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package java.lang;

import jdk.internal.HotSpotIntrinsicCandidate;

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.

Author: Nakul Saraiya, Joseph D. Darcy
See Also:
Since: 1.1
/** * * The {@code Byte} class wraps a value of primitive type {@code byte} * in an object. An object of type {@code Byte} contains a single * field whose type is {@code byte}. * * <p>In addition, this class provides several methods for converting * a {@code byte} to a {@code String} and a {@code String} to a {@code * byte}, as well as other constants and methods useful when dealing * with a {@code byte}. * * @author Nakul Saraiya * @author Joseph D. Darcy * @see java.lang.Number * @since 1.1 */
public final class Byte extends Number implements Comparable<Byte> {
A constant holding the minimum value a byte can have, -27.
/** * A constant holding the minimum value a {@code byte} can * have, -2<sup>7</sup>. */
public static final byte MIN_VALUE = -128;
A constant holding the maximum value a byte can have, 27-1.
/** * A constant holding the maximum value a {@code byte} can * have, 2<sup>7</sup>-1. */
public static final byte MAX_VALUE = 127;
The Class instance representing the primitive type byte.
/** * The {@code Class} instance representing the primitive type * {@code byte}. */
@SuppressWarnings("unchecked") public static final Class<Byte> TYPE = (Class<Byte>) Class.getPrimitiveClass("byte");
Returns a new String object representing the specified byte. The radix is assumed to be 10.
Params:
  • b – the byte to be converted
See Also:
Returns:the string representation of the specified byte
/** * Returns a new {@code String} object representing the * specified {@code byte}. The radix is assumed to be 10. * * @param b the {@code byte} to be converted * @return the string representation of the specified {@code byte} * @see java.lang.Integer#toString(int) */
public static String toString(byte b) { return Integer.toString((int)b, 10); } private static class ByteCache { private ByteCache(){} static final Byte cache[] = new Byte[-(-128) + 127 + 1]; static { for(int i = 0; i < cache.length; i++) cache[i] = new Byte((byte)(i - 128)); } }
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 yield significantly better space and time performance since all byte values are cached.
Params:
  • b – a byte value.
Returns:a Byte instance representing b.
Since: 1.5
/** * Returns a {@code Byte} instance representing the specified * {@code byte} value. * If a new {@code Byte} instance is not required, this method * should generally be used in preference to the constructor * {@link #Byte(byte)}, as this method is likely to yield * significantly better space and time performance since * all byte values are cached. * * @param b a byte value. * @return a {@code Byte} instance representing {@code b}. * @since 1.5 */
@HotSpotIntrinsicCandidate public static Byte valueOf(byte b) { final int offset = 128; return ByteCache.cache[(int)b + offset]; }
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 '-' ('\u005Cu002D') to indicate a negative value or an ASCII plus sign '+' ('\u005Cu002B') to indicate a positive 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 '-' ('\u005Cu002D') or plus sign '+' ('\u005Cu002B') provided that the string is longer than length 1.
  • The value represented by the string is not a value of type byte.
