Java(TM) 2 Platform, Standard Edition, v1.2.2 API Specification: Class Character - JDK 5 Documentation v1.2.2, Java 2 SDK 英文文档

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java.lang
Class Character

java.lang.Object
  |
  +--java.lang.Character

public final class Character
extends Object
implements Serializable, Comparable

The Character class wraps a value of the primitive type char in an object. An object of type Character contains a single field whose type is char.

In addition, this class provides several methods for determining the type of a character and converting characters from uppercase to lowercase and vice versa.

Many of the methods of class Character are defined in terms of a "Unicode attribute table" that specifies a name for every defined Unicode code point. The table also includes other attributes, such as a decimal value, an uppercase equivalent, a lowercase equivalent, and/or a titlecase equivalent. The character attribute tables for specific versions of Unicode are available on the World Wide Web in various subdirectories of:

   ftp://ftp.unicode.org/Public/

For a more detailed specification of the Character class, one that encompasses the exact behavior of methods such as isDigit, isLetter, isLowerCase, and isUpperCase over the full range of Unicode values, see Gosling, Joy, and Steele, The Java Language Specification.

Since:: JDK1.0
See Also:: Serialized Form

Inner Class Summary

static class Character.Subset
          Instances of this class represent particular subsets of the Unicode character set.

static class Character.UnicodeBlock
          A family of character subsets representing the character blocks defined by the Unicode 2.0 specification.

Field Summary

static byte COMBINING_SPACING_MARK
          Public data for enumerated Unicode general category types

static byte CONNECTOR_PUNCTUATION
          Public data for enumerated Unicode general category types

static byte CONTROL
          Public data for enumerated Unicode general category types

static byte CURRENCY_SYMBOL
          Public data for enumerated Unicode general category types

static byte DASH_PUNCTUATION
          Public data for enumerated Unicode general category types

static byte DECIMAL_DIGIT_NUMBER
          Public data for enumerated Unicode general category types

static byte ENCLOSING_MARK
          Public data for enumerated Unicode general category types

static byte END_PUNCTUATION
          Public data for enumerated Unicode general category types

static byte FORMAT
          Public data for enumerated Unicode general category types

static byte LETTER_NUMBER
          Public data for enumerated Unicode general category types

static byte LINE_SEPARATOR
          Public data for enumerated Unicode general category types

static byte LOWERCASE_LETTER
          Public data for enumerated Unicode general category types

static byte MATH_SYMBOL
          Public data for enumerated Unicode general category types

static int MAX_RADIX
          The maximum radix available for conversion to and from Strings.

static char MAX_VALUE
          The constant value of this field is the largest value of type char.

static int MIN_RADIX
          The minimum radix available for conversion to and from Strings.

static char MIN_VALUE
          The constant value of this field is the smallest value of type char.

static byte MODIFIER_LETTER
          Public data for enumerated Unicode general category types

static byte MODIFIER_SYMBOL
          Public data for enumerated Unicode general category types

static byte NON_SPACING_MARK
          Public data for enumerated Unicode general category types

static byte OTHER_LETTER
          Public data for enumerated Unicode general category types

static byte OTHER_NUMBER
          Public data for enumerated Unicode general category types

static byte OTHER_PUNCTUATION
          Public data for enumerated Unicode general category types

static byte OTHER_SYMBOL
          Public data for enumerated Unicode general category types

static byte PARAGRAPH_SEPARATOR
          Public data for enumerated Unicode general category types

static byte PRIVATE_USE
          Public data for enumerated Unicode general category types

static byte SPACE_SEPARATOR
          Public data for enumerated Unicode general category types

static byte START_PUNCTUATION
          Public data for enumerated Unicode general category types

static byte SURROGATE
          Public data for enumerated Unicode general category types

static byte TITLECASE_LETTER
          Public data for enumerated Unicode general category types

static Class TYPE
          The Class object representing the primitive type char.

static byte UNASSIGNED
          Public data for enumerated Unicode general category types

static byte UPPERCASE_LETTER
          Public data for enumerated Unicode general category types

Constructor Summary

Character(char value)
          Constructs a Character object and initializes it so that it represents the primitive value argument.

