java 数字格式化 NumberFormat类的使用

package com.meixin.classuse;
import java.text.NumberFormat;
public class DefaultNumberFormat
{
public static void defaultNumberFormat()
{
int i = 123456;
double x = 882323.23523;
double p = 0.528;
double c = 52.83;

System.out.println("--------------------------------------");
//实例化NumberFormat需要使用NumberFormat的getInstance()方法
NumberFormat nf = NumberFormat.getInstance();
//默认格式化int类型，结果已分节
//结果：Integer 123456 is displayed as 123,456
System.out.println("Integer " + i + " is displayed as " + nf.format(i));
//默认格式化double类型，结果保留三位小数，已分节
//结果：Double 882323.23523 is displayed as 882,323.235
System.out.println("Double " + x + " is displayed as " + nf.format(x));

System.out.println("--------------------------------------");
//实例化为整型数据格式化
NumberFormat nfInt = NumberFormat.getIntegerInstance();
//默认，结果：Integer 123456 is displayed as 123,456
System.out.println("Integer " + i + " is displayed as "
+ nfInt.format(i));

System.out.println("--------------------------------------");
//实例化为数据格式化
NumberFormat nfNumber = NumberFormat.getNumberInstance();
//结果：Double 882323.23523 is displayed as 882,323.235
System.out.println("Double " + x + " is displayed as "
+ nfNumber.format(x));

System.out.println("--------------------------------------");
//百分数格式化
NumberFormat nfPercent = NumberFormat.getPercentInstance();
//结果已四舍五入
//结果：Percent 0.528 is displayed as 53%
System.out.println("Percent " + p + " is displayed as "
+ nfPercent.format(p));
System.out.println("--------------------------------------");

//货币型格式化
NumberFormat nfCurrency = NumberFormat.getCurrencyInstance();
//结果：Currency 52.83 is displayed as ￥52.83
System.out.println("Currency " + c + " is displayed as "
+ nfCurrency.format(c));
}

public static void main(String[] args)
{
defaultNumberFormat();
System.out.println();
}
}

package com.meixin.classuse;
import java.text.DecimalFormat;
public class CustomNumberFormat
{
public static void customNumberFormat()
{
double x = 100000.0 / 3;
// default output is 33333.333333333336
System.out.println("default output is " + x);
// 33,333.33
System.out.println(new DecimalFormat("###,###.##").format(x));
// 33333.33
System.out.println(new DecimalFormat("####.##").format(x));
// 33333.33
System.out.println(new DecimalFormat("####.00").format(x));
// 33333.33
System.out.println(new DecimalFormat("####.0#").format(x));
// 0033333.33
System.out.println(new DecimalFormat("0000000.##").format(x));
// $33,333.33
System.out.println(new DecimalFormat("$###,###.##").format(x));
// 3.333E4
System.out.println(new DecimalFormat("0.###E0").format(x));
// 3333333.33%
System.out.println(new DecimalFormat("00.##%").format(x));
System.out.println("--------------------------------------");
double y = 23232323.0012;
//default output is 2.32323230012E7
System.out.println("default output is " + y);
//23,232,323
System.out.println(new DecimalFormat("###,###.##").format(y));
//23232323
System.out.println(new DecimalFormat("####.##").format(y));
//23232323.00
System.out.println(new DecimalFormat("####.00").format(y));
//23232323.0
System.out.println(new DecimalFormat("####.0#").format(y));
//0023232323
System.out.println(new DecimalFormat("0000000000.##").format(y));
//$23,232,323
System.out.println(new DecimalFormat("$###,###.##").format(y));
//2.323E7
System.out.println(new DecimalFormat("0.###E0").format(y));
//2323232300.12%
System.out.println(new DecimalFormat("00.##%").format(y));
}
public static void main(String[] args)
{
customNumberFormat();
System.out.println();
}
}