Params:
  • s – the String containing the byte representation to be parsed
  • radix – the radix to be used while parsing s
Throws:
Returns: the byte value represented by the string argument in the specified radix
/** * Parses the string argument as a signed {@code 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 {@link java.lang.Character#digit(char, * int)} returns a nonnegative value) except that the first * character may be an ASCII minus sign {@code '-'} * ({@code '\u005Cu002D'}) to indicate a negative value or an * ASCII plus sign {@code '+'} ({@code '\u005Cu002B'}) to * indicate a positive value. The resulting {@code byte} value is * returned. * * <p>An exception of type {@code NumberFormatException} is * thrown if any of the following situations occurs: * <ul> * <li> The first argument is {@code null} or is a string of * length zero. * * <li> The radix is either smaller than {@link * java.lang.Character#MIN_RADIX} or larger than {@link * java.lang.Character#MAX_RADIX}. * * <li> Any character of the string is not a digit of the * specified radix, except that the first character may be a minus * sign {@code '-'} ({@code '\u005Cu002D'}) or plus sign * {@code '+'} ({@code '\u005Cu002B'}) provided that the * string is longer than length 1. * * <li> The value represented by the string is not a value of type * {@code byte}. * </ul> * * @param s the {@code String} containing the * {@code byte} * representation to be parsed * @param radix the radix to be used while parsing {@code s} * @return the {@code byte} value represented by the string * argument in the specified radix * @throws NumberFormatException If the string does * not contain a parsable {@code byte}. */
public static byte parseByte(String s, int radix) throws NumberFormatException { int i = Integer.parseInt(s, radix); if (i < MIN_VALUE || i > MAX_VALUE) throw new NumberFormatException( "Value out of range. Value:\"" + s + "\" Radix:" + radix); return (byte)i; }
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 '-' ('\u005Cu002D') to indicate a negative value or an ASCII plus sign '+' ('\u005Cu002B') to indicate a positive value. The resulting byte value is returned, exactly as if the argument and the radix 10 were given as arguments to the parseByte(String, int) method.
Params:
  • s – a String containing the byte representation to be parsed
Throws:
Returns: the byte value represented by the argument in decimal
/** * Parses the string argument as a signed decimal {@code * byte}. The characters in the string must all be decimal digits, * except that the first character may be an ASCII minus sign * {@code '-'} ({@code '\u005Cu002D'}) to indicate a negative * value or an ASCII plus sign {@code '+'} * ({@code '\u005Cu002B'}) to indicate a positive value. The * resulting {@code byte} value is returned, exactly as if the * argument and the radix 10 were given as arguments to the {@link * #parseByte(java.lang.String, int)} method. * * @param s a {@code String} containing the * {@code byte} representation to be parsed * @return the {@code byte} value represented by the * argument in decimal * @throws NumberFormatException if the string does not * contain a parsable {@code byte}. */
public static byte parseByte(String s) throws NumberFormatException { return parseByte(s, 10); }
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(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))
Params:
  • s – the string to be parsed
  • radix – the radix to be used in interpreting s
Throws:
Returns: a Byte object holding the value represented by the string argument in the specified radix.
/** * Returns a {@code Byte} object holding the value * extracted from the specified {@code String} when parsed * with the radix given by the second argument. The first argument * is interpreted as representing a signed {@code byte} in * the radix specified by the second argument, exactly as if the * argument were given to the {@link #parseByte(java.lang.String, * int)} method. The result is a {@code Byte} object that * represents the {@code byte} value specified by the string. * * <p> In other words, this method returns a {@code Byte} object * equal to the value of: * * <blockquote> * {@code new Byte(Byte.parseByte(s, radix))} * </blockquote> * * @param s the string to be parsed * @param radix the radix to be used in interpreting {@code s} * @return a {@code Byte} object holding the value * represented by the string argument in the * specified radix. * @throws NumberFormatException If the {@code String} does * not contain a parsable {@code byte}. */
public static Byte valueOf(String s, int radix) throws NumberFormatException { return valueOf(parseByte(s, radix)); }
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(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))
Params:
  • s – the string to be parsed
Throws:
Returns: a Byte object holding the value represented by the string argument
/** * Returns a {@code Byte} object holding the value * given by the specified {@code String}. The argument is * interpreted as representing a signed decimal {@code byte}, * exactly as if the argument were given to the {@link * #parseByte(java.lang.String)} method. The result is a * {@code Byte} object that represents the {@code byte} * value specified by the string. * * <p> In other words, this method returns a {@code Byte} object * equal to the value of: * * <blockquote> * {@code new Byte(Byte.parseByte(s))} * </blockquote> * * @param s the string to be parsed * @return a {@code Byte} object holding the value * represented by the string argument * @throws NumberFormatException If the {@code String} does * not contain a parsable {@code byte}. */
public static Byte valueOf(String s) throws NumberFormatException { return valueOf(s, 10); }
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 as defined in section 3.10.1 of The 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 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.

Params:
  • nm – the String to decode.
