Date与Calendar

package com.java.test;

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

public class DateTest {
  public static void main(String [] args)
  {
/* System.out.println(new Date());
  System.out.println(new Date().toString());
  //标准的java类库分别包含了俩个类：一个是用来表示时间点的Date类，一个是用来表示大家都熟悉的日历表示法的GregorianCalendar类
  //将日期与日历分开是一种很好的的面向对象设计。通常，最好使用不同的类表示不同的概念。
  GregorianCalendar GC=new GregorianCalendar(1999,11,31);
  System.out.println(GC);
  //如何利用日历来提供某个时间点的年月日等信息，这里要用到GregorianCalendar的get方法，以及Calendar的Month、DAY_OF_WEEk等属性;
  GregorianCalendar GC1=new GregorianCalendar();
  int year=GC1.get(Calendar.YEAR);
  int month=GC1.get(Calendar.MONTH);
  int week=GC1.get(Calendar.WEEK_OF_MONTH);
  int date=GC1.get(Calendar.DAY_OF_WEEK);
  System.out.println("现在是"+year+"年,"+month+"月，第"+week+"周的第"+date+"天，");
  //这里我们先Date与Calendar二者彼此的转换
  Calendar cl=Calendar.getInstance();
  cl.clear();*/
  Calendar calendar = new GregorianCalendar();
  Date trialTime = new Date();
  calendar.setTime(trialTime);//
calendar.add(calendar.DAY_OF_MONTH, -6);
Calendar cl=Calendar.getInstance();
cl.add(cl.DAY_OF_MONTH, +3);
//System.out.println("Date"+cl.get(Calendar.DATE));
System.out.println(((GregorianCalendar) cl).isLeapYear(Calendar.YEAR));

//Date 与Calendar的转换，Calendar转换成Date用 getTime()方法，Date转化成Calendar用setTime()方法
  Calendar cld=Calendar.getInstance();
  Date date=new Date();
  cld.clear();
cld.set(Calendar.YEAR, 2011);
cld.set(Calendar.MONTH, 4);
cld.set(Calendar.DATE, 7);
Date date1=cld.getTime();
System.out.println(date1);
//下面是Date如何转化成Calendar
Date date2=new Date();
Calendar cld1=Calendar.getInstance();
cld1.clear();
cld1.setTime(date2);
System.out.println(cld1);



// print out a bunch of interesting things
  System.out.println("ERA: " + calendar.get(Calendar.ERA));
  System.out.println("YEAR: " + calendar.get(Calendar.YEAR));
  System.out.println("MONTH: " + calendar.get(Calendar.MONTH));
  System.out.println("WEEK_OF_YEAR: " + calendar.get(Calendar.WEEK_OF_YEAR));
  System.out.println("WEEK_OF_MONTH: " + calendar.get(Calendar.WEEK_OF_MONTH));
  System.out.println("DATE: " + calendar.get(Calendar.DATE));
  System.out.println("DAY_OF_MONTH: " + calendar.get(Calendar.DAY_OF_MONTH));
  System.out.println("DAY_OF_YEAR: " + calendar.get(Calendar.DAY_OF_YEAR));
  System.out.println("DAY_OF_WEEK: " + calendar.get(Calendar.DAY_OF_WEEK));
  System.out.println("DAY_OF_WEEK_IN_MONTH: " + calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH));
  System.out.println("AM_PM: " + calendar.get(Calendar.AM_PM));
  System.out.println("HOUR: " + calendar.get(Calendar.HOUR));
  System.out.println("HOUR_OF_DAY: " + calendar.get(Calendar.HOUR_OF_DAY));
  System.out.println("MINUTE: " + calendar.get(Calendar.MINUTE));
  System.out.println("SECOND: " + calendar.get(Calendar.SECOND));
  System.out.println("MILLISECOND: " + calendar.get(Calendar.MILLISECOND));
  System.out.println("ZONE_OFFSET: " + (calendar.get(Calendar.ZONE_OFFSET)/(60*60*1000)));
  System.out.println("DST_OFFSET: " + (calendar.get(Calendar.DST_OFFSET)/(60*60*1000)));

  System.out.println("Current Time, with hour reset to 3");
  calendar.clear(Calendar.HOUR_OF_DAY); // so doesn't override
  calendar.set(Calendar.HOUR, 3);
  System.out.println("ERA: " + calendar.get(Calendar.ERA));
  System.out.println("YEAR: " + calendar.get(Calendar.YEAR));
  System.out.println("MONTH: " + calendar.get(Calendar.MONTH));
  System.out.println("WEEK_OF_YEAR: " + calendar.get(Calendar.WEEK_OF_YEAR));
  System.out.println("WEEK_OF_MONTH: " + calendar.get(Calendar.WEEK_OF_MONTH));
  System.out.println("DATE: " + calendar.get(Calendar.DATE));
  System.out.println("DAY_OF_MONTH: " + calendar.get(Calendar.DAY_OF_MONTH));
  System.out.println("DAY_OF_YEAR: " + calendar.get(Calendar.DAY_OF_YEAR));
  System.out.println("DAY_OF_WEEK: " + calendar.get(Calendar.DAY_OF_WEEK));
  System.out.println("DAY_OF_WEEK_IN_MONTH: " + calendar.get(Calendar.DAY_OF_WEEK_IN_MONTH));
  System.out.println("AM_PM: " + calendar.get(Calendar.AM_PM));
  System.out.println("HOUR: " + calendar.get(Calendar.HOUR));
  System.out.println("HOUR_OF_DAY: " + calendar.get(Calendar.HOUR_OF_DAY));
  System.out.println("MINUTE: " + calendar.get(Calendar.MINUTE));
  System.out.println("SECOND: " + calendar.get(Calendar.SECOND));
  System.out.println("MILLISECOND: " + calendar.get(Calendar.MILLISECOND));
  System.out.println("ZONE_OFFSET: " + (calendar.get(Calendar.ZONE_OFFSET)/(60*60*1000))); // in hours
  System.out.println("DST_OFFSET: " + (calendar.get(Calendar.DST_OFFSET)/(60*60*1000))); // in hours
  }

 
   }