001 /* Number.java =- abstract superclass of numeric objects
002 Copyright (C) 1998, 2001, 2002, 2005 Free Software Foundation, Inc.
003
004 This file is part of GNU Classpath.
005
006 GNU Classpath is free software; you can redistribute it and/or modify
007 it under the terms of the GNU General Public License as published by
008 the Free Software Foundation; either version 2, or (at your option)
009 any later version.
010
011 GNU Classpath is distributed in the hope that it will be useful, but
012 WITHOUT ANY WARRANTY; without even the implied warranty of
013 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
014 General Public License for more details.
015
016 You should have received a copy of the GNU General Public License
017 along with GNU Classpath; see the file COPYING. If not, write to the
018 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019 02110-1301 USA.
020
021 Linking this library statically or dynamically with other modules is
022 making a combined work based on this library. Thus, the terms and
023 conditions of the GNU General Public License cover the whole
024 combination.
025
026 As a special exception, the copyright holders of this library give you
027 permission to link this library with independent modules to produce an
028 executable, regardless of the license terms of these independent
029 modules, and to copy and distribute the resulting executable under
030 terms of your choice, provided that you also meet, for each linked
031 independent module, the terms and conditions of the license of that
032 module. An independent module is a module which is not derived from
033 or based on this library. If you modify this library, you may extend
034 this exception to your version of the library, but you are not
035 obligated to do so. If you do not wish to do so, delete this
036 exception statement from your version. */
037
038
039 package java.lang;
040
041 import java.io.Serializable;
042
043 /**
044 * Number is a generic superclass of all the numeric classes, including
045 * the wrapper classes {@link Byte}, {@link Short}, {@link Integer},
046 * {@link Long}, {@link Float}, and {@link Double}. Also worth mentioning
047 * are the classes in {@link java.math}.
048 *
049 * It provides ways to convert numeric objects to any primitive.
050 *
051 * @author Paul Fisher
052 * @author John Keiser
053 * @author Warren Levy
054 * @author Eric Blake (ebb9@email.byu.edu)
055 * @since 1.0
056 * @status updated to 1.4
057 */
058 public abstract class Number implements Serializable
059 {
060 /**
061 * Compatible with JDK 1.1+.
062 */
063 private static final long serialVersionUID = -8742448824652078965L;
064
065 /**
066 * Table for calculating digits, used in Character, Long, and Integer.
067 */
068 static final char[] digits = {
069 '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
070 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
071 'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
072 'u', 'v', 'w', 'x', 'y', 'z',
073 };
074
075 /**
076 * The basic constructor (often called implicitly).
077 */
078 public Number()
079 {
080 }
081
082 /**
083 * Return the value of this <code>Number</code> as an <code>int</code>.
084 *
085 * @return the int value
086 */
087 public abstract int intValue();
088
089 /**
090 * Return the value of this <code>Number</code> as a <code>long</code>.
091 *
092 * @return the long value
093 */
094 public abstract long longValue();
095
096 /**
097 * Return the value of this <code>Number</code> as a <code>float</code>.
098 *
099 * @return the float value
100 */
101 public abstract float floatValue();
102
103 /**
104 * Return the value of this <code>Number</code> as a <code>float</code>.
105 *
106 * @return the double value
107 */
108 public abstract double doubleValue();
109
110 /**
111 * Return the value of this <code>Number</code> as a <code>byte</code>.
112 *
113 * @return the byte value
114 * @since 1.1
115 */
116 public byte byteValue()
117 {
118 return (byte) intValue();
119 }
120
121 /**
122 * Return the value of this <code>Number</code> as a <code>short</code>.
123 *
124 * @return the short value
125 * @since 1.1
126 */
127 public short shortValue()
128 {
129 return (short) intValue();
130 }
131 }