Throws:
See Also:
Returns: a Byte object holding the byte value represented by nm
/** * Decodes a {@code String} into a {@code Byte}. * Accepts decimal, hexadecimal, and octal numbers given by * the following grammar: * * <blockquote> * <dl> * <dt><i>DecodableString:</i> * <dd><i>Sign<sub>opt</sub> DecimalNumeral</i> * <dd><i>Sign<sub>opt</sub></i> {@code 0x} <i>HexDigits</i> * <dd><i>Sign<sub>opt</sub></i> {@code 0X} <i>HexDigits</i> * <dd><i>Sign<sub>opt</sub></i> {@code #} <i>HexDigits</i> * <dd><i>Sign<sub>opt</sub></i> {@code 0} <i>OctalDigits</i> * * <dt><i>Sign:</i> * <dd>{@code -} * <dd>{@code +} * </dl> * </blockquote> * * <i>DecimalNumeral</i>, <i>HexDigits</i>, and <i>OctalDigits</i> * are as defined in section 3.10.1 of * <cite>The Java&trade; Language Specification</cite>, * except that underscores are not accepted between digits. * * <p>The sequence of characters following an optional * sign and/or radix specifier ("{@code 0x}", "{@code 0X}", * "{@code #}", or leading zero) is parsed as by the {@code * Byte.parseByte} method with the indicated radix (10, 16, or 8). * This sequence of characters must represent a positive value or * a {@link NumberFormatException} will be thrown. The result is * negated if first character of the specified {@code String} is * the minus sign. No whitespace characters are permitted in the * {@code String}. * * @param nm the {@code String} to decode. * @return a {@code Byte} object holding the {@code byte} * value represented by {@code nm} * @throws NumberFormatException if the {@code String} does not * contain a parsable {@code byte}. * @see java.lang.Byte#parseByte(java.lang.String, int) */
public static Byte decode(String nm) throws NumberFormatException { int i = Integer.decode(nm); if (i < MIN_VALUE || i > MAX_VALUE) throw new NumberFormatException( "Value " + i + " out of range from input " + nm); return valueOf((byte)i); }
The value of the Byte.
@serial
/** * The value of the {@code Byte}. * * @serial */
private final byte value;
Constructs a newly allocated Byte object that represents the specified byte value.
Params:
  • value – the value to be represented by the Byte.
Deprecated: It is rarely appropriate to use this constructor. The static factory valueOf(byte) is generally a better choice, as it is likely to yield significantly better space and time performance.
/** * Constructs a newly allocated {@code Byte} object that * represents the specified {@code byte} value. * * @param value the value to be represented by the * {@code Byte}. * * @deprecated * It is rarely appropriate to use this constructor. The static factory * {@link #valueOf(byte)} is generally a better choice, as it is * likely to yield significantly better space and time performance. */
@Deprecated(since="9") public Byte(byte value) { this.value = value; }
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.
Params:
  • s – the String to be converted to a Byte
Throws:
Deprecated: It is rarely appropriate to use this constructor. Use parseByte(String) to convert a string to a byte primitive, or use valueOf(String) to convert a string to a Byte object.
/** * Constructs a newly allocated {@code Byte} object that * represents the {@code byte} value indicated by the * {@code String} parameter. The string is converted to a * {@code byte} value in exactly the manner used by the * {@code parseByte} method for radix 10. * * @param s the {@code String} to be converted to a * {@code Byte} * @throws NumberFormatException if the {@code String} * does not contain a parsable {@code byte}. * * @deprecated * It is rarely appropriate to use this constructor. * Use {@link #parseByte(String)} to convert a string to a * {@code byte} primitive, or use {@link #valueOf(String)} * to convert a string to a {@code Byte} object. */
@Deprecated(since="9") public Byte(String s) throws NumberFormatException { this.value = parseByte(s, 10); }
Returns the value of this Byte as a byte.
/** * Returns the value of this {@code Byte} as a * {@code byte}. */
@HotSpotIntrinsicCandidate public byte byteValue() { return value; }
Returns the value of this Byte as a short after a widening primitive conversion.
