/*
 * Copyright (c) 1996, 2013, 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.HotSpotIntrinsicCandidate;
import jdk.internal.misc.VM;

/**
 *
 * 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 {@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}.
 */
 @SuppressWarnings("unchecked")
 public static final Class<Byte> TYPE = (Class<Byte>) 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((int)b, 10);
 }

 private static class ByteCache {
 private ByteCache() {}

 static final Byte[] cache;
 static Byte[] archivedCache;

 static {
 final int size = -(-128) + 127 + 1;

 // Load and use the archived cache if it exists
 VM.initializeFromArchive(ByteCache.class);
 if (archivedCache == null || archivedCache.length != size) {
 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;
 }
 }

 /**
 * 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 {@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 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 {@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 {@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 {@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}.
 */
 @HotSpotIntrinsicCandidate
 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 Conversions
 */
 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 Conversions
 */
 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 Conversions
 */
 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 Conversions
 */
 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 Conversions
 */
 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&nbsp;10.
 */
 public String toString() {
 return Integer.toString((int)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) {
 return value == ((Byte)obj).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 */
 private static final long serialVersionUID = -7183698231559129828L;
}