1 /*

     2  * Copyright 1994-2001 Sun Microsystems, Inc.  All Rights Reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Sun designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Sun in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    22  * CA 95054 USA or visit www.sun.com if you need additional information or

    23  * have any questions.

    24  */

    25 

    26 package java.lang;

    27 

    28 /**

    29  * The abstract class <code>Number</code> is the superclass of classes

    30  * <code>BigDecimal</code>, <code>BigInteger</code>,

    31  * <code>Byte</code>, <code>Double</code>, <code>Float</code>,

    32  * <code>Integer</code>, <code>Long</code>, and <code>Short</code>.

    33  * <p>

    34  * Subclasses of <code>Number</code> must provide methods to convert

    35  * the represented numeric value to <code>byte</code>, <code>double</code>,

    36  * <code>float</code>, <code>int</code>, <code>long</code>, and

    37  * <code>short</code>.

    38  *

    39  * @author      Lee Boynton

    40  * @author      Arthur van Hoff

    41  * @see     java.lang.Byte

    42  * @see     java.lang.Double

    43  * @see     java.lang.Float

    44  * @see     java.lang.Integer

    45  * @see     java.lang.Long

    46  * @see     java.lang.Short

    47  * @since   JDK1.0

    48  */

    49 public abstract class Number implements java.io.Serializable {

    50     /**

    51      * Returns the value of the specified number as an <code>int</code>.

    52      * This may involve rounding or truncation.

    53      *

    54      * @return  the numeric value represented by this object after conversion

    55      *          to type <code>int</code>.

    56      */

    57     public abstract int intValue();

    58 

    59     /**

    60      * Returns the value of the specified number as a <code>long</code>.

    61      * This may involve rounding or truncation.

    62      *

    63      * @return  the numeric value represented by this object after conversion

    64      *          to type <code>long</code>.

    65      */

    66     public abstract long longValue();

    67 

    68     /**

    69      * Returns the value of the specified number as a <code>float</code>.

    70      * This may involve rounding.

    71      *

    72      * @return  the numeric value represented by this object after conversion

    73      *          to type <code>float</code>.

    74      */

    75     public abstract float floatValue();

    76 

    77     /**

    78      * Returns the value of the specified number as a <code>double</code>.

    79      * This may involve rounding.

    80      *

    81      * @return  the numeric value represented by this object after conversion

    82      *          to type <code>double</code>.

    83      */

    84     public abstract double doubleValue();

    85 

    86     /**

    87      * Returns the value of the specified number as a <code>byte</code>.

    88      * This may involve rounding or truncation.

    89      *

    90      * @return  the numeric value represented by this object after conversion

    91      *          to type <code>byte</code>.

    92      * @since   JDK1.1

    93      */

    94     public byte byteValue() {

    95         return (byte)intValue();

    96     }

    97 

    98     /**

    99      * Returns the value of the specified number as a <code>short</code>.

   100      * This may involve rounding or truncation.

   101      *

   102      * @return  the numeric value represented by this object after conversion

   103      *          to type <code>short</code>.

   104      * @since   JDK1.1

   105      */

   106     public short shortValue() {

   107         return (short)intValue();

   108     }

   109 

   110     /** use serialVersionUID from JDK 1.0.2 for interoperability */

   111     private static final long serialVersionUID = -8742448824652078965L;

   112 }