java API 時間相關

getTime():

import java.util.Date;

public class testGetTime {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Date date = new Date();
		System.out.println(date);
		
		//1970年1月1日0時距此刻毫秒數
		long time = date.getTime();
		
		System.out.println(time);
	}

}

setTime():

import java.util.Date;

public class testSetTime {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Date date = new Date();
		System.out.println(date);
		
		//1970年1月1日0時距此刻毫秒數
		long time = date.getTime();
		
		System.out.println(time);
		
		//增加一天所經歷的毫秒數
		time+= 60 * 60 * 24 * 1000;
		
		date.setTime(time);
		
		System.out.println(date);
	}

}

format方法格式化日期：

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

public class testSimpleDateFormat {
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
		Date date = new Date();
		String dateStr = sdf.format(date);
		System.out.println(dateStr);
	}
}

parse：

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

public class testParse {

	/**
	 * @param args
	 * @throws ParseException 
	 */
	public static void main(String[] args) throws ParseException {
		// TODO Auto-generated method stub
		String str = "2013-12-15";
		SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
		Date date = sdf.parse(str);
		System.out.println(date);
	}

}

Calendar：

import java.util.Calendar;
import java.util.GregorianCalendar;

public class testGetInstance {
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Calendar c = Calendar.getInstance();
		//getTime返回date
		System.out.println(c.getTime());
		
		//set
		c.set(Calendar.YEAR, 2013);
		c.set(Calendar.MONTH, Calendar.DECEMBER);
		c.set(Calendar.DATE, 1);
		System.out.println(c.getTime());
		
		//get
		int dayOfWeek = c.get(Calendar.DAY_OF_WEEK);
		System.out.println(dayOfWeek);
		//創建GregorianCalendar對象
		GregorianCalendar c1 = new GregorianCalendar(2014,Calendar.JUNE,25);
		System.out.println(c1.getTime());
	}
}

Date()與Calendar()轉換：

calendar.setTime(date);

date = calendar.getTime();