Module java.base
Package java.lang

Class Byte

  • All Implemented Interfaces:
    Serializable,Comparable<Byte>
    public final classByteextendsNumberimplementsComparable<Byte>
    TheByte class wraps a value of primitive typebyte in an object. An object of typeByte contains a single field whose type isbyte.

    In addition, this class provides several methods for converting abyte to aString and aString to a byte, as well as other constants and methods useful when dealing with abyte.

    Since:
    1.1
    See Also:
    Number,Serialized Form

    • Field Summary

      Fields 
      Modifier and TypeFieldDescription
      static intBYTES
      The number of bytes used to represent abyte value in two's complement binary form.
      static byteMAX_VALUE
      A constant holding the maximum value abyte can have, 27-1.
      static byteMIN_VALUE
      A constant holding the minimum value abyte can have, -27.
      static intSIZE
      The number of bits used to represent abyte value in two's complement binary form.
      staticClass<Byte>TYPE
      TheClass instance representing the primitive typebyte.

    • Constructor Summary

      Constructors 
      ConstructorDescription
      Byte​(byte value)
      Deprecated.
      It is rarely appropriate to use this constructor.
      Byte​(String s)
      Deprecated.
      It is rarely appropriate to use this constructor.

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and TypeMethodDescription
      bytebyteValue()
      Returns the value of thisByte as abyte.
      static intcompare​(byte x, byte y)
      Compares twobyte values numerically.
      intcompareTo​(Byte anotherByte)
      Compares twoByte objects numerically.
      static intcompareUnsigned​(byte x, byte y)
      Compares twobyte values numerically treating the values as unsigned.
      staticBytedecode​(String nm)
      Decodes aString into aByte.
      doubledoubleValue()
      Returns the value of thisByte as adouble after a widening primitive conversion.
      booleanequals​(Object obj)
      Compares this object to the specified object.
      floatfloatValue()
      Returns the value of thisByte as afloat after a widening primitive conversion.
      inthashCode()
      Returns a hash code for thisByte; equal to the result of invokingintValue().
      static inthashCode​(byte value)
      Returns a hash code for abyte value; compatible withByte.hashCode().
      intintValue()
      Returns the value of thisByte as anint after a widening primitive conversion.
      longlongValue()
      Returns the value of thisByte as along after a widening primitive conversion.
      static byteparseByte​(String s)
      Parses the string argument as a signed decimal byte.
      static byteparseByte​(String s, int radix)
      Parses the string argument as a signedbyte in the radix specified by the second argument.
      shortshortValue()
      Returns the value of thisByte as ashort after a widening primitive conversion.
      StringtoString()
      Returns aString object representing thisByte's value.
      staticStringtoString​(byte b)
      Returns a newString object representing the specifiedbyte.
      static inttoUnsignedInt​(byte x)
      Converts the argument to anint by an unsigned conversion.
      static longtoUnsignedLong​(byte x)
      Converts the argument to along by an unsigned conversion.
      staticBytevalueOf​(byte b)
      Returns aByte instance representing the specifiedbyte value.
      staticBytevalueOf​(String s)
      Returns aByte object holding the value given by the specifiedString.
      staticBytevalueOf​(String s, int radix)
      Returns aByte object holding the value extracted from the specifiedString when parsed with the radix given by the second argument.

    • Field Detail

      • MIN_VALUE

        public static final byte MIN_VALUE
        A constant holding the minimum value abyte can have, -27.
        See Also:
        Constant Field Values

      • MAX_VALUE

        public static final byte MAX_VALUE
        A constant holding the maximum value abyte can have, 27-1.
        See Also:
        Constant Field Values

      • TYPE

        public static final Class<Byte> TYPE
        TheClass instance representing the primitive typebyte.

      • SIZE

        public static final int SIZE
        The number of bits used to represent abyte value in two's complement binary form.
        Since:
        1.5
        See Also:
        Constant Field Values

      • BYTES

        public static final int BYTES
        The number of bytes used to represent abyte value in two's complement binary form.
        Since:
        1.8
        See Also:
        Constant Field Values

    • Constructor Detail

      • Byte

        @Deprecated(since="9")public Byte​(byte value)
        Deprecated.
        It is rarely appropriate to use this constructor. The static factoryvalueOf(byte) is generally a better choice, as it is likely to yield significantly better space and time performance.
        Constructs a newly allocatedByte object that represents the specifiedbyte value.
        Parameters:
        value - the value to be represented by theByte.

      • Byte

        @Deprecated(since="9")public Byte​(String s)     throwsNumberFormatException
        Deprecated.
        It is rarely appropriate to use this constructor. UseparseByte(String) to convert a string to abyte primitive, or usevalueOf(String) to convert a string to aByte object.
        Constructs a newly allocatedByte object that represents thebyte value indicated by theString parameter. The string is converted to abyte value in exactly the manner used by theparseByte method for radix 10.
        Parameters:
        s - theString to be converted to aByte
        Throws:
        NumberFormatException - if theString does not contain a parsablebyte.

