= 0 && offset < buf.length : "illegal offset";
377 // assert len > 0 && (offset + len) <= buf.length : "illegal length";
378 int charPos = offset + len;
379 int radix = 1 << shift;
380 int mask = radix - 1;
381 do {
382 buf[--charPos] = Integer.digits[((int) val) & mask];
383 val >>>= shift;
384 } while (charPos > offset);
385 }
386
387 /**
388 * Returns a {@code String} object representing the specified
389 * {@code long}. The argument is converted to signed decimal
390 * representation and returned as a string, exactly as if the
391 * argument and the radix 10 were given as arguments to the {@link
392 * #toString(long, int)} method.
393 *
394 * @param i a {@code long} to be converted.
395 * @return a string representation of the argument in base 10.
396 */
397 public static String toString(long i) {
398 if (i == Long.MIN_VALUE)
399 return "-9223372036854775808";
400 int size = (i < 0) ? stringSize(-i) + 1 : stringSize(i);
401 char[] buf = new char[size];
402 getChars(i, size, buf);
403 return new String(buf, true);
404 }
405
406 /**
407 * Returns a string representation of the argument as an unsigned
408 * decimal value.
409 *
410 * The argument is converted to unsigned decimal representation
411 * and returned as a string exactly as if the argument and radix
412 * 10 were given as arguments to the {@link #toUnsignedString(long,
413 * int)} method.
414 *
415 * @param i an integer to be converted to an unsigned string.
416 * @return an unsigned string representation of the argument.
417 * @see #toUnsignedString(long, int)
418 * @since 1.8
419 */
420 public static String toUnsignedString(long i) {
421 return toUnsignedString(i, 10);
422 }
423
424 /**
425 * Places characters representing the integer i into the
426 * character array buf. The characters are placed into
427 * the buffer backwards starting with the least significant
428 * digit at the specified index (exclusive), and working
429 * backwards from there.
430 *
431 * Will fail if i == Long.MIN_VALUE
432 */
433 static void getChars(long i, int index, char[] buf) {
434 long q;
435 int r;
436 int charPos = index;
437 char sign = 0;
438
439 if (i < 0) {
440 sign = '-';
441 i = -i;
442 }
443
444 // Get 2 digits/iteration using longs until quotient fits into an int
445 while (i > Integer.MAX_VALUE) {
446 q = i / 100;
447 // really: r = i - (q * 100);
448 r = (int)(i - ((q << 6) + (q << 5) + (q << 2)));
449 i = q;
450 buf[--charPos] = Integer.DigitOnes[r];
451 buf[--charPos] = Integer.DigitTens[r];
452 }
453
454 // Get 2 digits/iteration using ints
455 int q2;
456 int i2 = (int)i;
457 while (i2 >= 65536) {
458 q2 = i2 / 100;
459 // really: r = i2 - (q * 100);
460 r = i2 - ((q2 << 6) + (q2 << 5) + (q2 << 2));
461 i2 = q2;
462 buf[--charPos] = Integer.DigitOnes[r];
463 buf[--charPos] = Integer.DigitTens[r];
464 }
465
466 // Fall thru to fast mode for smaller numbers
467 // assert(i2 <= 65536, i2);
468 for (;;) {
469 q2 = (i2 * 52429) >>> (16+3);
470 r = i2 - ((q2 << 3) + (q2 << 1)); // r = i2-(q2*10) ...
471 buf[--charPos] = Integer.digits[r];
472 i2 = q2;
473 if (i2 == 0) break;
474 }
475 if (sign != 0) {
476 buf[--charPos] = sign;
477 }
478 }
479
480 // Requires positive x
481 static int stringSize(long x) {
482 long p = 10;
483 for (int i=1; i<19; i++) {
484 if (x < p)
485 return i;
486 p = 10*p;
487 }
488 return 19;
489 }
490
491 /**
492 * Parses the string argument as a signed {@code long} in the
493 * radix specified by the second argument. The characters in the
494 * string must all be digits of the specified radix (as determined
495 * by whether {@link java.lang.Character#digit(char, int)} returns
496 * a nonnegative value), except that the first character may be an
497 * ASCII minus sign {@code '-'} ({@code '\u005Cu002D'}) to
498 * indicate a negative value or an ASCII plus sign {@code '+'}
499 * ({@code '\u005Cu002B'}) to indicate a positive value. The
500 * resulting {@code long} value is returned.
501 *
502 * <p>Note that neither the character {@code L}
503 * ({@code '\u005Cu004C'}) nor {@code l}
504 * ({@code '\u005Cu006C'}) is permitted to appear at the end
505 * of the string as a type indicator, as would be permitted in
506 * Java programming language source code - except that either
507 * {@code L} or {@code l} may appear as a digit for a
508 * radix greater than or equal to 22.
509 *
510 * <p>An exception of type {@code NumberFormatException} is
511 * thrown if any of the following situations occurs:
512 * <ul>
513 *
514 * <li>The first argument is {@code null} or is a string of
515 * length zero.
516 *
517 * <li>The {@code radix} is either smaller than {@link
518 * java.lang.Character#MIN_RADIX} or larger than {@link
519 * java.lang.Character#MAX_RADIX}.
520 *
521 * <li>Any character of the string is not a digit of the specified
522 * radix, except that the first character may be a minus sign
523 * {@code '-'} ({@code '\u005Cu002d'}) or plus sign {@code
524 * '+'} ({@code '\u005Cu002B'}) provided that the string is
525 * longer than length 1.
526 *
527 * <li>The value represented by the string is not a value of type
528 * {@code long}.
529 * </ul>
530 *
531 * <p>Examples:
532 * <blockquote><pre>
533 * parseLong("0", 10) returns 0L
534 * parseLong("473", 10) returns 473L
535 * parseLong("+42", 10) returns 42L
536 * parseLong("-0", 10) returns 0L
537 * parseLong("-FF", 16) returns -255L
538 * parseLong("1100110", 2) returns 102L
539 * parseLong("99", 8) throws a NumberFormatException
540 * parseLong("Hazelnut", 10) throws a NumberFormatException
541 * parseLong("Hazelnut", 36) returns 1356099454469L
542 * </pre></blockquote>
543 *
544 * @param s the {@code String} containing the
545 * {@code long} representation to be parsed.
546 * @param radix the radix to be used while parsing {@code s}.
547 * @return the {@code long} represented by the string argument in
548 * the specified radix.
549 * @throws NumberFormatException if the string does not contain a
550 * parsable {@code long}.
