wzw.util.NumberUtils.java Source code

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Here is the source code for wzw.util.NumberUtils.java

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/**
 * Copyright (C) 2002-2007 WUZEWEN. All rights reserved.
 * WUZEWEN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
 * This software is the confidential and proprietary information of
 * WuZeven, Personal. ("Confidential Information").  You shall not
 * disclose such Confidential Information and shall use it only in
 * accordance with the terms of the license agreement you entered into
 * with WuZeven.
 */

package wzw.util;

import java.math.BigDecimal;
import java.util.HashMap;

import org.apache.commons.lang.StringUtils;

/**
 * <p>?????</p>
 * <pre>
 * NumberUtils.add(1.2, 1.32)         =2.52
 * NumberUtils.add(1, 1.122)          =2.122
 * NumberUtils.sub(1.32, 1.2)         =0.12
 * NumberUtils.mul(2,  1.32)          =2.64
 * NumberUtils.div(1.32, 2)           =0.66
 * NumberUtils.div(1.32, 2, 1)        =0.7
 * NumberUtils.round(1.32525, 2)      =1.33
 * NumberUtils.round(1.32525, 3)      =1.325
 * </pre>
 * @author Zeven on 2007-2-10
 * @version   1.0
 * @see      Object#equals(java.lang.Object)
 * @see      Object#hashCode()
 * @see      HashMap
 * @since   JDK5
 */

public class NumberUtils {

    /*
     * ??102?8?16
     */
    private static final int DEF_DIV_SCALE = 10;

    /**
         
     * ???
         
     * @param v1 
         
     * @param v2 
         
     * @return ?
         
     */

    public static double add(double v1, double v2) {

        BigDecimal b1 = new BigDecimal(Double.toString(v1));

        BigDecimal b2 = new BigDecimal(Double.toString(v2));

        return b1.add(b2).doubleValue();

    }

    /**
         
     * ????
         
     * @param v1 ?
         
     * @param v2 ?
         
     * @return ?
         
     */

    public static double sub(double v1, double v2) {

        BigDecimal b1 = new BigDecimal(Double.toString(v1));

        BigDecimal b2 = new BigDecimal(Double.toString(v2));

        return b1.subtract(b2).doubleValue();

    }

    /**
         
     * ???
         
     * @param v1 
         
     * @param v2 
         
     * @return ?
         
     */

    public static double mul(double v1, double v2) {

        BigDecimal b1 = new BigDecimal(Double.toString(v1));

        BigDecimal b2 = new BigDecimal(Double.toString(v2));

        return b1.multiply(b2).doubleValue();

    }

    /**
         
     * ?????
         
     * ??10???
         
     * @param v1 
         
     * @param v2 
         
     * @return ?
         
     */

    public static double div(double v1, double v2) {

        return div(v1, v2, DEF_DIV_SCALE);

    }

    /**
         
     * ?????scale?
         
     * ??
         
     * @param v1 
         
     * @param v2 
         
     * @param scale ????
         
     * @return ?
         
     */

    public static double div(double v1, double v2, int scale) {

        if (scale < 0) {

            throw new IllegalArgumentException("The scale must be a positive integer or zero");

        }

        BigDecimal b1 = new BigDecimal(Double.toString(v1));

        BigDecimal b2 = new BigDecimal(Double.toString(v2));

        return b1.divide(b2, scale, BigDecimal.ROUND_HALF_UP).doubleValue();

    }

    /**
     * 
     * ??????
     * 
     * @param v
     *            ??
     * 
     * @param scale
     *            ????
     * 
     * @return ??
     * 
     */

    public static double round(double v, int scale) {

        if (scale < 0) {

            throw new IllegalArgumentException("The scale must be a positive integer or zero");

        }

        BigDecimal b = new BigDecimal(Double.toString(v));

        BigDecimal one = new BigDecimal("1");

        return b.divide(one, scale, BigDecimal.ROUND_HALF_UP).doubleValue();

    }

    /**
     * @param args
     */
    public static void main(String[] args) {
        // TODO Auto-generated method stub

        //test add
        System.out.println(
                StringUtils.rightPad("NumberUtils.add(1.2, 1.32) ", 35, " ") + "=" + NumberUtils.add(1.2, 1.32));
        System.out.println(
                StringUtils.rightPad("NumberUtils.add(1, 1.122) ", 35, " ") + "=" + NumberUtils.add(1, 1.122));

        //test sub
        System.out.println(
                StringUtils.rightPad("NumberUtils.sub(1.32, 1.2) ", 35, " ") + "=" + NumberUtils.sub(1.32, 1.2));

        //test mul 
        System.out.println(
                StringUtils.rightPad("NumberUtils.mul(2,  1.32) ", 35, " ") + "=" + NumberUtils.mul(2, 1.32));

        //test div
        System.out.println(
                StringUtils.rightPad("NumberUtils.div(1.32, 2) ", 35, " ") + "=" + NumberUtils.div(1.32, 2));
        System.out.println(
                StringUtils.rightPad("NumberUtils.div(1.32, 2, 1) ", 35, " ") + "=" + NumberUtils.div(1.32, 2, 1));

        //test round
        System.out.println(StringUtils.rightPad("NumberUtils.round(1.32525, 2) ", 35, " ") + "="
                + NumberUtils.round(1.32525, 2));
        System.out.println(StringUtils.rightPad("NumberUtils.round(1.32525, 3) ", 35, " ") + "="
                + NumberUtils.round(1.32525, 3));

    }

}