java中double型数据的加减乘除

雨童

public class Arith { private static final int DEF_DIV_SCALE = 10; /** * 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 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 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 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 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 b1.divide(b2,scale,BigDecimal.ROUND_HALF_UP).doubleValue(); } }