| /* | |
| * Copyright (c) 1996, 2025, Oracle and/or its affiliates. All rights reserved. | |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
| * | |
| * This code is free software; you can redistribute it and/or modify it | |
| * under the terms of the GNU General Public License version 2 only, as | |
| * published by the Free Software Foundation. Oracle designates this | |
| * particular file as subject to the "Classpath" exception as provided | |
| * by Oracle in the LICENSE file that accompanied this code. | |
| * | |
| * This code is distributed in the hope that it will be useful, but WITHOUT | |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License | |
| * version 2 for more details (a copy is included in the LICENSE file that | |
| * accompanied this code). | |
| * | |
| * You should have received a copy of the GNU General Public License version | |
| * 2 along with this work; if not, write to the Free Software Foundation, | |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. | |
| * | |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA | |
| * or visit www.oracle.com if you need additional information or have any | |
| * questions. | |
| */ | |
| package java.lang; | |
| import jdk.internal.misc.CDS; | |
| import jdk.internal.vm.annotation.IntrinsicCandidate; | |
| import jdk.internal.vm.annotation.Stable; | |
| import java.lang.constant.Constable; | |
| import java.lang.constant.DynamicConstantDesc; | |
| import java.util.Optional; | |
| import static java.lang.constant.ConstantDescs.BSM_EXPLICIT_CAST; | |
| import static java.lang.constant.ConstantDescs.CD_byte; | |
| import static java.lang.constant.ConstantDescs.CD_int; | |
| import static java.lang.constant.ConstantDescs.DEFAULT_NAME; | |
| /** | |
| * The {@code Byte} class is the {@linkplain | |
| * java.lang##wrapperClass wrapper class} for values of the primitive | |
| * type {@code byte}. 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}. | |
| * | |
| * <p>This is a <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a> | |
| * class; programmers should treat instances that are | |
| * {@linkplain #equals(Object) equal} as interchangeable and should not | |
| * use instances for synchronization, or unpredictable behavior may | |
| * occur. For example, in a future release, synchronization may fail. | |
| * | |
| * @author Nakul Saraiya | |
| * @author Joseph D. Darcy | |
| * @see java.lang.Number | |
| * @since 1.1 | |
| */ | |
| @jdk.internal.ValueBased | |
| public final class Byte extends Number implements Comparable<Byte>, Constable { | |
| /** | |
| * 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 {@code byte} can | |
| * have, 2<sup>7</sup>-1. | |
| */ | |
| public static final byte MAX_VALUE = 127; | |
| /** | |
| * The {@code Class} instance representing the primitive type | |
| * {@code byte}. | |
| */ | |
| public static final Class<Byte> TYPE = Class.getPrimitiveClass("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(b); | |
| } | |
| /** | |
| * Returns an {@link Optional} containing the nominal descriptor for this | |
| * instance. | |
| * | |
| * @return an {@link Optional} describing the {@linkplain Byte} instance | |
| * @since 15 | |
| */ | |
| @Override | |
| public Optional<DynamicConstantDesc<Byte>> describeConstable() { | |
| return Optional.of(DynamicConstantDesc.ofNamed(BSM_EXPLICIT_CAST, DEFAULT_NAME, CD_byte, intValue())); | |
| } | |
| private static final class ByteCache { | |
| private ByteCache() {} | |
| @Stable | |
| static final Byte[] cache; | |
| static Byte[] archivedCache; | |
| static { | |
| final int size = -(-128) + 127 + 1; | |
| // Load and use the archived cache if it exists | |
| CDS.initializeFromArchive(ByteCache.class); | |
| if (archivedCache == null) { | |
| Byte[] c = new Byte[size]; | |
| byte value = (byte)-128; | |
| for(int i = 0; i < size; i++) { | |
| c[i] = new Byte(value++); | |
| } | |
| archivedCache = c; | |
| } | |
| cache = archivedCache; | |
| assert cache.length == size; | |
| } | |
| } | |
| /** | |
| * 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 | |
| */ | |
| @IntrinsicCandidate | |
| public static Byte valueOf(byte b) { | |
| final int offset = 128; | |
| return ByteCache.cache[(int)b + offset]; | |
| } | |
| /** | |
| * 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 {@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 {@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 Byte.valueOf(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 {@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 Byte.valueOf(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 {@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 {@jls 3.10.1} of | |
| * <cite>The Java 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 {@code Byte}. | |
| * | |
| * @serial | |
| */ | |
| private final byte value; | |
| /** | |
| * 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 {@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 {@code Byte} as a | |
| * {@code byte}. | |
| */ | |
| @IntrinsicCandidate | |
| public byte byteValue() { | |
| return value; | |
| } | |
| /** | |
| * Returns the value of this {@code Byte} as a {@code short} after | |
| * a widening primitive conversion. | |
| * @jls 5.1.2 Widening Primitive Conversion | |
| */ | |
| public short shortValue() { | |
| return (short)value; | |
| } | |
| /** | |
| * Returns the value of this {@code Byte} as an {@code int} after | |
| * a widening primitive conversion. | |
| * @jls 5.1.2 Widening Primitive Conversion | |
| */ | |
| public int intValue() { | |
| return (int)value; | |
| } | |
| /** | |
| * Returns the value of this {@code Byte} as a {@code long} after | |
| * a widening primitive conversion. | |
| * @jls 5.1.2 Widening Primitive Conversion | |
| */ | |
| public long longValue() { | |
| return (long)value; | |
| } | |
| /** | |
| * Returns the value of this {@code Byte} as a {@code float} after | |
| * a widening primitive conversion. | |
| * @jls 5.1.2 Widening Primitive Conversion | |
| */ | |
| public float floatValue() { | |
| return (float)value; | |
| } | |
| /** | |
| * Returns the value of this {@code Byte} as a {@code double} | |
| * after a widening primitive conversion. | |
| * @jls 5.1.2 Widening Primitive Conversion | |
| */ | |
| public double doubleValue() { | |
| return (double)value; | |
| } | |
| /** | |
| * 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 10. | |
| */ | |
| @Override | |
| public String toString() { | |
| return Integer.toString(value); | |
| } | |
| /** | |
| * 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 {@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 | |
| * {@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 b) { | |
| return value == b.byteValue(); | |
| } | |
| return false; | |
| } | |
| /** | |
| * 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 {@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 {@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 {@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 {@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 {@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 {@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 */ | |
| @java.io.Serial | |
| private static final long serialVersionUID = -7183698231559129828L; | |
| } |