java保留两位小数4种方法

http://blog.sina.com.cn/s/blog_4f925fc3010181ty.html

import java.math.BigDecimal;

import java.text.DecimalFormat;

import java.text.NumberFormat;

public class format {

double f = 111231.5585;

public void m1() {

BigDecimal bg = new BigDecimal(f);

double f1 = bg.setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue();

System.out.println(f1);

}

public void m2() {

DecimalFormat df = new DecimalFormat("#.00");

System.out.println(df.format(f));

}

public void m3() {

System.out.println(String.format("%.2f", f));

}

public void m4() {

NumberFormat nf = NumberFormat.getNumberInstance();

nf.setMaximumFractionDigits(2);

System.out.println(nf.format(f));

}

public static void main(String[] args) {

format f = new format();

f.m1();

f.m2();

f.m3();

f.m4();

}

}

结果：

111231.56

111231.56

111231.56

111,231.56