@jls5.1.2 Widening Primitive Conversions
/** * Returns the value of this {@code Byte} as a {@code short} after * a widening primitive conversion. * @jls 5.1.2 Widening Primitive Conversions */
public short shortValue() { return (short)value; }
Returns the value of this Byte as an int after a widening primitive conversion.
@jls5.1.2 Widening Primitive Conversions
/** * Returns the value of this {@code Byte} as an {@code int} after * a widening primitive conversion. * @jls 5.1.2 Widening Primitive Conversions */
public int intValue() { return (int)value; }
Returns the value of this Byte as a long after a widening primitive conversion.
@jls5.1.2 Widening Primitive Conversions
/** * Returns the value of this {@code Byte} as a {@code long} after * a widening primitive conversion. * @jls 5.1.2 Widening Primitive Conversions */
public long longValue() { return (long)value; }
Returns the value of this Byte as a float after a widening primitive conversion.
@jls5.1.2 Widening Primitive Conversions
/** * Returns the value of this {@code Byte} as a {@code float} after * a widening primitive conversion. * @jls 5.1.2 Widening Primitive Conversions */
public float floatValue() { return (float)value; }
Returns the value of this Byte as a double after a widening primitive conversion.
@jls5.1.2 Widening Primitive Conversions
/** * Returns the value of this {@code Byte} as a {@code double} * after a widening primitive conversion. * @jls 5.1.2 Widening Primitive Conversions */
public double doubleValue() { return (double)value; }
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.
Returns: a string representation of the value of this object in base 10.
/** * Returns a {@code String} object representing this * {@code Byte}'s value. The value is converted to signed * decimal representation and returned as a string, exactly as if * the {@code byte} value were given as an argument to the * {@link java.lang.Byte#toString(byte)} method. * * @return a string representation of the value of this object in * base&nbsp;10. */
public String toString() { return Integer.toString((int)value); }
Returns a hash code for this Byte; equal to the result of invoking intValue().
Returns:a hash code value for this Byte
/** * Returns a hash code for this {@code Byte}; equal to the result * of invoking {@code intValue()}. * * @return a hash code value for this {@code Byte} */
@Override public int hashCode() { return Byte.hashCode(value); }
Returns a hash code for a byte value; compatible with Byte.hashCode().
Params:
  • value – the value to hash
Returns:a hash code value for a byte value.
Since:1.8
/** * Returns a hash code for a {@code byte} value; compatible with * {@code Byte.hashCode()}. * * @param value the value to hash * @return a hash code value for a {@code byte} value. * @since 1.8 */
public static int hashCode(byte value) { return (int)value; }
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.
Params:
  • obj – the object to compare with
Returns: true if the objects are the same; false otherwise.
/** * Compares this object to the specified object. The result is * {@code true} if and only if the argument is not * {@code null} and is a {@code Byte} object that * contains the same {@code byte} value as this object. * * @param obj the object to compare with * @return {@code true} if the objects are the same; * {@code false} otherwise. */
public boolean equals(Object obj) { if (obj instanceof Byte) { return value == ((Byte)obj).byteValue(); } return false; }
Compares two Byte objects numerically.
Params:
  • 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
/** * Compares two {@code Byte} objects numerically. * * @param anotherByte the {@code Byte} to be compared. * @return the value {@code 0} if this {@code Byte} is * equal to the argument {@code Byte}; a value less than * {@code 0} if this {@code Byte} is numerically less * than the argument {@code Byte}; and a value greater than * {@code 0} if this {@code Byte} is numerically * greater than the argument {@code Byte} (signed * comparison). * @since 1.2 */
public int compareTo(Byte anotherByte) { return compare(this.value, anotherByte.value); }
Compares two byte values numerically. The value returned is identical to what would be returned by:
   Byte.valueOf(x).compareTo(Byte.valueOf(y))
Params:
  • x – the first byte to compare
  • y – the second byte to compare
Returns:the value 0 if x == y; a value less than 0 if x < y; and a value greater than 0 if x > y
Since:1.7
/** * Compares two {@code byte} values numerically. * The value returned is identical to what would be returned by: * <pre> * Byte.valueOf(x).compareTo(Byte.valueOf(y)) * </pre> * * @param x the first {@code byte} to compare * @param y the second {@code byte} to compare * @return the value {@code 0} if {@code x == y}; * a value less than {@code 0} if {@code x < y}; and * a value greater than {@code 0} if {@code x > y} * @since 1.7 */
public static int compare(byte x, byte y) { return x - y; }
Compares two byte values numerically treating the values as unsigned.