551 */
552 public static long parseLong(String s, int radix)
553 throws NumberFormatException
554 {
555 if (s == null) {
556 throw new NumberFormatException("null");
557 }
558
559 if (radix < Character.MIN_RADIX) {
560 throw new NumberFormatException("radix " + radix +
561 " less than Character.MIN_RADIX");
562 }
563 if (radix > Character.MAX_RADIX) {
564 throw new NumberFormatException("radix " + radix +
565 " greater than Character.MAX_RADIX");
566 }
567
568 boolean negative = false;
569 int i = 0, len = s.length();
570 long limit = -Long.MAX_VALUE;
571
572 if (len > 0) {
573 char firstChar = s.charAt(0);
574 if (firstChar < '0') { // Possible leading "+" or "-"
575 if (firstChar == '-') {
576 negative = true;
577 limit = Long.MIN_VALUE;
578 } else if (firstChar != '+') {
579 throw NumberFormatException.forInputString(s);
580 }
581
582 if (len == 1) { // Cannot have lone "+" or "-"
583 throw NumberFormatException.forInputString(s);
584 }
585 i++;
586 }
587 long multmin = limit / radix;
588 long result = 0;
589 while (i < len) {
590 // Accumulating negatively avoids surprises near MAX_VALUE
591 int digit = Character.digit(s.charAt(i++),radix);
592 if (digit < 0 || result < multmin) {
593 throw NumberFormatException.forInputString(s);
594 }
595 result *= radix;
596 if (result < limit + digit) {
597 throw NumberFormatException.forInputString(s);
598 }
599 result -= digit;
600 }
601 return negative ? result : -result;
602 } else {
603 throw NumberFormatException.forInputString(s);
604 }
605 }
606
607 /**
608 * Parses the {@link CharSequence} argument as a signed {@code long} in
609 * the specified {@code radix}, beginning at the specified {@code beginIndex}
610 * and extending to the end of the sequence.
611 *
612 * <p>The method does not take steps to guard against the
613 * {@code CharSequence} being mutated while parsing.
614 *
615 * @param s the {@code CharSequence} containing the {@code long}
616 * representation to be parsed
617 * @param radix the radix to be used while parsing {@code s}.
618 * @param beginIndex the beginning index, inclusive.
619 * @return the signed {@code long} represented by the subsequence in
620 * the specified radix.
621 * @throws NullPointerException if {@code s} is null.
622 * @throws IndexOutOfBoundsException if {@code beginIndex} is
623 * negative, or if {@code beginIndex} is greater than
624 * {@code s.length()}.
625 * @throws NumberFormatException if the {@code CharSequence} does not
626 * contain a parsable {@code long} in the specified
627 * {@code radix}, or if {@code radix} is either smaller than
628 * {@link java.lang.Character#MIN_RADIX} or larger than
629 * {@link java.lang.Character#MAX_RADIX}.
630 * @since 1.9
631 */
632 static long parseLong(CharSequence s, int radix, int beginIndex)
633 throws NumberFormatException {
634 // forces a null check of s
635 return parseLong(s, radix, beginIndex, s.length());
636 }
637
638 /**
639 * Parses the {@link CharSequence} argument as a signed {@code long} in
640 * the specified {@code radix}, beginning at the specified
641 * {@code beginIndex} and extending to {@code endIndex - 1}.
642 *
643 * <p>The method does not take steps to guard against the
644 * {@code CharSequence} being mutated while parsing.
645 *
646 * @param s the {@code CharSequence} containing the {@code long}
647 * representation to be parsed
648 * @param radix the radix to be used while parsing {@code s}.
649 * @param beginIndex the beginning index, inclusive.
650 * @param endIndex the ending index, exclusive.
651 * @return the signed {@code long} represented by the subsequence in
652 * the specified radix.
653 * @throws NullPointerException if {@code s} is null.
654 * @throws IndexOutOfBoundsException if {@code beginIndex} is
655 * negative, or if {@code beginIndex} is greater than
656 * {@code endIndex} or if {@code endIndex} is greater than
657 * {@code s.length()}.
658 * @throws NumberFormatException if the {@code CharSequence} does not
659 * contain a parsable {@code int} in the specified
660 * {@code radix}, or if {@code radix} is either smaller than
661 * {@link java.lang.Character#MIN_RADIX} or larger than
662 * {@link java.lang.Character#MAX_RADIX}.
663 * @since 1.9
664 */
665 static long parseLong(CharSequence s, int radix, int beginIndex, int endIndex)
666 throws NumberFormatException {
667 s = Objects.requireNonNull(s);
668
669 if (beginIndex < 0 || beginIndex > endIndex || endIndex > s.length()) {
670 throw new IndexOutOfBoundsException();
671 }
672 if (radix < Character.MIN_RADIX) {
673 throw new NumberFormatException("radix " + radix +
674 " less than Character.MIN_RADIX");
675 }
676 if (radix > Character.MAX_RADIX) {
677 throw new NumberFormatException("radix " + radix +
678 " greater than Character.MAX_RADIX");
679 }
680
681 boolean negative = false;
682 int i = beginIndex;
683 long limit = -Long.MAX_VALUE;
684
685 if (i < endIndex) {
686 char firstChar = s.charAt(i);
687 if (firstChar < '0') { // Possible leading "+" or "-"
688 if (firstChar == '-') {
689 negative = true;
690 limit = Long.MIN_VALUE;
691 } else if (firstChar != '+') {
692 throw NumberFormatException.forCharSequence(s, beginIndex,
693 endIndex, i);
694 }
695 i++;
696 }
697 if (i >= endIndex) { // Cannot have lone "+", "-" or ""
698 throw NumberFormatException.forCharSequence(s, beginIndex,
699 endIndex, i);
700 }
701 long multmin = limit / radix;
702 long result = 0;
703 while (i < endIndex) {
704 // Accumulating negatively avoids surprises near MAX_VALUE
705 int digit = Character.digit(s.charAt(i++), radix);
706 if (digit < 0 || result < multmin) {
707 throw NumberFormatException.forCharSequence(s, beginIndex,
708 endIndex, i);
709 }
710 result *= radix;
711 if (result < limit + digit) {
712 throw NumberFormatException.forCharSequence(s, beginIndex,
713 endIndex, i);
714 }
715 result -= digit;
716 }
717 return negative ? result : -result;
718 } else {
719 throw new NumberFormatException("");
720 }
721 }
722
723 /**
724 * Parses the string argument as a signed decimal {@code long}.
725 * The characters in the string must all be decimal digits, except
726 * that the first character may be an ASCII minus sign {@code '-'}
727 * ({@code \u005Cu002D'}) to indicate a negative value or an
728 * ASCII plus sign {@code '+'} ({@code '\u005Cu002B'}) to
729 * indicate a positive value. The resulting {@code long} value is
730 * returned, exactly as if the argument and the radix {@code 10}
731 * were given as arguments to the {@link
732 * #parseLong(java.lang.String, int)} method.
733 *
734 * <p>Note that neither the character {@code L}
735 * ({@code '\u005Cu004C'}) nor {@code l}
736 * ({@code '\u005Cu006C'}) is permitted to appear at the end
737 * of the string as a type indicator, as would be permitted in
738 * Java programming language source code.
739 *
740 * @param s a {@code String} containing the {@code long}
741 * representation to be parsed
742 * @return the {@code long} represented by the argument in
743 * decimal.
744 * @throws NumberFormatException if the string does not contain a
745 * parsable {@code long}.
746 */
747 public static long parseLong(String s) throws NumberFormatException {
748 return parseLong(s, 10);
749 }
750
751 /**
752 * Parses the string argument as an unsigned {@code long} in the
753 * radix specified by the second argument. An unsigned integer
754 * maps the values usually associated with negative numbers to
755 * positive numbers larger than {@code MAX_VALUE}.
756 *
757 * The characters in the string must all be digits of the
758 * specified radix (as determined by whether {@link
759 * java.lang.Character#digit(char, int)} returns a nonnegative
760 * value), except that the first character may be an ASCII plus
761 * sign {@code '+'} ({@code '\u005Cu002B'}). The resulting
762 * integer value is returned.
