| /* Byte.java -- object wrapper for byte |
| Copyright (C) 1998, 2001, 2002, 2005 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package java.lang; |
| |
| /** |
| * Instances of class <code>Byte</code> represent primitive <code>byte</code> |
| * values. |
| * |
| * Additionally, this class provides various helper functions and variables |
| * useful to bytes. |
| * |
| * @author Paul Fisher |
| * @author John Keiser |
| * @author Per Bothner |
| * @author Eric Blake (ebb9@email.byu.edu) |
| * @since 1.1 |
| * @status updated to 1.5 |
| */ |
| public final class Byte extends Number implements Comparable |
| { |
| /** |
| * Compatible with JDK 1.1+. |
| */ |
| private static final long serialVersionUID = -7183698231559129828L; |
| |
| /** |
| * The minimum value a <code>byte</code> can represent is -128 (or |
| * -2<sup>7</sup>). |
| */ |
| public static final byte MIN_VALUE = -128; |
| |
| /** |
| * The maximum value a <code>byte</code> can represent is 127 (or |
| * 2<sup>7</sup> - 1). |
| */ |
| public static final byte MAX_VALUE = 127; |
| |
| /** |
| * The primitive type <code>byte</code> is represented by this |
| * <code>Class</code> object. |
| */ |
| public static final Class TYPE = VMClassLoader.getPrimitiveClass('B'); |
| |
| /** |
| * The number of bits needed to represent a <code>byte</code>. |
| * @since 1.5 |
| */ |
| public static final int SIZE = 8; |
| |
| // This caches Byte values, and is used by boxing conversions via |
| // valueOf(). We're required to cache all possible values here. |
| private static Byte[] byteCache = new Byte[MAX_VALUE - MIN_VALUE + 1]; |
| |
| /** |
| * The immutable value of this Byte. |
| * |
| * @serial the wrapped byte |
| */ |
| private final byte value; |
| |
| /** |
| * Create a <code>Byte</code> object representing the value of the |
| * <code>byte</code> argument. |
| * |
| * @param value the value to use |
| */ |
| public Byte(byte value) |
| { |
| this.value = value; |
| } |
| |
| /** |
| * Create a <code>Byte</code> object representing the value specified |
| * by the <code>String</code> argument |
| * |
| * @param s the string to convert |
| * @throws NumberFormatException if the String does not contain a byte |
| * @see #valueOf(String) |
| */ |
| public Byte(String s) |
| { |
| value = parseByte(s, 10); |
| } |
| |
| /** |
| * Converts the <code>byte</code> to a <code>String</code> and assumes |
| * a radix of 10. |
| * |
| * @param b the <code>byte</code> to convert to <code>String</code> |
| * @return the <code>String</code> representation of the argument |
| */ |
| public static String toString(byte b) |
| { |
| return String.valueOf(b); |
| } |
| |
| /** |
| * Converts the specified <code>String</code> into a <code>byte</code>. |
| * This function assumes a radix of 10. |
| * |
| * @param s the <code>String</code> to convert |
| * @return the <code>byte</code> value of <code>s</code> |
| * @throws NumberFormatException if <code>s</code> cannot be parsed as a |
| * <code>byte</code> |
| * @see #parseByte(String) |
| */ |
| public static byte parseByte(String s) |
| { |
| return parseByte(s, 10); |
| } |
| |
| /** |
| * Converts the specified <code>String</code> into an <code>int</code> |
| * using the specified radix (base). The string must not be <code>null</code> |
| * or empty. It may begin with an optional '-', which will negate the answer, |
| * provided that there are also valid digits. Each digit is parsed as if by |
| * <code>Character.digit(d, radix)</code>, and must be in the range |
| * <code>0</code> to <code>radix - 1</code>. Finally, the result must be |
| * within <code>MIN_VALUE</code> to <code>MAX_VALUE</code>, inclusive. |
| * Unlike Double.parseDouble, you may not have a leading '+'. |
| * |
| * @param s the <code>String</code> to convert |
| * @param radix the radix (base) to use in the conversion |
| * @return the <code>String</code> argument converted to <code>byte</code> |
| * @throws NumberFormatException if <code>s</code> cannot be parsed as a |
| * <code>byte</code> |
| */ |
| public static byte parseByte(String s, int radix) |
| { |
| int i = Integer.parseInt(s, radix, false); |
| if ((byte) i != i) |
| throw new NumberFormatException(); |
| return (byte) i; |
| } |
| |
| /** |
| * Creates a new <code>Byte</code> object using the <code>String</code> |
| * and specified radix (base). |
| * |
| * @param s the <code>String</code> to convert |
| * @param radix the radix (base) to convert with |
| * @return the new <code>Byte</code> |
| * @throws NumberFormatException if <code>s</code> cannot be parsed as a |
| * <code>byte</code> |
| * @see #parseByte(String, int) |
| */ |
| public static Byte valueOf(String s, int radix) |
| { |
| return new Byte(parseByte(s, radix)); |
| } |
| |
| /** |
| * Creates a new <code>Byte</code> object using the <code>String</code>, |
| * assuming a radix of 10. |
| * |
| * @param s the <code>String</code> to convert |
| * @return the new <code>Byte</code> |
| * @throws NumberFormatException if <code>s</code> cannot be parsed as a |