    • Method Detail

      • toString

        public static String toString​(byte b)
        Returns a newString object representing the specifiedbyte. The radix is assumed to be 10.
        Parameters:
        b - thebyte to be converted
        Returns:
        the string representation of the specifiedbyte
        See Also:
        Integer.toString(int)

      • valueOf

        public static Byte valueOf​(byte b)
        Returns aByte instance representing the specifiedbyte value. If a newByte instance is not required, this method should generally be used in preference to the constructorByte(byte), as this method is likely to yield significantly better space and time performance since all byte values are cached.
        Parameters:
        b - a byte value.
        Returns:
        aByte instance representingb.
        Since:
        1.5

      • parseByte

        public static byte parseByte​(String s,                             int radix)                      throwsNumberFormatException
        Parses the string argument as a signedbyte in the radix specified by the second argument. The characters in the string must all be digits, of the specified radix (as determined by whetherCharacter.digit(char, int) returns a nonnegative value) except that the first character may be an ASCII minus sign'-' ('\u002D') to indicate a negative value or an ASCII plus sign'+' ('\u002B') to indicate a positive value. The resultingbyte value is returned.

        An exception of typeNumberFormatException is thrown if any of the following situations occurs:

        • The first argument isnull or is a string of length zero.
        • The radix is either smaller thanCharacter.MIN_RADIX or larger thanCharacter.MAX_RADIX.
        • Any character of the string is not a digit of the specified radix, except that the first character may be a minus sign'-' ('\u002D') or plus sign'+' ('\u002B') provided that the string is longer than length 1.
        • The value represented by the string is not a value of typebyte.

        Parameters:
        s - theString containing thebyte representation to be parsed
        radix - the radix to be used while parsings
        Returns:
        thebyte value represented by the string argument in the specified radix
        Throws:
        NumberFormatException - If the string does not contain a parsablebyte.

      • parseByte

        public static byte parseByte​(String s)                      throwsNumberFormatException
        Parses the string argument as a signed decimal byte. The characters in the string must all be decimal digits, except that the first character may be an ASCII minus sign'-' ('\u002D') to indicate a negative value or an ASCII plus sign'+' ('\u002B') to indicate a positive value. The resultingbyte value is returned, exactly as if the argument and the radix 10 were given as arguments to theparseByte(java.lang.String, int) method.
        Parameters:
        s - aString containing thebyte representation to be parsed
        Returns:
        thebyte value represented by the argument in decimal
        Throws:
        NumberFormatException - if the string does not contain a parsablebyte.

      • valueOf

        public static Byte valueOf​(String s,                           int radix)                    throwsNumberFormatException
        Returns aByte object holding the value extracted from the specifiedString when parsed with the radix given by the second argument. The first argument is interpreted as representing a signedbyte in the radix specified by the second argument, exactly as if the argument were given to theparseByte(java.lang.String, int) method. The result is aByte object that represents thebyte value specified by the string.

        In other words, this method returns aByte object equal to the value of:

        new Byte(Byte.parseByte(s, radix))

        Parameters:
        s - the string to be parsed
        radix - the radix to be used in interpretings
        Returns:
        aByte object holding the value represented by the string argument in the specified radix.
        Throws:
        NumberFormatException - If theString does not contain a parsablebyte.

      • valueOf

        public static Byte valueOf​(String s)                    throwsNumberFormatException
        Returns aByte object holding the value given by the specifiedString. The argument is interpreted as representing a signed decimalbyte, exactly as if the argument were given to theparseByte(java.lang.String) method. The result is aByte object that represents thebyte value specified by the string.

        In other words, this method returns aByte object equal to the value of:

        new Byte(Byte.parseByte(s))

        Parameters:
        s - the string to be parsed
        Returns:
        aByte object holding the value represented by the string argument
        Throws:
        NumberFormatException - If theString does not contain a parsablebyte.

      • decode

        public static Byte decode​(String nm)                   throwsNumberFormatException
        Decodes aString into aByte. Accepts decimal, hexadecimal, and octal numbers given by the following grammar:
        DecodableString:
        Signopt DecimalNumeral
        Signopt0xHexDigits
        Signopt0XHexDigits
        Signopt#HexDigits
        Signopt0OctalDigits
        Sign:
        -
        +
        DecimalNumeral,HexDigits, andOctalDigits are as defined in section 3.10.1 ofThe Java™ Language Specification, except that underscores are not accepted between digits.

        The sequence of characters following an optional sign and/or radix specifier ("0x", "0X", "#", or leading zero) is parsed as by the Byte.parseByte method with the indicated radix (10, 16, or 8). This sequence of characters must represent a positive value or aNumberFormatException will be thrown. The result is negated if first character of the specifiedString is the minus sign. No whitespace characters are permitted in theString.

