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 } | 1 /* 2 * Copyright (c) 1994, 2011, 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} is the superclass of platform 30 * classes representing numeric values that are convertible to the 31 * primitive types {@code byte}, {@code double}, {@code float}, {@code 32 * int}, {@code long}, and {@code short}. 33 * 34 * The specific semantics of the conversion from the numeric value of 35 * a particular {@code Number} implementation to a given primitive 36 * type is defined by the {@code Number} implementation in question. 37 * 38 * For platform classes, the conversion is often analogous to a 39 * narrowing primitive conversion or a widening primitive conversion 40 * as defining in <cite>The Java™ Language Specification</cite> 41 * for converting between primitive types. Therefore, conversions may 42 * lose information about the overall magnitude of a numeric value, may 43 * lose precision, and may even return a result of a different sign 44 * than the input. 45 * 46 * See the documentation of a given {@code Number} implementation for 47 * conversion details. 48 * 49 * @author Lee Boynton 50 * @author Arthur van Hoff 51 * @jls 5.1.2 Widening Primitive Conversions 52 * @jls 5.1.3 Narrowing Primitive Conversions 53 * @since JDK1.0 54 */ 55 public abstract class Number implements java.io.Serializable { 56 /** 57 * Returns the value of the specified number as an {@code int}, 58 * which may involve rounding or truncation. 59 * 60 * @return the numeric value represented by this object after conversion 61 * to type {@code int}. 62 */ 63 public abstract int intValue(); 64 65 /** 66 * Returns the value of the specified number as a {@code long}, 67 * which may involve rounding or truncation. 68 * 69 * @return the numeric value represented by this object after conversion 70 * to type {@code long}. 71 */ 72 public abstract long longValue(); 73 74 /** 75 * Returns the value of the specified number as a {@code float}, 76 * which may involve rounding. 77 * 78 * @return the numeric value represented by this object after conversion 79 * to type {@code float}. 80 */ 81 public abstract float floatValue(); 82 83 /** 84 * Returns the value of the specified number as a {@code double}, 85 * which may involve rounding. 86 * 87 * @return the numeric value represented by this object after conversion 88 * to type {@code double}. 89 */ 90 public abstract double doubleValue(); 91 92 /** 93 * Returns the value of the specified number as a {@code byte}, 94 * which may involve rounding or truncation. 95 * 96 * <p>This implementation returns the result of {@link #intValue} cast 97 * to a {@code byte}. 98 * 99 * @return the numeric value represented by this object after conversion 100 * to type {@code byte}. 101 * @since JDK1.1 102 */ 103 public byte byteValue() { 104 return (byte)intValue(); 105 } 106 107 /** 108 * Returns the value of the specified number as a {@code short}, 109 * which may involve rounding or truncation. 110 * 111 * <p>This implementation returns the result of {@link #intValue} cast 112 * to a {@code short}. 113 * 114 * @return the numeric value represented by this object after conversion 115 * to type {@code short}. 116 * @since JDK1.1 117 */ 118 public short shortValue() { 119 return (short)intValue(); 120 } 121 122 /** use serialVersionUID from JDK 1.0.2 for interoperability */ 123 private static final long serialVersionUID = -8742448824652078965L; 124 } |