Java计算金额精度问题

Floating Point Math

http://0.30000000000000004.com/

Java计算金额工具类

import java.math.BigDecimal;

public class MathUtils {

    public static Double add(Double val1, Double val2, int scale) {
        if (null == val1) {
            val1 = new Double(0);
        }
        if (null == val2) {
            val2 = new Double(0);
        }
        return new BigDecimal(Double.toString(val1)).add(new BigDecimal(Double.toString(val2)))
                .setScale(scale, BigDecimal.ROUND_HALF_UP).doubleValue();
    }

    public static Double addAll(Double[] vals, int scale) {
        BigDecimal result = new BigDecimal("0");
        for (Double val : vals) {
            if(val == null) continue;
            result = result.add(new BigDecimal(Double.toString(val))).setScale(scale, BigDecimal.ROUND_HALF_UP);
        }
        return result.doubleValue();
    }

    public static Double subtract(Double val1, Double val2, int scale) {
        if (null == val1) {
            val1 = new Double(0);
        }
        if (null == val2) {
            val2 = new Double(0);
        }
        return new BigDecimal(Double.toString(val1)).subtract(new BigDecimal(Double.toString(val2)))
                .setScale(scale, BigDecimal.ROUND_HALF_UP).doubleValue();
    }

    public static Double multiply(Double val1, Double val2, int scale) {
        if (null == val1) {
            val1 = new Double(0);
        }
        if (null == val2) {
            val2 = new Double(0);
        }
        return new BigDecimal(Double.toString(val1)).multiply(new BigDecimal(Double.toString(val2)))
                .setScale(scale, BigDecimal.ROUND_HALF_UP).doubleValue();
    }

    public static Double divide(Double val1, Double val2, int scale) {
        if (null == val1) {
            val1 = new Double(0);
        }
        if (null == val2 || val2 == 0) {
            val2 = new Double(1);
        }
        return new BigDecimal(Double.toString(val1)).divide(new BigDecimal(Double.toString(val2)))
                .setScale(scale, BigDecimal.ROUND_HALF_UP).doubleValue();
    }
}