763 *
764 * <p>An exception of type {@code NumberFormatException} is
765 * thrown if any of the following situations occurs:
766 * <ul>
767 * <li>The first argument is {@code null} or is a string of
768 * length zero.
769 *
770 * <li>The radix is either smaller than
771 * {@link java.lang.Character#MIN_RADIX} or
772 * larger than {@link java.lang.Character#MAX_RADIX}.
773 *
774 * <li>Any character of the string is not a digit of the specified
775 * radix, except that the first character may be a plus sign
776 * {@code '+'} ({@code '\u005Cu002B'}) provided that the
777 * string is longer than length 1.
778 *
779 * <li>The value represented by the string is larger than the
780 * largest unsigned {@code long}, 2<sup>64</sup>-1.
781 *
782 * </ul>
783 *
784 *
785 * @param s the {@code String} containing the unsigned integer
786 * representation to be parsed
787 * @param radix the radix to be used while parsing {@code s}.
788 * @return the unsigned {@code long} represented by the string
789 * argument in the specified radix.
790 * @throws NumberFormatException if the {@code String}
791 * does not contain a parsable {@code long}.
792 * @since 1.8
793 */
794 public static long parseUnsignedLong(String s, int radix)
795 throws NumberFormatException {
796 if (s == null) {
797 throw new NumberFormatException("null");
798 }
799
800 int len = s.length();
801 if (len > 0) {
802 char firstChar = s.charAt(0);
803 if (firstChar == '-') {
804 throw new
805 NumberFormatException(String.format("Illegal leading minus sign " +
806 "on unsigned string %s.", s));
807 } else {
808 if (len <= 12 || // Long.MAX_VALUE in Character.MAX_RADIX is 13 digits
809 (radix == 10 && len <= 18) ) { // Long.MAX_VALUE in base 10 is 19 digits
810 return parseLong(s, radix);
811 }
812
813 // No need for range checks on len due to testing above.
814 long first = parseLong(s, radix, 0, len - 1);
815 int second = Character.digit(s.charAt(len - 1), radix);
816 if (second < 0) {
817 throw new NumberFormatException("Bad digit at end of " + s);
818 }
819 long result = first * radix + second;
820 if (compareUnsigned(result, first) < 0) {
821 /*
822 * The maximum unsigned value, (2^64)-1, takes at
823 * most one more digit to represent than the
824 * maximum signed value, (2^63)-1. Therefore,
825 * parsing (len - 1) digits will be appropriately
826 * in-range of the signed parsing. In other
827 * words, if parsing (len -1) digits overflows
828 * signed parsing, parsing len digits will
829 * certainly overflow unsigned parsing.
830 *
831 * The compareUnsigned check above catches
832 * situations where an unsigned overflow occurs
833 * incorporating the contribution of the final
834 * digit.
835 */
836 throw new NumberFormatException(String.format("String value %s exceeds " +
837 "range of unsigned long.", s));
838 }
839 return result;
840 }
841 } else {
842 throw NumberFormatException.forInputString(s);
843 }
844 }
845
846 /**
847 * Parses the {@link CharSequence} argument as an unsigned {@code long} in
848 * the specified {@code radix}, beginning at the specified
849 * {@code beginIndex} and extending to the end of the sequence.
850 *
851 * <p>The method does not take steps to guard against the
852 * {@code CharSequence} being mutated while parsing.
853 *
854 * @param s the {@code CharSequence} containing the unsigned
855 * {@code long} representation to be parsed
856 * @param radix the radix to be used while parsing {@code s}.
857 * @param beginIndex the beginning index, inclusive.
858 * @return the unsigned {@code long} represented by the subsequence in
859 * the specified radix.
860 * @throws NullPointerException if {@code s} is null.
861 * @throws IndexOutOfBoundsException if {@code beginIndex} is
862 * negative, or if {@code beginIndex} is greater than
863 * {@code s.length()}.
864 * @throws NumberFormatException if the {@code CharSequence} does not
865 * contain a parsable unsigned {@code long} in the specified
866 * {@code radix}, or if {@code radix} is either smaller than
867 * {@link java.lang.Character#MIN_RADIX} or larger than
868 * {@link java.lang.Character#MAX_RADIX}.
869 * @since 1.9
870 */
871 static long parseUnsignedLong(CharSequence s, int radix, int beginIndex)
872 throws NumberFormatException {
873 // forces a null check of s
874 return parseUnsignedLong(s, radix, beginIndex, s.length());
875 }
876
877 /**
878 * Parses the {@link CharSequence} argument as an unsigned {@code long} in
879 * the specified {@code radix}, beginning at the specified
880 * {@code beginIndex} and extending to {@code endIndex - 1}.
881 *
882 * <p>The method does not take steps to guard against the
883 * {@code CharSequence} being mutated while parsing.
884 *
885 * @param s the {@code CharSequence} containing the unsigned
886 * {@code long} representation to be parsed
887 * @param radix the radix to be used while parsing {@code s}.
888 * @param beginIndex the beginning index, inclusive.
889 * @param endIndex the ending index, exclusive.
890 * @return the unsigned {@code long} represented by the subsequence in
891 * the specified radix.
892 * @throws NullPointerException if {@code s} is null.
893 * @throws IndexOutOfBoundsException if {@code beginIndex} is
894 * negative, or if {@code beginIndex} is greater than
895 * {@code endIndex} or if {@code endIndex} is greater than
896 * {@code s.length()}.
897 * @throws NumberFormatException if the {@code CharSequence} does not
898 * contain a parsable unsigned {@code long} in the specified
899 * {@code radix}, or if {@code radix} is either smaller than
900 * {@link java.lang.Character#MIN_RADIX} or larger than
901 * {@link java.lang.Character#MAX_RADIX}.
902 * @since 1.9
903 */
904 static long parseUnsignedLong(CharSequence s, int radix, int beginIndex, int endIndex)
905 throws NumberFormatException {
906 s = Objects.requireNonNull(s);
907
908 if (beginIndex < 0 || beginIndex > endIndex || endIndex > s.length()) {
909 throw new IndexOutOfBoundsException();
910 }
911 int start = beginIndex, len = endIndex - beginIndex;
912
913 if (len > 0) {
914 char firstChar = s.charAt(start);
915 if (firstChar == '-') {
916 throw new NumberFormatException(String.format("Illegal leading minus sign " +
917 "on unsigned string %s.", s.subSequence(start, start + len)));
918 } else {
919 if (len <= 12 || // Long.MAX_VALUE in Character.MAX_RADIX is 13 digits
920 (radix == 10 && len <= 18) ) { // Long.MAX_VALUE in base 10 is 19 digits
921 return parseLong(s, radix, start, start + len);
922 }
923
924 // No need for range checks on end due to testing above.
925 long first = parseLong(s, radix, start, start + len - 1);
926 int second = Character.digit(s.charAt(start + len - 1), radix);
927 if (second < 0) {
928 throw new NumberFormatException("Bad digit at end of " +
929 s.subSequence(start, start + len));
930 }
931 long result = first * radix + second;
932
933 /*
934 * Test leftmost bits of multiprecision extension of first*radix
935 * for overflow. The number of bits needed is defined by
936 * GUARD_BIT = ceil(log2(Character.MAX_RADIX)) + 1 = 7. Then
937 * int guard = radix*(int)(first >>> (64 - GUARD_BIT)) and
938 * overflow is tested by splitting guard in the ranges
939 * guard < 92, 92 <= guard < 128, and 128 <= guard, where
940 * 92 = 128 - Character.MAX_RADIX. Note that guard cannot take
941 * on a value which does not include a prime factor in the legal
942 * radix range.
