package?com.abstracted.demo;

import?java.text.ParseException;
import?java.text.SimpleDateFormat;
import?java.util.Calendar;
import?java.util.Date;

public?class?Datetest?{
	public?static?void?main(String?[]args)?throws?ParseException{
	//將日期轉換為指定格式輸出
???Date?date?=?new?Date();
???SimpleDateFormat?simpleDateFormat?=?new?SimpleDateFormat("yyyy-mm-dd?HH:MM:SS");
???String?date1?=?simpleDateFormat.format(date);
???System.out.println(date1);
???//字符串日期轉換成日期格式輸出
???SimpleDateFormat?simpleDateFormat1?=?new?SimpleDateFormat("yyyy-mm-dd?HH:MM:SS");?
???Date?date2?=simpleDateFormat1.parse(date1);
???System.out.println(date2);
???
???
???
???Calendar??c?=?Calendar.getInstance();
???System.out.println(c.getTime());??//每刷新一次時間秒數會發生對應的改變?Date類構建的日期的秒數不變
???int?year?=?c.get(Calendar.YEAR);
???int?month?=?c.get(Calendar.MONTH);
???int?day?=?c.get(Calendar.DAY_OF_MONTH);
???int?hour?=?c.get(Calendar.HOUR);
???int?minute?=?c.get(Calendar.MINUTE);
???int?second?=?c.get(Calendar.SECOND);
???System.out.println("當前時間："+year?+?"-"?+?month+"-"?+?day?+"?"+?hour+":"?+?minute+":"+second);
???System.out.println(c.getTimeInMillis());

	}
}

控制臺打出：

2016-24-03?11:03:490
Thu?Mar?03?11:24:00?CST?2016
Thu?Mar?03?11:24:51?CST?2016
當前時間：2016-2-3?11:24:51
1456975491505

結論 ：

Calendar每刷新一次時間的秒數會發生對應的改變 Date類構建的日期的秒數不變