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 }