943 */
944 int guard = radix * (int) (first >>> 57);
945 if (guard >= 128 ||
946 (result >= 0 && guard >= 128 - Character.MAX_RADIX)) {
947 /*
948 * For purposes of exposition, the programmatic statements
949 * below should be taken to be multi-precision, i.e., not
950 * subject to overflow.
951 *
952 * A) Condition guard >= 128:
953 * If guard >= 128 then first*radix >= 2^7 * 2^57 = 2^64
954 * hence always overflow.
955 *
956 * B) Condition guard < 92:
957 * Define left7 = first >>> 57.
958 * Given first = (left7 * 2^57) + (first & (2^57 - 1)) then
959 * result <= (radix*left7)*2^57 + radix*(2^57 - 1) + second.
960 * Thus if radix*left7 < 92, radix <= 36, and second < 36,
961 * then result < 92*2^57 + 36*(2^57 - 1) + 36 = 2^64 hence
962 * never overflow.
963 *
964 * C) Condition 92 <= guard < 128:
965 * first*radix + second >= radix*left7*2^57 + second
966 * so that first*radix + second >= 92*2^57 + 0 > 2^63
967 *
968 * D) Condition guard < 128:
969 * radix*first <= (radix*left7) * 2^57 + radix*(2^57 - 1)
970 * so
971 * radix*first + second <= (radix*left7) * 2^57 + radix*(2^57 - 1) + 36
972 * thus
973 * radix*first + second < 128 * 2^57 + 36*2^57 - radix + 36
974 * whence
975 * radix*first + second < 2^64 + 2^6*2^57 = 2^64 + 2^63
976 *
977 * E) Conditions C, D, and result >= 0:
978 * C and D combined imply the mathematical result
979 * 2^63 < first*radix + second < 2^64 + 2^63. The lower
980 * bound is therefore negative as a signed long, but the
981 * upper bound is too small to overflow again after the
982 * signed long overflows to positive above 2^64 - 1. Hence
983 * result >= 0 implies overflow given C and D.
984 */
985 throw new NumberFormatException(String.format("String value %s exceeds " +
986 "range of unsigned long.", s.subSequence(start, start + len)));
987 }
988 return result;
989 }
990 } else {
991 throw NumberFormatException.forInputString("");
992 }
993 }
994
995 /**
996 * Parses the string argument as an unsigned decimal {@code long}. The
997 * characters in the string must all be decimal digits, except
998 * that the first character may be an an ASCII plus sign {@code
999 * '+'} ({@code '\u005Cu002B'}). The resulting integer value
1000 * is returned, exactly as if the argument and the radix 10 were
1001 * given as arguments to the {@link
1002 * #parseUnsignedLong(java.lang.String, int)} method.
1003 *
1004 * @param s a {@code String} containing the unsigned {@code long}
1005 * representation to be parsed
1006 * @return the unsigned {@code long} value represented by the decimal string argument
1007 * @throws NumberFormatException if the string does not contain a
1008 * parsable unsigned integer.
1009 * @since 1.8
1010 */
1011 public static long parseUnsignedLong(String s) throws NumberFormatException {
1012 return parseUnsignedLong(s, 10);
1013 }
1014
1015 /**
1016 * Returns a {@code Long} object holding the value
1017 * extracted from the specified {@code String} when parsed
1018 * with the radix given by the second argument. The first
1019 * argument is interpreted as representing a signed
1020 * {@code long} in the radix specified by the second
1021 * argument, exactly as if the arguments were given to the {@link
1022 * #parseLong(java.lang.String, int)} method. The result is a
1023 * {@code Long} object that represents the {@code long}
1024 * value specified by the string.
1025 *
1026 * <p>In other words, this method returns a {@code Long} object equal
1027 * to the value of:
1028 *
1029 * <blockquote>
1030 * {@code new Long(Long.parseLong(s, radix))}
1031 * </blockquote>
1032 *
1033 * @param s the string to be parsed
1034 * @param radix the radix to be used in interpreting {@code s}
1035 * @return a {@code Long} object holding the value
1036 * represented by the string argument in the specified
1037 * radix.
1038 * @throws NumberFormatException If the {@code String} does not
1039 * contain a parsable {@code long}.
1040 */
1041 public static Long valueOf(String s, int radix) throws NumberFormatException {
1042 return Long.valueOf(parseLong(s, radix));
1043 }
1044
1045 /**
1046 * Returns a {@code Long} object holding the value
1047 * of the specified {@code String}. The argument is
1048 * interpreted as representing a signed decimal {@code long},
1049 * exactly as if the argument were given to the {@link
1050 * #parseLong(java.lang.String)} method. The result is a
1051 * {@code Long} object that represents the integer value
1052 * specified by the string.
1053 *
1054 * <p>In other words, this method returns a {@code Long} object
1055 * equal to the value of:
1056 *
1057 * <blockquote>
1058 * {@code new Long(Long.parseLong(s))}
1059 * </blockquote>
1060 *
1061 * @param s the string to be parsed.
1062 * @return a {@code Long} object holding the value
1063 * represented by the string argument.
1064 * @throws NumberFormatException If the string cannot be parsed
1065 * as a {@code long}.
1066 */
1067 public static Long valueOf(String s) throws NumberFormatException
1068 {
1069 return Long.valueOf(parseLong(s, 10));
1070 }
1071
1072 private static class LongCache {
1073 private LongCache(){}
1074
1075 static final Long cache[] = new Long[-(-128) + 127 + 1];
1076
1077 static {
1078 for(int i = 0; i < cache.length; i++)
1079 cache[i] = new Long(i - 128);
1080 }
1081 }
1082
1083 /**
1084 * Returns a {@code Long} instance representing the specified
1085 * {@code long} value.
1086 * If a new {@code Long} instance is not required, this method
1087 * should generally be used in preference to the constructor
1088 * {@link #Long(long)}, as this method is likely to yield
1089 * significantly better space and time performance by caching
1090 * frequently requested values.
1091 *
1092 * Note that unlike the {@linkplain Integer#valueOf(int)
1093 * corresponding method} in the {@code Integer} class, this method
1094 * is <em>not</em> required to cache values within a particular
1095 * range.
1096 *
1097 * @param l a long value.
1098 * @return a {@code Long} instance representing {@code l}.
1099 * @since 1.5
1100 */
1101 public static Long valueOf(long l) {
1102 final int offset = 128;
1103 if (l >= -128 && l <= 127) { // will cache
1104 return LongCache.cache[(int)l + offset];
1105 }
1106 return new Long(l);
1107 }
1108
1109 /**
1110 * Decodes a {@code String} into a {@code Long}.
1111 * Accepts decimal, hexadecimal, and octal numbers given by the
1112 * following grammar:
1113 *
1114 * <blockquote>
1115 * <dl>
1116 * <dt><i>DecodableString:</i>
1117 * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i>
1118 * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i>
1119 * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i>
1120 * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i>
1121 * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i>
1122 *
1123 * <dt><i>Sign:</i>
1124 * <dd>{@code -}
1125 * <dd>{@code +}
1126 * </dl>
1127 * </blockquote>
1128 *
1129 * <i>DecimalNumeral</i>, <i>HexDigits</i>, and <i>OctalDigits</i>
1130 * are as defined in section 3.10.1 of
1131 * <cite>The Java™ Language Specification</cite>,
1132 * except that underscores are not accepted between digits.