        Parameters:
        nm - theString to decode.
        Returns:
        aByte object holding thebyte value represented bynm
        Throws:
        NumberFormatException - if theString does not contain a parsablebyte.
        See Also:
        parseByte(java.lang.String, int)

      • byteValue

        public byte byteValue()
        Returns the value of thisByte as abyte.
        Overrides:
        byteValue in class Number
        Returns:
        the numeric value represented by this object after conversion to typebyte.

      • shortValue

        public short shortValue()
        Returns the value of thisByte as ashort after a widening primitive conversion.
        Overrides:
        shortValue in class Number
        Returns:
        the numeric value represented by this object after conversion to typeshort.
        SeeThe Java™ Language Specification:
        5.1.2 Widening Primitive Conversions

      • intValue

        public int intValue()
        Returns the value of thisByte as anint after a widening primitive conversion.
        Specified by:
        intValue in class Number
        Returns:
        the numeric value represented by this object after conversion to typeint.
        SeeThe Java™ Language Specification:
        5.1.2 Widening Primitive Conversions

      • longValue

        public long longValue()
        Returns the value of thisByte as along after a widening primitive conversion.
        Specified by:
        longValue in class Number
        Returns:
        the numeric value represented by this object after conversion to typelong.
        SeeThe Java™ Language Specification:
        5.1.2 Widening Primitive Conversions

      • floatValue

        public float floatValue()
        Returns the value of thisByte as afloat after a widening primitive conversion.
        Specified by:
        floatValue in class Number
        Returns:
        the numeric value represented by this object after conversion to typefloat.
        SeeThe Java™ Language Specification:
        5.1.2 Widening Primitive Conversions

      • doubleValue

        public double doubleValue()
        Returns the value of thisByte as adouble after a widening primitive conversion.
        Specified by:
        doubleValue in class Number
        Returns:
        the numeric value represented by this object after conversion to typedouble.
        SeeThe Java™ Language Specification:
        5.1.2 Widening Primitive Conversions

      • toString

        public String toString()
        Returns aString object representing thisByte's value. The value is converted to signed decimal representation and returned as a string, exactly as if thebyte value were given as an argument to thetoString(byte) method.
        Overrides:
        toString in class Object
        Returns:
        a string representation of the value of this object in base 10.

      • hashCode

        public static int hashCode​(byte value)
        Returns a hash code for abyte value; compatible withByte.hashCode().
        Parameters:
        value - the value to hash
        Returns:
        a hash code value for abyte value.
        Since:
        1.8

      • equals

        public boolean equals​(Object obj)
        Compares this object to the specified object. The result istrue if and only if the argument is notnull and is aByte object that contains the samebyte value as this object.
        Overrides:
        equals in class Object
        Parameters:
        obj - the object to compare with
        Returns:
        true if the objects are the same;false otherwise.
        See Also:
        Object.hashCode(),HashMap

      • compareTo

        public int compareTo​(Byte anotherByte)
        Compares twoByte objects numerically.
        Specified by:
        compareTo in interface Comparable<Byte>
        Parameters:
        anotherByte - theByte to be compared.
        Returns:
        the value0 if thisByte is equal to the argumentByte; a value less than0 if thisByte is numerically less than the argumentByte; and a value greater than0 if thisByte is numerically greater than the argumentByte (signed comparison).
        Since:
        1.2

      • compare

        public static int compare​(byte x,                          byte y)
        Compares twobyte values numerically. The value returned is identical to what would be returned by:
            Byte.valueOf(x).compareTo(Byte.valueOf(y))
        Parameters:
        x - the firstbyte to compare
        y - the secondbyte to compare
        Returns:
        the value0 ifx == y; a value less than0 ifx < y; and a value greater than0 ifx > y
        Since:
        1.7

      • compareUnsigned

        public static int compareUnsigned​(byte x,                                  byte y)
        Compares twobyte values numerically treating the values as unsigned.
        Parameters:
        x - the firstbyte to compare
        y - the secondbyte to compare
        Returns:
        the value0 ifx == y; a value less than0 ifx < y as unsigned values; and a value greater than0 ifx > y as unsigned values
        Since:
        9

      • toUnsignedInt

        public static int toUnsignedInt​(byte x)
        Converts the argument to anint by an unsigned conversion. In an unsigned conversion to anint, the high-order 24 bits of theint are zero and the low-order 8 bits are equal to the bits of thebyte argument. Consequently, zero and positivebyte values are mapped to a numerically equalint value and negative byte values are mapped to anint value equal to the input plus 28.
        Parameters:
        x - the value to convert to an unsignedint
        Returns:
        the argument converted toint by an unsigned conversion
        Since:
        1.8

      • toUnsignedLong

        public static long toUnsignedLong​(byte x)
        Converts the argument to along by an unsigned conversion. In an unsigned conversion to along, the high-order 56 bits of thelong are zero and the low-order 8 bits are equal to the bits of thebyte argument. Consequently, zero and positivebyte values are mapped to a numerically equallong value and negative byte values are mapped to along value equal to the input plus 28.
        Parameters:
        x - the value to convert to an unsignedlong
        Returns:
        the argument converted tolong by an unsigned conversion
        Since:
        1.8