Java格式化日期

1.背景

在Java项目中格式化日期是很常见的，那么对于每一个匹配模式就应该有所了解才能在实际项目中游刃有余。

2.匹配模式详解

字符 解释                    例子
G   Era designator          AD
y   Year                    1996; 96
Y   Week year   Year        2009; 09
M   Month in year           July; Jul; 07
w   Week in year            27
W   Week in month           2
D   Day in year             189
d   Day in month            10
F   Day of week in month    2
E   Day name in week        Tuesday; Tue
u   Day number of week (1 = Monday, ..., 7 = Sunday)    1
a   Am/pm marker            PM
H   Hour in day (0-23)      0
k   Hour in day (1-24)      24
K   Hour in am/pm (0-11)    0
h   Hour in am/pm (1-12)    12
m   Minute in hour          30
s   Second in minute        55
S   Millisecond             978
z   Time zone               PST; GMT-08:00
Z   Time zone               -0800
X   Time zone               -08; -0800; -08:00

3.具体使用

package com.ds.domain;

import java.text.SimpleDateFormat;
import java.util.Date;

public class DS {

    public static void main(String[] args) {
        Date date = new Date();
        SimpleDateFormat sFormat = new SimpleDateFormat();
        //2016-03-16 16:12:19.239
        sFormat.applyPattern("yyyy-MM-dd HH:mm:ss.SS");
        //2016-03-16 04:11:41
        //实际位数大于定义位数，则往前面补0，如此处的小时04，月份03
        sFormat.applyPattern("yyyy-MM-dd KK:mm:ss");
        System.out.println(sFormat.format(date));
    }

}