1133 *
1134 * <p>The sequence of characters following an optional
1135 * sign and/or radix specifier ("{@code 0x}", "{@code 0X}",
1136 * "{@code #}", or leading zero) is parsed as by the {@code
1137 * Long.parseLong} method with the indicated radix (10, 16, or 8).
1138 * This sequence of characters must represent a positive value or
1139 * a {@link NumberFormatException} will be thrown. The result is
1140 * negated if first character of the specified {@code String} is
1141 * the minus sign. No whitespace characters are permitted in the
1142 * {@code String}.
1143 *
1144 * @param nm the {@code String} to decode.
1145 * @return a {@code Long} object holding the {@code long}
1146 * value represented by {@code nm}
1147 * @throws NumberFormatException if the {@code String} does not
1148 * contain a parsable {@code long}.
1149 * @see java.lang.Long#parseLong(String, int)
1150 * @since 1.2
1151 */
1152 public static Long decode(String nm) throws NumberFormatException {
1153 int radix = 10;
1154 int index = 0;
1155 boolean negative = false;
1156 Long result;
1157
1158 if (nm.length() == 0)
1159 throw new NumberFormatException("Zero length string");
1160 char firstChar = nm.charAt(0);
1161 // Handle sign, if present
1162 if (firstChar == '-') {
1163 negative = true;
1164 index++;
1165 } else if (firstChar == '+')
1166 index++;
1167
1168 // Handle radix specifier, if present
1169 if (nm.startsWith("0x", index) || nm.startsWith("0X", index)) {
1170 index += 2;
1171 radix = 16;
1172 }
1173 else if (nm.startsWith("#", index)) {
1174 index ++;
1175 radix = 16;
1176 }
1177 else if (nm.startsWith("0", index) && nm.length() > 1 + index) {
1178 index ++;
1179 radix = 8;
1180 }
1181
1182 if (nm.startsWith("-", index) || nm.startsWith("+", index))
1183 throw new NumberFormatException("Sign character in wrong position");
1184
1185 try {
1186 result = Long.valueOf(nm.substring(index), radix);
1187 result = negative ? Long.valueOf(-result.longValue()) : result;
1188 } catch (NumberFormatException e) {
1189 // If number is Long.MIN_VALUE, we'll end up here. The next line
1190 // handles this case, and causes any genuine format error to be
1191 // rethrown.
1192 String constant = negative ? ("-" + nm.substring(index))
1193 : nm.substring(index);
1194 result = Long.valueOf(constant, radix);
1195 }
1196 return result;
1197 }
1198
1199 /**
1200 * The value of the {@code Long}.
1201 *
1202 * @serial
1203 */
1204 private final long value;
1205
1206 /**
1207 * Constructs a newly allocated {@code Long} object that
1208 * represents the specified {@code long} argument.
1209 *
1210 * @param value the value to be represented by the
1211 * {@code Long} object.
1212 */
1213 public Long(long value) {
1214 this.value = value;
1215 }
1216
1217 /**
1218 * Constructs a newly allocated {@code Long} object that
1219 * represents the {@code long} value indicated by the
1220 * {@code String} parameter. The string is converted to a
1221 * {@code long} value in exactly the manner used by the
1222 * {@code parseLong} method for radix 10.
1223 *
1224 * @param s the {@code String} to be converted to a
1225 * {@code Long}.
1226 * @throws NumberFormatException if the {@code String} does not
1227 * contain a parsable {@code long}.
1228 * @see java.lang.Long#parseLong(java.lang.String, int)
1229 */
1230 public Long(String s) throws NumberFormatException {
1231 this.value = parseLong(s, 10);
1232 }
1233
1234 /**
1235 * Returns the value of this {@code Long} as a {@code byte} after
1236 * a narrowing primitive conversion.
1237 * @jls 5.1.3 Narrowing Primitive Conversions
1238 */
1239 public byte byteValue() {
1240 return (byte)value;
1241 }
1242
1243 /**
1244 * Returns the value of this {@code Long} as a {@code short} after
1245 * a narrowing primitive conversion.
1246 * @jls 5.1.3 Narrowing Primitive Conversions
1247 */
1248 public short shortValue() {
1249 return (short)value;
1250 }
1251
1252 /**
1253 * Returns the value of this {@code Long} as an {@code int} after
1254 * a narrowing primitive conversion.
1255 * @jls 5.1.3 Narrowing Primitive Conversions
1256 */
1257 public int intValue() {
1258 return (int)value;
1259 }
1260
1261 /**
1262 * Returns the value of this {@code Long} as a
1263 * {@code long} value.
1264 */
1265 public long longValue() {
1266 return value;
1267 }
1268
1269 /**
1270 * Returns the value of this {@code Long} as a {@code float} after
1271 * a widening primitive conversion.
1272 * @jls 5.1.2 Widening Primitive Conversions
1273 */
1274 public float floatValue() {
1275 return (float)value;
1276 }
1277
1278 /**
1279 * Returns the value of this {@code Long} as a {@code double}
1280 * after a widening primitive conversion.
1281 * @jls 5.1.2 Widening Primitive Conversions
1282 */
1283 public double doubleValue() {
1284 return (double)value;
1285 }
1286
1287 /**
1288 * Returns a {@code String} object representing this
1289 * {@code Long}'s value. The value is converted to signed
1290 * decimal representation and returned as a string, exactly as if
1291 * the {@code long} value were given as an argument to the
1292 * {@link java.lang.Long#toString(long)} method.
1293 *
1294 * @return a string representation of the value of this object in
1295 * base 10.
1296 */
1297 public String toString() {
1298 return toString(value);
1299 }
1300
1301 /**
1302 * Returns a hash code for this {@code Long}. The result is
1303 * the exclusive OR of the two halves of the primitive
1304 * {@code long} value held by this {@code Long}
1305 * object. That is, the hashcode is the value of the expression:
1306 *
1307 * <blockquote>
1308 * {@code (int)(this.longValue()^(this.longValue()>>>32))}
1309 * </blockquote>
1310 *
1311 * @return a hash code value for this object.
1312 */
1313 @Override
1314 public int hashCode() {
1315 return Long.hashCode(value);
1316 }
1317
1318 /**
1319 * Returns a hash code for a {@code long} value; compatible with
1320 * {@code Long.hashCode()}.
1321 *
1322 * @param value the value to hash
1323 * @return a hash code value for a {@code long} value.
1324 * @since 1.8
1325 */
1326 public static int hashCode(long value) {
1327 return (int)(value ^ (value >>> 32));
1328 }
1329
1330 /**
1331 * Compares this object to the specified object. The result is
1332 * {@code true} if and only if the argument is not
1333 * {@code null} and is a {@code Long} object that
1334 * contains the same {@code long} value as this object.
1335 *
1336 * @param obj the object to compare with.
1337 * @return {@code true} if the objects are the same;
1338 * {@code false} otherwise.
