1 /*
2 * Copyright (c) 1994, 2001, Oracle and/or its affiliates. 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. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * 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 }