Byte (Java 2 Platform SE 5.0) (original) (raw)

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 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 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, -27.

See Also:

Constant Field Values

MAX_VALUE

public static final byte MAX_VALUE

A constant holding the maximum value a byte can have, 27-1.

See Also:

Constant Field Values

TYPE

public static final Class<Byte> TYPE

The Class instance representing the primitive typebyte.

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 theString parameter. The string is converted to abyte value in exactly the manner used by theparseByte method for radix 10.

Parameters:

s - the String to be converted to a Byte

Throws:

[NumberFormatException](../../java/lang/NumberFormatException.html "class in java.lang") - If the String does not contain a parsable byte.

See Also:

[parseByte(java.lang.String, int)](../../java/lang/Byte.html#parseByte%28java.lang.String, int%29)

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 specifiedbyte value. If a new Byte 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 by caching 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 decimalbyte. 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)](../../java/lang/Byte.html#parseByte%28java.lang.String, int%29) method.

Parameters:

s - a String containing the byte representation to be parsed

Returns:

the byte value represented by the argument in decimal

Throws:

[NumberFormatException](../../java/lang/NumberFormatException.html "class in java.lang") - if 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)](../../java/lang/Character.html#digit%28char, int%29) 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 typebyte.

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](../../java/lang/NumberFormatException.html "class in java.lang") - 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)](../../java/lang/Byte.html#parseByte%28java.lang.String, int%29) 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](../../java/lang/NumberFormatException.html "class in java.lang") - 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 aByte 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](../../java/lang/NumberFormatException.html "class in java.lang") - 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:

Signopt DecimalNumeral

Signopt 0x HexDigits

Signopt 0X HexDigits

Signopt # HexDigits

Signopt 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 theString.

Parameters:

nm - the String to decode.

Returns:

a Byte object holding the byte value represented by nm

Throws:

[NumberFormatException](../../java/lang/NumberFormatException.html "class in java.lang") - if the String does not contain a parsable byte.

See Also:

[parseByte(java.lang.String, int)](../../java/lang/Byte.html#parseByte%28java.lang.String, int%29)

byteValue

public byte byteValue()

Returns the value of this Byte as abyte.

Overrides:

[byteValue](../../java/lang/Number.html#byteValue%28%29) in class [Number](../../java/lang/Number.html "class in java.lang")

Returns:

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

shortValue

public short shortValue()

Returns the value of this Byte as ashort.

Overrides:

[shortValue](../../java/lang/Number.html#shortValue%28%29) in class [Number](../../java/lang/Number.html "class in java.lang")

Returns:

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

intValue

public int intValue()

Returns the value of this Byte as anint.

Specified by:

[intValue](../../java/lang/Number.html#intValue%28%29) in class [Number](../../java/lang/Number.html "class in java.lang")

Returns:

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

longValue

public long longValue()

Returns the value of this Byte as along.

Specified by:

[longValue](../../java/lang/Number.html#longValue%28%29) in class [Number](../../java/lang/Number.html "class in java.lang")

Returns:

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

floatValue

public float floatValue()

Returns the value of this Byte as afloat.

Specified by:

[floatValue](../../java/lang/Number.html#floatValue%28%29) in class [Number](../../java/lang/Number.html "class in java.lang")

Returns:

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

doubleValue

public double doubleValue()

Returns the value of this Byte as adouble.

Specified by:

[doubleValue](../../java/lang/Number.html#doubleValue%28%29) in class [Number](../../java/lang/Number.html "class in java.lang")

Returns:

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

toString

public String toString()

Returns a String object representing thisByte'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 thetoString(byte) method.

Overrides:

[toString](../../java/lang/Object.html#toString%28%29) in class [Object](../../java/lang/Object.html "class in java.lang")

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](../../java/lang/Object.html#hashCode%28%29) in class [Object](../../java/lang/Object.html "class in java.lang")

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 istrue if and only if the argument is notnull and is a Byte object that contains the same byte value as this object.

Overrides:

[equals](../../java/lang/Object.html#equals%28java.lang.Object%29) in class [Object](../../java/lang/Object.html "class in java.lang")

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](../../java/lang/Comparable.html#compareTo%28T%29) in interface [Comparable](../../java/lang/Comparable.html "interface in java.lang")<[Byte](../../java/lang/Byte.html "class in java.lang")>

Parameters:

anotherByte - the Byte to be compared.

Returns:

the value 0 if this Byte is equal to the argument Byte; a value less than0 if this Byte is numerically less than the argument Byte; and a value greater than0 if this Byte is numerically greater than the argument Byte (signed comparison).

Since:

1.2

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For further API reference and developer documentation, see Java 2 SDK SE Developer Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.

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