1339 */
1340 public boolean equals(Object obj) {
1341 if (obj instanceof Long) {
1342 return value == ((Long)obj).longValue();
1343 }
1344 return false;
1345 }
1346
1347 /**
1348 * Determines the {@code long} value of the system property
1349 * with the specified name.
1350 *
1351 * <p>The first argument is treated as the name of a system
1352 * property. System properties are accessible through the {@link
1353 * java.lang.System#getProperty(java.lang.String)} method. The
1354 * string value of this property is then interpreted as a {@code
1355 * long} value using the grammar supported by {@link Long#decode decode}
1356 * and a {@code Long} object representing this value is returned.
1357 *
1358 * <p>If there is no property with the specified name, if the
1359 * specified name is empty or {@code null}, or if the property
1360 * does not have the correct numeric format, then {@code null} is
1361 * returned.
1362 *
1363 * <p>In other words, this method returns a {@code Long} object
1364 * equal to the value of:
1365 *
1366 * <blockquote>
1367 * {@code getLong(nm, null)}
1368 * </blockquote>
1369 *
1370 * @param nm property name.
1371 * @return the {@code Long} value of the property.
1372 * @throws SecurityException for the same reasons as
1373 * {@link System#getProperty(String) System.getProperty}
1374 * @see java.lang.System#getProperty(java.lang.String)
1375 * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
1376 */
1377 public static Long getLong(String nm) {
1378 return getLong(nm, null);
1379 }
1380
1381 /**
1382 * Determines the {@code long} value of the system property
1383 * with the specified name.
1384 *
1385 * <p>The first argument is treated as the name of a system
1386 * property. System properties are accessible through the {@link
1387 * java.lang.System#getProperty(java.lang.String)} method. The
1388 * string value of this property is then interpreted as a {@code
1389 * long} value using the grammar supported by {@link Long#decode decode}
1390 * and a {@code Long} object representing this value is returned.
1391 *
1392 * <p>The second argument is the default value. A {@code Long} object
1393 * that represents the value of the second argument is returned if there
1394 * is no property of the specified name, if the property does not have
1395 * the correct numeric format, or if the specified name is empty or null.
1396 *
1397 * <p>In other words, this method returns a {@code Long} object equal
1398 * to the value of:
1399 *
1400 * <blockquote>
1401 * {@code getLong(nm, new Long(val))}
1402 * </blockquote>
1403 *
1404 * but in practice it may be implemented in a manner such as:
1405 *
1406 * <blockquote><pre>
1407 * Long result = getLong(nm, null);
1408 * return (result == null) ? new Long(val) : result;
1409 * </pre></blockquote>
1410 *
1411 * to avoid the unnecessary allocation of a {@code Long} object when
1412 * the default value is not needed.
1413 *
1414 * @param nm property name.
1415 * @param val default value.
1416 * @return the {@code Long} value of the property.
1417 * @throws SecurityException for the same reasons as
1418 * {@link System#getProperty(String) System.getProperty}
1419 * @see java.lang.System#getProperty(java.lang.String)
1420 * @see java.lang.System#getProperty(java.lang.String, java.lang.String)
1421 */
1422 public static Long getLong(String nm, long val) {
1423 Long result = Long.getLong(nm, null);
1424 return (result == null) ? Long.valueOf(val) : result;
1425 }
1426
1427 /**
1428 * Returns the {@code long} value of the system property with
1429 * the specified name. The first argument is treated as the name
1430 * of a system property. System properties are accessible through
1431 * the {@link java.lang.System#getProperty(java.lang.String)}
1432 * method. The string value of this property is then interpreted
1433 * as a {@code long} value, as per the
1434 * {@link Long#decode decode} method, and a {@code Long} object
1435 * representing this value is returned; in summary:
1436 *
1437 * <ul>
1438 * <li>If the property value begins with the two ASCII characters
1439 * {@code 0x} or the ASCII character {@code #}, not followed by
1440 * a minus sign, then the rest of it is parsed as a hexadecimal integer
1441 * exactly as for the method {@link #valueOf(java.lang.String, int)}
1442 * with radix 16.
1443 * <li>If the property value begins with the ASCII character
1444 * {@code 0} followed by another character, it is parsed as
1445 * an octal integer exactly as by the method {@link
1446 * #valueOf(java.lang.String, int)} with radix 8.
1447 * <li>Otherwise the property value is parsed as a decimal
1448 * integer exactly as by the method
1449 * {@link #valueOf(java.lang.String, int)} with radix 10.
1450 * </ul>
1451 *
1452 * <p>Note that, in every case, neither {@code L}
1453 * ({@code '\u005Cu004C'}) nor {@code l}
1454 * ({@code '\u005Cu006C'}) is permitted to appear at the end
1455 * of the property value as a type indicator, as would be
1456 * permitted in Java programming language source code.
1457 *
1458 * <p>The second argument is the default value. The default value is
1459 * returned if there is no property of the specified name, if the
1460 * property does not have the correct numeric format, or if the
1461 * specified name is empty or {@code null}.
1462 *
1463 * @param nm property name.
1464 * @param val default value.
1465 * @return the {@code Long} value of the property.
1466 * @throws SecurityException for the same reasons as
1467 * {@link System#getProperty(String) System.getProperty}
1468 * @see System#getProperty(java.lang.String)
1469 * @see System#getProperty(java.lang.String, java.lang.String)
1470 */
1471 public static Long getLong(String nm, Long val) {
1472 String v = null;
1473 try {
1474 v = System.getProperty(nm);
1475 } catch (IllegalArgumentException | NullPointerException e) {
1476 }
1477 if (v != null) {
1478 try {
1479 return Long.decode(v);
1480 } catch (NumberFormatException e) {
1481 }
1482 }
1483 return val;
1484 }
1485
1486 /**
1487 * Compares two {@code Long} objects numerically.
1488 *
1489 * @param anotherLong the {@code Long} to be compared.
1490 * @return the value {@code 0} if this {@code Long} is
1491 * equal to the argument {@code Long}; a value less than
1492 * {@code 0} if this {@code Long} is numerically less
1493 * than the argument {@code Long}; and a value greater
1494 * than {@code 0} if this {@code Long} is numerically
1495 * greater than the argument {@code Long} (signed
1496 * comparison).
1497 * @since 1.2
1498 */
1499 public int compareTo(Long anotherLong) {
1500 return compare(this.value, anotherLong.value);
1501 }
1502
1503 /**
1504 * Compares two {@code long} values numerically.
1505 * The value returned is identical to what would be returned by:
1506 * <pre>
1507 * Long.valueOf(x).compareTo(Long.valueOf(y))
1508 * </pre>
1509 *
1510 * @param x the first {@code long} to compare
1511 * @param y the second {@code long} to compare
1512 * @return the value {@code 0} if {@code x == y};
1513 * a value less than {@code 0} if {@code x < y}; and
1514 * a value greater than {@code 0} if {@code x > y}
1515 * @since 1.7
1516 */
1517 public static int compare(long x, long y) {
1518 return (x < y) ? -1 : ((x == y) ? 0 : 1);
1519 }
1520
1521 /**
1522 * Compares two {@code long} values numerically treating the values
1523 * as unsigned.
