java.lang
Class Byte

java.lang.Object
  java.lang.Number
      java.lang.Byte

All Implemented Interfaces:

Serializable , Comparable < Byte >

public final class Byte
extends Number
implements Comparable<Byte>

The Byte class wraps a value of primitive type byte in an object. An object of type Byte contains a single field whose type is byte.

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

Since:

JDK1.1

See Also:

Number , Serialized Form

MIN_VALUE

public static final byte MIN_VALUE

A constant holding the minimum value a byte can have, -2 ⁷ .

See Also:

Constant Field Values

MAX_VALUE

public static final byte MAX_VALUE

A constant holding the maximum value a byte can have, 2 ⁷ -1.

See Also:

Constant Field Values

TYPE

public static final Class<Byte> TYPE

The Class instance representing the primitive type byte.

SIZE

public static final int SIZE

The number of bits used to represent a byte value in two's complement binary form.

Since:

1.5

See Also:

Constant Field Values

Byte

public Byte(byte value)

Constructs a newly allocated Byte object that represents the specified byte value.

Parameters:

value - the value to be represented by the Byte.

Byte

public Byte(String s)
     throws NumberFormatException

Constructs a newly allocated Byte object that represents the byte value indicated by the String parameter. The string is converted to a byte value in exactly the manner used by the parseByte method for radix 10.

Parameters:

s - the String to be converted to a Byte

Throws:

NumberFormatException - If the String does not contain a parsable byte.

See Also:

parseByte(java.lang.String, int)

toString

public static String toString(byte b)

Returns a new String object representing the specified byte. The radix is assumed to be 10.

Parameters:

b - the byte to be converted

Returns:

the string representation of the specified byte

See Also:

Integer.toString(int)

valueOf

public static Byte valueOf(byte b)

Returns a Byte instance representing the specified byte value. If a new Byte instance is not required, this method should generally be used in preference to the constructor Byte(byte) , as this method is likely to to yield significantly better space and time performance by caching cacheing frequently requested values.

Parameters:

b - a byte value.

Returns:

a Byte instance representing b .

Since:

1.5

parseByte

public static byte parseByte(String s)
                      throws NumberFormatException

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. The resulting byte value is returned, exactly as if the argument and the radix 10 were given as arguments to the parseByte(java.lang.String, int) method.

Parameters:

s - a String containing the byte representation to be parsed

Returns:

the byte value represented by the argument in decimal

Throws:

NumberFormatException - if the the string does not contain a parsable byte.

parseByte

public static byte parseByte(String s,
                             int radix)
                      throws NumberFormatException

Parses the string argument as a signed byte in the radix specified by the second argument. The characters in the string must all be digits, of the specified radix (as determined by whether Character.digit(char, int) returns a nonnegative value) except that the first character may be an ASCII minus sign '-' ('\u002D') to indicate a negative value. The resulting byte value is returned.

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

• The first argument is null or is a string of length zero.
• The radix is either smaller than Character.MIN_RADIX or larger than Character.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') provided that the string is longer than length 1.
• The value represented by the string is not a value of type byte.

Parameters:

s - the String containing the byte representation to be parsed

radix - the radix to be used while parsing s

Returns:

the byte value represented by the string argument in the specified radix

Throws:

NumberFormatException - If the string does not contain a parsable byte.

valueOf

public static Byte valueOf(String s,
                           int radix)
                    throws NumberFormatException

Returns a Byte object holding the value extracted from the specified String when parsed with the radix given by the second argument. The first argument is interpreted as representing a signed byte in the radix specified by the second argument, exactly as if the argument were given to the parseByte(java.lang.String, int) method. The result is a Byte object that represents the byte value specified by the string.

In other words, this method returns a Byte 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 interpreting s

Returns:

a Byte object holding the value represented by the string argument in the specified radix.

Throws:

NumberFormatException - If the String does not contain a parsable byte.

valueOf

public static Byte valueOf(String s)
                    throws NumberFormatException

Returns a Byte object holding the value given by the specified String. The argument is interpreted as representing a signed decimal byte, exactly as if the argument were given to the parseByte(java.lang.String) method. The result is a Byte object that represents the byte value specified by the string.

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

new Byte(Byte.parseByte(s))

Parameters:

s - the string to be parsed

Returns:

a Byte object holding the value represented by the string argument

Throws:

NumberFormatException - If the String does not contain a parsable byte.

decode

public static Byte decode(String nm)
                   throws NumberFormatException

Decodes a String into a Byte. Accepts decimal, hexadecimal, and octal numbers given by the following grammar:

DecodableString:

Sign _opt DecimalNumeral

Sign _opt 0x HexDigits

Sign _opt 0X HexDigits

Sign _opt # HexDigits

Sign _opt 0 OctalDigits

Sign:

-

DecimalNumeral , HexDigits , and OctalDigits are defined in §3.10.1 of the Java Language Specification .

The sequence of characters following an (optional) negative 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 a NumberFormatException will be thrown. The result is negated if first character of the specified String is the minus sign. No whitespace characters are permitted in the String.

Parameters:

nm - the String to decode.

Returns:

a Byte object holding the byte value represented by nm

Throws:

NumberFormatException - if the String does not contain a parsable byte.

See Also:

parseByte(java.lang.String, int)

byteValue

public byte byteValue()

Returns the value of this Byte as a byte.

Overrides:

byteValue in class Number

Returns:

the numeric value represented by this object after conversion to type byte.

shortValue

public short shortValue()

Returns the value of this Byte as a short.

Overrides:

shortValue in class Number

Returns:

the numeric value represented by this object after conversion to type short.

intValue

public int intValue()

Returns the value of this Byte as an int.

Specified by:

intValue in class Number

Returns:

the numeric value represented by this object after conversion to type int.

longValue

public long longValue()

Returns the value of this Byte as a long.

Specified by:

longValue in class Number

Returns:

the numeric value represented by this object after conversion to type long.

floatValue

public float floatValue()

Returns the value of this Byte as a float.

Specified by:

floatValue in class Number

Returns:

the numeric value represented by this object after conversion to type float.

doubleValue

public double doubleValue()

Returns the value of this Byte as a double.

Specified by:

doubleValue in class Number

Returns:

the numeric value represented by this object after conversion to type double.

toString

public String toString()

Returns a String object representing this Byte's value. The value is converted to signed decimal representation and returned as a string, exactly as if the byte value were given as an argument to the toString(byte) method.

Overrides:

toString in class Object

Returns:

a string representation of the value of this object in base 10.

hashCode

public int hashCode()

Returns a hash code for this Byte.

Overrides:

hashCode in class Object

Returns:

a hash code value for this object.

See Also:

Object.equals(java.lang.Object) , Hashtable

equals

public boolean equals(Object obj)

Compares this object to the specified object. The result is true if and only if the argument is not null and is a Byte object that contains the same byte 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() , Hashtable

compareTo

public int compareTo(Byte anotherByte)

Compares two Byte objects numerically.

Specified by:

compareTo in interface Comparable < Byte >

Parameters:

anotherByte - the Byte to be compared.

Returns:

the value 0 if this Byte is equal to the argument Byte; a value less than 0 if this Byte is numerically less than the argument Byte; and a value greater than 0 if this Byte is numerically greater than the argument Byte (signed comparison).

Since:

1.2