Java实现获取并格式化日期：年月日与时分秒

01.package com.ob;  
02.  
03.import java.text.ParseException;  
04.import java.text.SimpleDateFormat;  
05.import java.util.Calendar;  
06.import java.util.Date;  
07.  
08.public class DateTest {  
09.  
10.    public static void main(String[] args) throws ParseException {  
11.        Calendar now = Calendar.getInstance();  
12.        System.out.println("年: " + now.get(Calendar.YEAR));  
13.        System.out.println("月: " + (now.get(Calendar.MONTH) + 1) + "");  
14.        System.out.println("日: " + now.get(Calendar.DAY_OF_MONTH));  
15.        System.out.println("时: " + now.get(Calendar.HOUR_OF_DAY));  
16.        System.out.println("分: " + now.get(Calendar.MINUTE));  
17.        System.out.println("秒: " + now.get(Calendar.SECOND));  
18.        System.out.println("当前时间毫秒数：" + now.getTimeInMillis());  
19.        System.out.println(now.getTime());  
20.  
21.        Date d = new Date();  
22.        System.out.println(d);  
23.        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
24.        String dateNowStr = sdf.format(d);  
25.        System.out.println("格式化后的日期：" + dateNowStr);  
26.          
27.        String str = "2012-1-13 17:26:33";  //要跟上面sdf定义的格式一样  
28.        Date today = sdf.parse(str);  
29.        System.out.println("字符串转成日期：" + today);  
30.    }