1524 *
1525 * @param x the first {@code long} to compare
1526 * @param y the second {@code long} to compare
1527 * @return the value {@code 0} if {@code x == y}; a value less
1528 * than {@code 0} if {@code x < y} as unsigned values; and
1529 * a value greater than {@code 0} if {@code x > y} as
1530 * unsigned values
1531 * @since 1.8
1532 */
1533 public static int compareUnsigned(long x, long y) {
1534 return compare(x + MIN_VALUE, y + MIN_VALUE);
1535 }
1536
1537
1538 /**
1539 * Returns the unsigned quotient of dividing the first argument by
1540 * the second where each argument and the result is interpreted as
1541 * an unsigned value.
1542 *
1543 * <p>Note that in two's complement arithmetic, the three other
1544 * basic arithmetic operations of add, subtract, and multiply are
1545 * bit-wise identical if the two operands are regarded as both
1546 * being signed or both being unsigned. Therefore separate {@code
1547 * addUnsigned}, etc. methods are not provided.
1548 *
1549 * @param dividend the value to be divided
1550 * @param divisor the value doing the dividing
1551 * @return the unsigned quotient of the first argument divided by
1552 * the second argument
1553 * @see #remainderUnsigned
1554 * @since 1.8
1555 */
1556 public static long divideUnsigned(long dividend, long divisor) {
1557 if (divisor < 0L) { // signed comparison
1558 // Answer must be 0 or 1 depending on relative magnitude
1559 // of dividend and divisor.
1560 return (compareUnsigned(dividend, divisor)) < 0 ? 0L :1L;
1561 }
1562
1563 if (dividend > 0) // Both inputs non-negative
1564 return dividend/divisor;
1565 else {
1566 /*
1567 * For simple code, leveraging BigInteger. Longer and faster
1568 * code written directly in terms of operations on longs is
1569 * possible; see "Hacker's Delight" for divide and remainder
1570 * algorithms.
1571 */
1572 return toUnsignedBigInteger(dividend).
1573 divide(toUnsignedBigInteger(divisor)).longValue();
1574 }
1575 }
1576
1577 /**
1578 * Returns the unsigned remainder from dividing the first argument
1579 * by the second where each argument and the result is interpreted
1580 * as an unsigned value.
1581 *
1582 * @param dividend the value to be divided
1583 * @param divisor the value doing the dividing
1584 * @return the unsigned remainder of the first argument divided by
1585 * the second argument
1586 * @see #divideUnsigned
1587 * @since 1.8
1588 */
1589 public static long remainderUnsigned(long dividend, long divisor) {
1590 if (dividend > 0 && divisor > 0) { // signed comparisons
1591 return dividend % divisor;
1592 } else {
1593 if (compareUnsigned(dividend, divisor) < 0) // Avoid explicit check for 0 divisor
1594 return dividend;
1595 else
1596 return toUnsignedBigInteger(dividend).
1597 remainder(toUnsignedBigInteger(divisor)).longValue();
1598 }
1599 }
1600
1601 // Bit Twiddling
1602
1603 /**
1604 * The number of bits used to represent a {@code long} value in two's
1605 * complement binary form.
1606 *
1607 * @since 1.5
1608 */
1609 @Native public static final int SIZE = 64;
1610
1611 /**
1612 * The number of bytes used to represent a {@code long} value in two's
1613 * complement binary form.
1614 *
1615 * @since 1.8
1616 */
1617 public static final int BYTES = SIZE / Byte.SIZE;
1618
1619 /**
1620 * Returns a {@code long} value with at most a single one-bit, in the
1621 * position of the highest-order ("leftmost") one-bit in the specified
1622 * {@code long} value. Returns zero if the specified value has no
1623 * one-bits in its two's complement binary representation, that is, if it
1624 * is equal to zero.
1625 *
1626 * @param i the value whose highest one bit is to be computed
1627 * @return a {@code long} value with a single one-bit, in the position
1628 * of the highest-order one-bit in the specified value, or zero if
1629 * the specified value is itself equal to zero.
1630 * @since 1.5
1631 */
1632 public static long highestOneBit(long i) {
1633 // HD, Figure 3-1
1634 i |= (i >> 1);
1635 i |= (i >> 2);
1636 i |= (i >> 4);
1637 i |= (i >> 8);
1638 i |= (i >> 16);
1639 i |= (i >> 32);
1640 return i - (i >>> 1);
1641 }
1642
1643 /**
1644 * Returns a {@code long} value with at most a single one-bit, in the
1645 * position of the lowest-order ("rightmost") one-bit in the specified
1646 * {@code long} value. Returns zero if the specified value has no
1647 * one-bits in its two's complement binary representation, that is, if it
1648 * is equal to zero.
1649 *
1650 * @param i the value whose lowest one bit is to be computed
1651 * @return a {@code long} value with a single one-bit, in the position
1652 * of the lowest-order one-bit in the specified value, or zero if
1653 * the specified value is itself equal to zero.
1654 * @since 1.5
1655 */
1656 public static long lowestOneBit(long i) {
1657 // HD, Section 2-1
1658 return i & -i;
1659 }
1660
1661 /**
1662 * Returns the number of zero bits preceding the highest-order
1663 * ("leftmost") one-bit in the two's complement binary representation
1664 * of the specified {@code long} value. Returns 64 if the
1665 * specified value has no one-bits in its two's complement representation,
1666 * in other words if it is equal to zero.
1667 *
1668 * <p>Note that this method is closely related to the logarithm base 2.
1669 * For all positive {@code long} values x:
1670 * <ul>
1671 * <li>floor(log<sub>2</sub>(x)) = {@code 63 - numberOfLeadingZeros(x)}
1672 * <li>ceil(log<sub>2</sub>(x)) = {@code 64 - numberOfLeadingZeros(x - 1)}
1673 * </ul>
1674 *
1675 * @param i the value whose number of leading zeros is to be computed
1676 * @return the number of zero bits preceding the highest-order
1677 * ("leftmost") one-bit in the two's complement binary representation
1678 * of the specified {@code long} value, or 64 if the value
1679 * is equal to zero.
1680 * @since 1.5
1681 */
1682 public static int numberOfLeadingZeros(long i) {
1683 // HD, Figure 5-6
1684 if (i == 0)
1685 return 64;
1686 int n = 1;
1687 int x = (int)(i >>> 32);
1688 if (x == 0) { n += 32; x = (int)i; }
1689 if (x >>> 16 == 0) { n += 16; x <<= 16; }
1690 if (x >>> 24 == 0) { n += 8; x <<= 8; }
1691 if (x >>> 28 == 0) { n += 4; x <<= 4; }
1692 if (x >>> 30 == 0) { n += 2; x <<= 2; }
1693 n -= x >>> 31;
1694 return n;
1695 }
1696
1697 /**
1698 * Returns the number of zero bits following the lowest-order ("rightmost")
1699 * one-bit in the two's complement binary representation of the specified
1700 * {@code long} value. Returns 64 if the specified value has no
1701 * one-bits in its two's complement representation, in other words if it is
1702 * equal to zero.
1703 *
1704 * @param i the value whose number of trailing zeros is to be computed
1705 * @return the number of zero bits following the lowest-order ("rightmost")
1706 * one-bit in the two's complement binary representation of the
1707 * specified {@code long} value, or 64 if the value is equal
1708 * to zero.