| * <code>byte</code> |
| * @see #Byte(String) |
| * @see #parseByte(String) |
| */ |
| public static Byte valueOf(String s) |
| { |
| return new Byte(parseByte(s, 10)); |
| } |
| |
| /** |
| * Returns a <code>Byte</code> object wrapping the value. |
| * In contrast to the <code>Byte</code> constructor, this method |
| * will cache some values. It is used by boxing conversion. |
| * |
| * @param val the value to wrap |
| * @return the <code>Byte</code> |
| * |
| * @since 1.5 |
| */ |
| public static Byte valueOf(byte val) |
| { |
| synchronized (byteCache) |
| { |
| if (byteCache[val - MIN_VALUE] == null) |
| byteCache[val - MIN_VALUE] = new Byte(val); |
| return byteCache[val - MIN_VALUE]; |
| } |
| } |
| |
| /** |
| * Convert the specified <code>String</code> into a <code>Byte</code>. |
| * The <code>String</code> may represent decimal, hexadecimal, or |
| * octal numbers. |
| * |
| * <p>The extended BNF grammar is as follows:<br> |
| * <pre> |
| * <em>DecodableString</em>: |
| * ( [ <code>-</code> ] <em>DecimalNumber</em> ) |
| * | ( [ <code>-</code> ] ( <code>0x</code> | <code>0X</code> |
| * | <code>#</code> ) { <em>HexDigit</em> }+ ) |
| * | ( [ <code>-</code> ] <code>0</code> { <em>OctalDigit</em> } ) |
| * <em>DecimalNumber</em>: |
| * <em>DecimalDigit except '0'</em> { <em>DecimalDigit</em> } |
| * <em>DecimalDigit</em>: |
| * <em>Character.digit(d, 10) has value 0 to 9</em> |
| * <em>OctalDigit</em>: |
| * <em>Character.digit(d, 8) has value 0 to 7</em> |
| * <em>DecimalDigit</em>: |
| * <em>Character.digit(d, 16) has value 0 to 15</em> |
| * </pre> |
| * Finally, the value must be in the range <code>MIN_VALUE</code> to |
| * <code>MAX_VALUE</code>, or an exception is thrown. |
| * |
| * @param s the <code>String</code> to interpret |
| * @return the value of the String as a <code>Byte</code> |
| * @throws NumberFormatException if <code>s</code> cannot be parsed as a |
| * <code>byte</code> |
| * @throws NullPointerException if <code>s</code> is null |
| * @see Integer#decode(String) |
| */ |
| public static Byte decode(String s) |
| { |
| int i = Integer.parseInt(s, 10, true); |
| if ((byte) i != i) |
| throw new NumberFormatException(); |
| return new Byte((byte) i); |
| } |
| |
| /** |
| * Return the value of this <code>Byte</code>. |
| * |
| * @return the byte value |
| */ |
| public byte byteValue() |
| { |
| return value; |
| } |
| |
| /** |
| * Return the value of this <code>Byte</code> as a <code>short</code>. |
| * |
| * @return the short value |
| */ |
| public short shortValue() |
| { |
| return value; |
| } |
| |
| /** |
| * Return the value of this <code>Byte</code> as an <code>int</code>. |
| * |
| * @return the int value |
| */ |
| public int intValue() |
| { |
| return value; |
| } |
| |
| /** |
| * Return the value of this <code>Byte</code> as a <code>long</code>. |
| * |
| * @return the long value |
| */ |
| public long longValue() |
| { |
| return value; |
| } |
| |
| /** |
| * Return the value of this <code>Byte</code> as a <code>float</code>. |
| * |
| * @return the float value |
| */ |
| public float floatValue() |
| { |
| return value; |
| } |
| |
| /** |
| * Return the value of this <code>Byte</code> as a <code>double</code>. |
| * |
| * @return the double value |
| */ |
| public double doubleValue() |
| { |
| return value; |
| } |
| |
| /** |
| * Converts the <code>Byte</code> value to a <code>String</code> and |
| * assumes a radix of 10. |
| * |
| * @return the <code>String</code> representation of this <code>Byte</code> |
| * @see Integer#toString() |
| */ |
| public String toString() |
| { |
| return String.valueOf(value); |
| } |
| |
| /** |
| * Return a hashcode representing this Object. <code>Byte</code>'s hash |
| * code is simply its value. |
| * |
| * @return this Object's hash code |
| */ |
| public int hashCode() |
| { |
| return value; |
| } |
| |
| /** |
| * Returns <code>true</code> if <code>obj</code> is an instance of |
| * <code>Byte</code> and represents the same byte value. |
| * |
| * @param obj the object to compare |
| * @return whether these Objects are semantically equal |
| */ |
| public boolean equals(Object obj) |
| { |
| return obj instanceof Byte && value == ((Byte) obj).value; |
| } |
| |
| /** |
| * Compare two Bytes numerically by comparing their <code>byte</code> values. |
| * The result is positive if the first is greater, negative if the second |
| * is greater, and 0 if the two are equal. |
| * |
| * @param b the Byte to compare |
| * @return the comparison |
| * @since 1.2 |
| */ |
| public int compareTo(Byte b) |
| { |
| return value - b.value; |
| } |
| |
| /** |
| * Behaves like <code>compareTo(Byte)</code> unless the Object |
| * is not a <code>Byte</code>. |
| * |
| * @param o the object to compare |
| * @return the comparison |
| * @throws ClassCastException if the argument is not a <code>Byte</code> |
| * @see #compareTo(Byte) |
| * @see Comparable |
| * @since 1.2 |
| */ |
| public int compareTo(Object o) |
| { |
| return compareTo((Byte) o); |
| } |
| } |