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src/java.base/share/classes/java/lang/Character.java

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rev 53050 : [mq]: 8215303


  26 package java.lang;
  27 
  28 import java.util.Arrays;
  29 import java.util.Map;
  30 import java.util.HashMap;
  31 import java.util.Locale;
  32 
  33 import jdk.internal.HotSpotIntrinsicCandidate;
  34 import jdk.internal.misc.VM;
  35 
  36 /**
  37  * The {@code Character} class wraps a value of the primitive
  38  * type {@code char} in an object. An object of type
  39  * {@code Character} contains a single field whose type is
  40  * {@code char}.
  41  * <p>
  42  * In addition, this class provides several methods for determining
  43  * a character's category (lowercase letter, digit, etc.) and for converting
  44  * characters from uppercase to lowercase and vice versa.
  45  * <p>
  46  * Character information is based on the Unicode Standard, version 11.0.0.


  47  * <p>
  48  * The methods and data of class {@code Character} are defined by
  49  * the information in the <i>UnicodeData</i> file that is part of the
  50  * Unicode Character Database maintained by the Unicode
  51  * Consortium. This file specifies various properties including name
  52  * and general category for every defined Unicode code point or
  53  * character range.
  54  * <p>
  55  * The file and its description are available from the Unicode Consortium at:
  56  * <ul>
  57  * <li><a href="http://www.unicode.org">http://www.unicode.org</a>
  58  * </ul>
  59  * <p>
  60  * The code point, U+32FF, is reserved by the Unicode Consortium
  61  * to represent the Japanese square character for the new era that begins
  62  * May 2019. Relevant methods in the Character class return the same
  63  * properties as for the existing Japanese era characters (e.g., U+337E for
  64  * "Meizi"). For the details of the code point, refer to
  65  * <a href="http://blog.unicode.org/2018/09/new-japanese-era.html">
  66  * http://blog.unicode.org/2018/09/new-japanese-era.html</a>.







  67  *
  68  * <h3><a id="unicode">Unicode Character Representations</a></h3>
  69  *
  70  * <p>The {@code char} data type (and therefore the value that a
  71  * {@code Character} object encapsulates) are based on the
  72  * original Unicode specification, which defined characters as
  73  * fixed-width 16-bit entities. The Unicode Standard has since been
  74  * changed to allow for characters whose representation requires more
  75  * than 16 bits.  The range of legal <em>code point</em>s is now
  76  * U+0000 to U+10FFFF, known as <em>Unicode scalar value</em>.
  77  * (Refer to the <a
  78  * href="http://www.unicode.org/reports/tr27/#notation"><i>
  79  * definition</i></a> of the U+<i>n</i> notation in the Unicode
  80  * Standard.)
  81  *
  82  * <p><a id="BMP">The set of characters from U+0000 to U+FFFF</a> is
  83  * sometimes referred to as the <em>Basic Multilingual Plane (BMP)</em>.
  84  * <a id="supplementary">Characters</a> whose code points are greater
  85  * than U+FFFF are called <em>supplementary character</em>s.  The Java
  86  * platform uses the UTF-16 representation in {@code char} arrays and




  26 package java.lang;
  27 
  28 import java.util.Arrays;
  29 import java.util.Map;
  30 import java.util.HashMap;
  31 import java.util.Locale;
  32 
  33 import jdk.internal.HotSpotIntrinsicCandidate;
  34 import jdk.internal.misc.VM;
  35 
  36 /**
  37  * The {@code Character} class wraps a value of the primitive
  38  * type {@code char} in an object. An object of type
  39  * {@code Character} contains a single field whose type is
  40  * {@code char}.
  41  * <p>
  42  * In addition, this class provides several methods for determining
  43  * a character's category (lowercase letter, digit, etc.) and for converting
  44  * characters from uppercase to lowercase and vice versa.
  45  * <p>
  46  * Character information is based on <a id="UnicodeVer">the Unicode Standard,
  47  * version 11.0.0</a>. Additional currency symbols (and Japanese Era Square
  48  * character) defined subsequent to that Unicode version may be present.
  49  * <p>
  50  * The methods and data of class {@code Character} are defined by
  51  * the information in the <i>UnicodeData</i> file that is part of the
  52  * Unicode Character Database maintained by the Unicode
  53  * Consortium. This file specifies various properties including name
  54  * and general category for every defined Unicode code point or
  55  * character range.
  56  * <p>
  57  * The file and its description are available from the Unicode Consortium at:
  58  * <ul>
  59  * <li><a href="http://www.unicode.org">http://www.unicode.org</a>
  60  * </ul>
  61  * <p>
  62  * The code point, U+32FF, is reserved by the Unicode Consortium
  63  * to represent the Japanese square character for the new era that begins
  64  * May 2019. Relevant methods in the Character class return the same
  65  * properties as for the existing Japanese era characters (e.g., U+337E for
  66  * "Meizi"). For the details of the code point, refer to
  67  * <a href="http://blog.unicode.org/2018/09/new-japanese-era.html">
  68  * http://blog.unicode.org/2018/09/new-japanese-era.html</a>.
  69  * <p>
  70  * @implSpec The code points in {@link Character.UnicodeBlock#CURRENCY_SYMBOLS
  71  * Currency Symbols} {@code UnicodeBlock} that are unassigned as of the
  72  * <a href="#UnicodeVer">Unicode version noted above</a>,
  73  * may be defined for currency symbols assigned by the Unicode
  74  * Consortium from later updates. The definition of additionally assigned
  75  * code points is implementation specific.
  76  *
  77  * <h3><a id="unicode">Unicode Character Representations</a></h3>
  78  *
  79  * <p>The {@code char} data type (and therefore the value that a
  80  * {@code Character} object encapsulates) are based on the
  81  * original Unicode specification, which defined characters as
  82  * fixed-width 16-bit entities. The Unicode Standard has since been
  83  * changed to allow for characters whose representation requires more
  84  * than 16 bits.  The range of legal <em>code point</em>s is now
  85  * U+0000 to U+10FFFF, known as <em>Unicode scalar value</em>.
  86  * (Refer to the <a
  87  * href="http://www.unicode.org/reports/tr27/#notation"><i>
  88  * definition</i></a> of the U+<i>n</i> notation in the Unicode
  89  * Standard.)
  90  *
  91  * <p><a id="BMP">The set of characters from U+0000 to U+FFFF</a> is
  92  * sometimes referred to as the <em>Basic Multilingual Plane (BMP)</em>.
  93  * <a id="supplementary">Characters</a> whose code points are greater
  94  * than U+FFFF are called <em>supplementary character</em>s.  The Java
  95  * platform uses the UTF-16 representation in {@code char} arrays and


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