java开发中常用的数字工具类

import java.math.BigDecimal;
import org.apache.commons.lang.RandomStringUtils;

public class NumberUtil {

private static final int DEF_DIV_SCALE = 2;

/**
* 判断字符串是否为数字
* @param num
* @return
*/
public static boolean isNumberic(String num){
return (null == num || num.length() <= 0 || num.matches("\\d{1,}")) ? true : false;
}

/**
* @return 返回12位随机数
*/
public static String randomNumber()
{
return RandomStringUtils.randomNumeric(12);
}
/**
* @param parm
* @return 返回指定位数随机数
*/
public static String randomNumber(int parm)
{
return RandomStringUtils.randomNumeric(parm);
}
/**
* @return 返回纯数字和字母的GUID
*/
public static String randomUUID()
{
return GuidUtil.randomGuidUtil().toString().replaceAll("-","");
}
/**
* @param parm
* @return 返回指定位数的GUID
*/
public static String randomUUID(int parm)
{
return GuidUtil.randomGuidUtil().toString().replaceAll("-","").substring(0,parm);
}

/**
* * 两个Double数相加 *
*
* @param v1 *
* @param v2 *
* @return Double
*/
public static Double add(Double v1, Double v2) {
BigDecimal b1 = new BigDecimal(v1.toString());
BigDecimal b2 = new BigDecimal(v2.toString());
return new Double(b1.add(b2).doubleValue());
}

/**
* * 两个Double数相减 *
*
* @param v1 *
* @param v2 *
* @return Double
*/
public static Double sub(Double v1, Double v2) {
BigDecimal b1 = new BigDecimal(v1.toString());
BigDecimal b2 = new BigDecimal(v2.toString());
return new Double(b1.subtract(b2).doubleValue());
}

/**
* * 两个Double数相乘 *
*
* @param v1 *
* @param v2 *
* @return Double
*/
public static Double mul(Double v1, Double v2) {
BigDecimal b1 = new BigDecimal(v1.toString());
BigDecimal b2 = new BigDecimal(v2.toString());
return new Double(b1.multiply(b2).doubleValue());
}

/**
* * 两个Double数相除 *
*
* @param v1 *
* @param v2 *
* @return Double
*/
public static Double div(Double v1, Double v2) {
BigDecimal b1 = new BigDecimal(v1.toString());
BigDecimal b2 = new BigDecimal(v2.toString());
return new Double(b1
.divide(b2, DEF_DIV_SCALE, BigDecimal.ROUND_HALF_UP)
.doubleValue());
}

/**
* * 两个Double数相除，并保留scale位小数 *
*
* @param v1 *
* @param v2 *
* @param scale *
* @return Double
*/
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(v1.toString());
BigDecimal b2 = new BigDecimal(v2.toString());
return new Double(b1.divide(b2, scale, BigDecimal.ROUND_HALF_UP)
.doubleValue());
}

/**
* @param v1
* @return 返回指定Double的负数
*/
public static Double neg(Double v1) {
return sub(new Double(0),v1);
}

}