日期的使用

1.Calendar和date的转换
ca.setTime(date);

Calendar ca = Calendar.getInstance();
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		try {
			Date date1 = sdf.parse("2012-11-01 12:10:12");
			Date date2 = sdf.parse("2012-11-23 00:00:00");
			ca.setTime(date1);
			long length = (date2.getTime()-date1.getTime())/(1000*60*60*24);
			System.out.println(length);
			for(int i=0;i<=length;i++){
				ca.add(Calendar.DATE, 1);
				int week = ca.get(Calendar.DAY_OF_WEEK);
				if(week == 2){//星期一
					System.out.println("星期一");
				}
				System.out.println(format.format(ca.getTime()));
			}
		} catch (ParseException e) {
			e.printStackTrace();
		}

2.取得时分秒

Calendar ca2 = Calendar.getInstance();
Date date2 = sdf.parse("2012-11-23 19:30:50");
ca2.setTime(date2);
System.out.println(ca2.get(Calendar.SECOND));//秒
System.out.println(ca2.get(Calendar.MINUTE));//分
System.out.println(ca2.get(Calendar.HOUR_OF_DAY));//时