Method Summary

char charValue()
          Returns the value of this Character object.

int compareTo(Character anotherCharacter)
          Compares two Characters numerically.

int compareTo(Object o)
          Compares this Character to another Object.

static int digit(char ch, int radix)
          Returns the numeric value of the character ch in the specified radix.

boolean equals(Object obj)
          Compares this object against the specified object.

static char forDigit(int digit, int radix)
          Determines the character representation for a specific digit in the specified radix.

static int getNumericValue(char ch)
          Returns the Unicode numeric value of the character as a nonnegative integer.

static int getType(char ch)
          Returns a value indicating a character category.

int hashCode()
          Returns a hash code for this Character.

static boolean isDefined(char ch)
          Determines if a character has a defined meaning in Unicode.

static boolean isDigit(char ch)
          Determines if the specified character is a digit.

static boolean isIdentifierIgnorable(char ch)
          Determines if the specified character should be regarded as an ignorable character in a Java identifier or a Unicode identifier.

static boolean isISOControl(char ch)
          Determines if the specified character is an ISO control character.

static boolean isJavaIdentifierPart(char ch)
          Determines if the specified character may be part of a Java identifier as other than the first character.

static boolean isJavaIdentifierStart(char ch)
          Determines if the specified character is permissible as the first character in a Java identifier.

static boolean isJavaLetter(char ch)
          Deprecated. Replaced by isJavaIdentifierStart(char).

static boolean isJavaLetterOrDigit(char ch)
          Deprecated. Replaced by isJavaIdentifierPart(char).

static boolean isLetter(char ch)
          Determines if the specified character is a letter.

static boolean isLetterOrDigit(char ch)
          Determines if the specified character is a letter or digit.

static boolean isLowerCase(char ch)
          Determines if the specified character is a lowercase character.

static boolean isSpace(char ch)
          Deprecated. Replaced by isWhitespace(char).

static boolean isSpaceChar(char ch)
          Determines if the specified character is a Unicode space character.

static boolean isTitleCase(char ch)
          Determines if the specified character is a titlecase character.

static boolean isUnicodeIdentifierPart(char ch)
          Determines if the specified character may be part of a Unicode identifier as other than the first character.

static boolean isUnicodeIdentifierStart(char ch)
          Determines if the specified character is permissible as the first character in a Unicode identifier.

static boolean isUpperCase(char ch)
          Determines if the specified character is an uppercase character.

static boolean isWhitespace(char ch)
          Determines if the specified character is white space according to Java.

static char toLowerCase(char ch)
          The given character is mapped to its lowercase equivalent; if the character has no lowercase equivalent, the character itself is returned.

String toString()
          Returns a String object representing this character's value.

static char toTitleCase(char ch)
          Converts the character argument to titlecase.

static char toUpperCase(char ch)
          Converts the character argument to uppercase.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

MIN_RADIX

public static final int MIN_RADIX

The minimum radix available for conversion to and from Strings. The constant value of this field is the smallest value permitted for the radix argument in radix-conversion methods such as the digit method, the forDigit method, and the toString method of class Integer.

See Also:: digit(char, int), forDigit(int, int), Integer.toString(int, int), Integer.valueOf(java.lang.String)

MAX_RADIX

public static final int MAX_RADIX

The maximum radix available for conversion to and from Strings. The constant value of this field is the largest value permitted for the radix argument in radix-conversion methods such as the digit method, the forDigit method, and the toString method of class Integer.

See Also:: digit(char, int), forDigit(int, int), Integer.toString(int, int), Integer.valueOf(java.lang.String)

MIN_VALUE

public static final char MIN_VALUE

The constant value of this field is the smallest value of type char.

Since:: JDK1.0.2

MAX_VALUE

public static final char MAX_VALUE

The constant value of this field is the largest value of type char.

Since:: JDK1.0.2

TYPE

public static final Class TYPE

The Class object representing the primitive type char.

Since:: JDK1.1