Number.java

/*
 * @(#)Number.java	1.34 06/10/10
 *
 * Copyright  1990-2008 Sun Microsystems, Inc. All Rights Reserved.  
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER  
 *   
 * This program is free software; you can redistribute it and/or  
 * modify it under the terms of the GNU General Public License version  
 * 2 only, as published by the Free Software Foundation.   
 *   
 * This program is distributed in the hope that it will be useful, but  
 * WITHOUT ANY WARRANTY; without even the implied warranty of  
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU  
 * General Public License version 2 for more details (a copy is  
 * included at /legal/license.txt).   
 *   
 * You should have received a copy of the GNU General Public License  
 * version 2 along with this work; if not, write to the Free Software  
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  
 * 02110-1301 USA   
 *   
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa  
 * Clara, CA 95054 or visit www.sun.com if you need additional  
 * information or have any questions. 
 *
 */

package java.lang;

/**
 * The abstract class <code>Number</code> is the superclass of classes
 * <code>BigDecimal</code>, <code>BigInteger</code>,
 * <code>Byte</code>, <code>Double</code>, <code>Float</code>,
 * <code>Integer</code>, <code>Long</code>, and <code>Short</code>.
 * NOTE: <B>java.math.BigDecimal</B> is found in J2ME CDC profiles such as 
 * J2ME Foundation Profile.
 * <p>
 * Subclasses of <code>Number</code> must provide methods to convert 
 * the represented numeric value to <code>byte</code>, <code>double</code>,
 * <code>float</code>, <code>int</code>, <code>long</code>, and
 * <code>short</code>.
 *
 * @author	Lee Boynton
 * @author	Arthur van Hoff
 * @version 1.25, 02/02/00
 * @see     java.lang.Byte
 * @see     java.lang.Double
 * @see     java.lang.Float
 * @see     java.lang.Integer
 * @see     java.lang.Long
 * @see     java.lang.Short
 * @since   JDK1.0
 */
public abstract class Number implements java.io.Serializable {
    /**
     * Returns the value of the specified number as an <code>int</code>.
     * This may involve rounding or truncation.
     *
     * @return  the numeric value represented by this object after conversion
     *          to type <code>int</code>.
     */
    public abstract int intValue();

    /**
     * Returns the value of the specified number as a <code>long</code>.
     * This may involve rounding or truncation.
     *
     * @return  the numeric value represented by this object after conversion
     *          to type <code>long</code>.
     */
    public abstract long longValue();

    /**
     * Returns the value of the specified number as a <code>float</code>.
     * This may involve rounding.
     *
     * @return  the numeric value represented by this object after conversion
     *          to type <code>float</code>.
     */
    public abstract float floatValue();

    /**
     * Returns the value of the specified number as a <code>double</code>.
     * This may involve rounding.
     *
     * @return  the numeric value represented by this object after conversion
     *          to type <code>double</code>.
     */
    public abstract double doubleValue();

    /**
     * Returns the value of the specified number as a <code>byte</code>.
     * This may involve rounding or truncation.
     *
     * @return  the numeric value represented by this object after conversion
     *          to type <code>byte</code>.
     * @since   JDK1.1
     */
    public byte byteValue() {
	return (byte)intValue();
    }

    /**
     * Returns the value of the specified number as a <code>short</code>.
     * This may involve rounding or truncation.
     *
     * @return  the numeric value represented by this object after conversion
     *          to type <code>short</code>.
     * @since   JDK1.1
     */
    public short shortValue() {
	return (short)intValue();
    }

    /** use serialVersionUID from JDK 1.0.2 for interoperability */
    private static final long serialVersionUID = -8742448824652078965L;
}