libjava/java/lang/Number.java

   1 /* Number.java =- abstract superclass of numeric objects
   2    Copyright (C) 1998, 2001, 2002, 2005  Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38
  39 package java.lang;
  40
  41 import java.io.Serializable;
  42
  43 /**
  44  * Number is a generic superclass of all the numeric classes, including
  45  * the wrapper classes {@link Byte}, {@link Short}, {@link Integer},
  46  * {@link Long}, {@link Float}, and {@link Double}.  Also worth mentioning
  47  * are the classes in {@link java.math}.
  48  *
  49  * It provides ways to convert numeric objects to any primitive.
  50  *
  51  * @author Paul Fisher
  52  * @author John Keiser
  53  * @author Warren Levy
  54  * @author Eric Blake (ebb9@email.byu.edu)
  55  * @since 1.0
  56  * @status updated to 1.4
  57  */
  58 public abstract class Number implements Serializable
  59 {
  60   /**
  61    * Compatible with JDK 1.1+.
  62    */
  63   private static final long serialVersionUID = -8742448824652078965L;
  64
  65   /**
  66    * Table for calculating digits, used in Character, Long, and Integer.
  67    */
  68   static final char[] digits = {
  69     '0', '1', '2', '3', '4', '5', '6', '7', '8', '9',
  70     'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j',
  71     'k', 'l', 'm', 'n', 'o', 'p', 'q', 'r', 's', 't',
  72     'u', 'v', 'w', 'x', 'y', 'z',
  73   };
  74
  75   /**
  76    * The basic constructor (often called implicitly).
  77    */
  78   public Number()
  79   {
  80   }
  81
  82   /**
  83    * Return the value of this <code>Number</code> as an <code>int</code>.
  84    *
  85    * @return the int value
  86    */
  87   public abstract int intValue();
  88
  89   /**
  90    * Return the value of this <code>Number</code> as a <code>long</code>.
  91    *
  92    * @return the long value
  93    */
  94   public abstract long longValue();
  95
  96   /**
  97    * Return the value of this <code>Number</code> as a <code>float</code>.
  98    *
  99    * @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 }