格式化数字

package com.jdk7.chapter3;

import java.text.DecimalFormat;

public class FormatNumber {
    public static void main(String[] args) {
        double data = 1203.405607809;
        DecimalFormat df = new DecimalFormat();
        
        String pattern = "0.0";        //格式
        df.applyPattern(pattern);    //加载格式
        System.out.println(df.format(data));    //按照格式进行格式化
        
        //.表示小数点;0表示对应位置有则显示，无则补0
        pattern = "00000.000 kg";
        df.applyPattern(pattern);
        System.out.println(df.format(data));
        
        //#表示对应位置有则显示，无则不显示
        pattern = "#0000.000 kg";
        df.applyPattern(pattern);
        System.out.println(df.format(data));
        
        pattern = "-0000.000 kg";
        df.applyPattern(pattern);
        System.out.println(df.format(data));
        
        pattern = "0,000.000 kg";
        df.applyPattern(pattern);
        System.out.println(df.format(data));
        
        pattern = "0000.0E0 kg";
        df.applyPattern(pattern);
        System.out.println(df.format(data));
        
        pattern = "0.0%";
        df.applyPattern(pattern);
        System.out.println(df.format(data));
        
        pattern = "0.0u2030";
        df.applyPattern(pattern);
        System.out.println(df.format(data));
    }
}

执行结果：
1203.4
01203.406 kg
1203.406 kg
-1203.406 kg
1,203.406 kg
1203.4E0 kg
120340.6%
1203405.6‰