Params:
  • x – the first byte to compare
  • y – the second byte to compare
Returns:the value 0 if x == y; a value less than 0 if x < y as unsigned values; and a value greater than 0 if x > y as unsigned values
Since:9
/** * Compares two {@code byte} values numerically treating the values * as unsigned. * * @param x the first {@code byte} to compare * @param y the second {@code byte} to compare * @return the value {@code 0} if {@code x == y}; a value less * than {@code 0} if {@code x < y} as unsigned values; and * a value greater than {@code 0} if {@code x > y} as * unsigned values * @since 9 */
public static int compareUnsigned(byte x, byte y) { return Byte.toUnsignedInt(x) - Byte.toUnsignedInt(y); }
Converts the argument to an int by an unsigned conversion. In an unsigned conversion to an int, the high-order 24 bits of the int are zero and the low-order 8 bits are equal to the bits of the byte argument. Consequently, zero and positive byte values are mapped to a numerically equal int value and negative byte values are mapped to an int value equal to the input plus 28.
Params:
  • x – the value to convert to an unsigned int
Returns:the argument converted to int by an unsigned conversion
Since:1.8
/** * Converts the argument to an {@code int} by an unsigned * conversion. In an unsigned conversion to an {@code int}, the * high-order 24 bits of the {@code int} are zero and the * low-order 8 bits are equal to the bits of the {@code byte} argument. * * Consequently, zero and positive {@code byte} values are mapped * to a numerically equal {@code int} value and negative {@code * byte} values are mapped to an {@code int} value equal to the * input plus 2<sup>8</sup>. * * @param x the value to convert to an unsigned {@code int} * @return the argument converted to {@code int} by an unsigned * conversion * @since 1.8 */
public static int toUnsignedInt(byte x) { return ((int) x) & 0xff; }
Converts the argument to a long by an unsigned conversion. In an unsigned conversion to a long, the high-order 56 bits of the long are zero and the low-order 8 bits are equal to the bits of the byte argument. Consequently, zero and positive byte values are mapped to a numerically equal long value and negative byte values are mapped to a long value equal to the input plus 28.
Params:
  • x – the value to convert to an unsigned long
Returns:the argument converted to long by an unsigned conversion
Since:1.8
/** * Converts the argument to a {@code long} by an unsigned * conversion. In an unsigned conversion to a {@code long}, the * high-order 56 bits of the {@code long} are zero and the * low-order 8 bits are equal to the bits of the {@code byte} argument. * * Consequently, zero and positive {@code byte} values are mapped * to a numerically equal {@code long} value and negative {@code * byte} values are mapped to a {@code long} value equal to the * input plus 2<sup>8</sup>. * * @param x the value to convert to an unsigned {@code long} * @return the argument converted to {@code long} by an unsigned * conversion * @since 1.8 */
public static long toUnsignedLong(byte x) { return ((long) x) & 0xffL; }
The number of bits used to represent a byte value in two's complement binary form.
Since:1.5
/** * The number of bits used to represent a {@code byte} value in two's * complement binary form. * * @since 1.5 */
public static final int SIZE = 8;
The number of bytes used to represent a byte value in two's complement binary form.
Since:1.8
/** * The number of bytes used to represent a {@code byte} value in two's * complement binary form. * * @since 1.8 */
public static final int BYTES = SIZE / Byte.SIZE;
use serialVersionUID from JDK 1.1. for interoperability
/** use serialVersionUID from JDK 1.1. for interoperability */
private static final long serialVersionUID = -7183698231559129828L; }