1709 * @since 1.5
1710 */
1711 public static int numberOfTrailingZeros(long i) {
1712 // HD, Figure 5-14
1713 int x, y;
1714 if (i == 0) return 64;
1715 int n = 63;
1716 y = (int)i; if (y != 0) { n = n -32; x = y; } else x = (int)(i>>>32);
1717 y = x <<16; if (y != 0) { n = n -16; x = y; }
1718 y = x << 8; if (y != 0) { n = n - 8; x = y; }
1719 y = x << 4; if (y != 0) { n = n - 4; x = y; }
1720 y = x << 2; if (y != 0) { n = n - 2; x = y; }
1721 return n - ((x << 1) >>> 31);
1722 }
1723
1724 /**
1725 * Returns the number of one-bits in the two's complement binary
1726 * representation of the specified {@code long} value. This function is
1727 * sometimes referred to as the <i>population count</i>.
1728 *
1729 * @param i the value whose bits are to be counted
1730 * @return the number of one-bits in the two's complement binary
1731 * representation of the specified {@code long} value.
1732 * @since 1.5
1733 */
1734 public static int bitCount(long i) {
1735 // HD, Figure 5-14
1736 i = i - ((i >>> 1) & 0x5555555555555555L);
1737 i = (i & 0x3333333333333333L) + ((i >>> 2) & 0x3333333333333333L);
1738 i = (i + (i >>> 4)) & 0x0f0f0f0f0f0f0f0fL;
1739 i = i + (i >>> 8);
1740 i = i + (i >>> 16);
1741 i = i + (i >>> 32);
1742 return (int)i & 0x7f;
1743 }
1744
1745 /**
1746 * Returns the value obtained by rotating the two's complement binary
1747 * representation of the specified {@code long} value left by the
1748 * specified number of bits. (Bits shifted out of the left hand, or
1749 * high-order, side reenter on the right, or low-order.)
1750 *
1751 * <p>Note that left rotation with a negative distance is equivalent to
1752 * right rotation: {@code rotateLeft(val, -distance) == rotateRight(val,
1753 * distance)}. Note also that rotation by any multiple of 64 is a
1754 * no-op, so all but the last six bits of the rotation distance can be
1755 * ignored, even if the distance is negative: {@code rotateLeft(val,
1756 * distance) == rotateLeft(val, distance & 0x3F)}.
1757 *
1758 * @param i the value whose bits are to be rotated left
1759 * @param distance the number of bit positions to rotate left
1760 * @return the value obtained by rotating the two's complement binary
1761 * representation of the specified {@code long} value left by the
1762 * specified number of bits.
1763 * @since 1.5
1764 */
1765 public static long rotateLeft(long i, int distance) {
1766 return (i << distance) | (i >>> -distance);
1767 }
1768
1769 /**
1770 * Returns the value obtained by rotating the two's complement binary
1771 * representation of the specified {@code long} value right by the
1772 * specified number of bits. (Bits shifted out of the right hand, or
1773 * low-order, side reenter on the left, or high-order.)
1774 *
1775 * <p>Note that right rotation with a negative distance is equivalent to
1776 * left rotation: {@code rotateRight(val, -distance) == rotateLeft(val,
1777 * distance)}. Note also that rotation by any multiple of 64 is a
1778 * no-op, so all but the last six bits of the rotation distance can be
1779 * ignored, even if the distance is negative: {@code rotateRight(val,
1780 * distance) == rotateRight(val, distance & 0x3F)}.
1781 *
1782 * @param i the value whose bits are to be rotated right
1783 * @param distance the number of bit positions to rotate right
1784 * @return the value obtained by rotating the two's complement binary
1785 * representation of the specified {@code long} value right by the
1786 * specified number of bits.
1787 * @since 1.5
1788 */
1789 public static long rotateRight(long i, int distance) {
1790 return (i >>> distance) | (i << -distance);
1791 }
1792
1793 /**
1794 * Returns the value obtained by reversing the order of the bits in the
1795 * two's complement binary representation of the specified {@code long}
1796 * value.
1797 *
1798 * @param i the value to be reversed
1799 * @return the value obtained by reversing order of the bits in the
1800 * specified {@code long} value.
1801 * @since 1.5
1802 */
1803 public static long reverse(long i) {
1804 // HD, Figure 7-1
1805 i = (i & 0x5555555555555555L) << 1 | (i >>> 1) & 0x5555555555555555L;
1806 i = (i & 0x3333333333333333L) << 2 | (i >>> 2) & 0x3333333333333333L;
1807 i = (i & 0x0f0f0f0f0f0f0f0fL) << 4 | (i >>> 4) & 0x0f0f0f0f0f0f0f0fL;
1808 i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;
1809 i = (i << 48) | ((i & 0xffff0000L) << 16) |
1810 ((i >>> 16) & 0xffff0000L) | (i >>> 48);
1811 return i;
1812 }
1813
1814 /**
1815 * Returns the signum function of the specified {@code long} value. (The
1816 * return value is -1 if the specified value is negative; 0 if the
1817 * specified value is zero; and 1 if the specified value is positive.)
1818 *
1819 * @param i the value whose signum is to be computed
1820 * @return the signum function of the specified {@code long} value.
1821 * @since 1.5
1822 */
1823 public static int signum(long i) {
1824 // HD, Section 2-7
1825 return (int) ((i >> 63) | (-i >>> 63));
1826 }
1827
1828 /**
1829 * Returns the value obtained by reversing the order of the bytes in the
1830 * two's complement representation of the specified {@code long} value.
1831 *
1832 * @param i the value whose bytes are to be reversed
1833 * @return the value obtained by reversing the bytes in the specified
1834 * {@code long} value.
1835 * @since 1.5
1836 */
1837 public static long reverseBytes(long i) {
1838 i = (i & 0x00ff00ff00ff00ffL) << 8 | (i >>> 8) & 0x00ff00ff00ff00ffL;
1839 return (i << 48) | ((i & 0xffff0000L) << 16) |
1840 ((i >>> 16) & 0xffff0000L) | (i >>> 48);
1841 }
1842
1843 /**
1844 * Adds two {@code long} values together as per the + operator.
1845 *
1846 * @param a the first operand
1847 * @param b the second operand
1848 * @return the sum of {@code a} and {@code b}
1849 * @see java.util.function.BinaryOperator
1850 * @since 1.8
1851 */
1852 public static long sum(long a, long b) {
1853 return a + b;
1854 }
1855
1856 /**
1857 * Returns the greater of two {@code long} values
1858 * as if by calling {@link Math#max(long, long) Math.max}.
1859 *
1860 * @param a the first operand
1861 * @param b the second operand
1862 * @return the greater of {@code a} and {@code b}
1863 * @see java.util.function.BinaryOperator
1864 * @since 1.8
1865 */
1866 public static long max(long a, long b) {
1867 return Math.max(a, b);
1868 }
1869
1870 /**
1871 * Returns the smaller of two {@code long} values
1872 * as if by calling {@link Math#min(long, long) Math.min}.
1873 *
1874 * @param a the first operand
1875 * @param b the second operand
1876 * @return the smaller of {@code a} and {@code b}
1877 * @see java.util.function.BinaryOperator
1878 * @since 1.8
1879 */
1880 public static long min(long a, long b) {
1881 return Math.min(a, b);
1882 }
1883
1884 /** use serialVersionUID from JDK 1.0.2 for interoperability */
1885 @Native private static final long serialVersionUID = 4290774380558885855L;
1886 }