round double value by scale - Java java.lang

Java examples for java.lang:double

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Description

round double value by scale

Demo Code


//package com.java2s;
import java.math.BigDecimal;

public class Main {
    public static void main(String[] argv) throws Exception {
        double val = 2.45678;
        int scale = 2;
        System.out.println(round(val, scale));
    }//from  w  w  w.  ja v  a 2  s.c o  m

    private static final int DEF_DIV_SCALE = 10;

    public static double round(double val, int scale) {
        if (scale < 0) {
            throw new IllegalArgumentException(
                    "The scale must be a positive integer or zero");
        }
        BigDecimal b = new BigDecimal(Double.toString(val));
        BigDecimal one = new BigDecimal("1");
        return b.divide(one, scale, BigDecimal.ROUND_HALF_UP).doubleValue();

    }

    public static double divide(double dividend, double divisor) {
        return divide(dividend, divisor, DEF_DIV_SCALE);
    }

    public static double divide(double dividend, double divisor, int scale) {
        if (scale < 0) {
            throw new IllegalArgumentException(
                    "The scale must be a positive integer or zero");
        }
        BigDecimal b1 = new BigDecimal(Double.toString(dividend));
        BigDecimal b2 = new BigDecimal(Double.toString(divisor));
        return b1.divide(b2, scale, BigDecimal.ROUND_HALF_UP).doubleValue();
    }
}

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