Calendar类常用的方法

    import java.util.*;
public class Datedemo{

    public static void main(String[] args){
      // 1.GregorianCalendar() 
     // 2.在具有默认语言环境的默认时区内使用当前时间构造一个默认的 GregorianCalendar。

        Calendar calendar=new GregorianCalendar();  
        calendar.set(2016,12,30,1,3,3);
        System.out.println(calendar);

        //1.构造一个calendar1时间
        Calendar calendar1=new GregorianCalendar();
          calendar1.setTime(new Date());
          System.out.println(calendar1);

          //2.月份向后移动四个月;
          //add(int field, int amount) 
           //根据日历的规则，为给定的日历字段添加或减去指定的时间量。

          calendar1.add(Calendar.MONTH,4);
          System.out.println(calendar1);
          //3.get(int field)
          //返回给定日历字段的值。

          int MONTH=calendar1.get(Calendar.MONTH);
          int year=calendar1.get(Calendar.YEAR);
            System.out.println("YEAR"+year+"MONTH"+MONTH);

          //4.Date getTime() 
          //返回一个表示此 Calendar 时间值（从历元至现在的毫秒偏移量）的 Date 对象。
           Date date=calendar1.getTime();
           System.out.println(date);

    }

}

运行结果：
java.util.GregorianCalendar[time=?,areFieldsSet=false,areAllFieldsSet=true,lenie
nt=true,zone=sun.util.calendar.ZoneInfo[id=”Asia/Shanghai”,offset=28800000,dstSa
vings=0,useDaylight=false,transitions=19,lastRule=null],firstDayOfWeek=1,minimal
DaysInFirstWeek=1,ERA=1,YEAR=2016,MONTH=12,WEEK_OF_YEAR=53,WEEK_OF_MONTH=5,DAY_O
F_MONTH=30,DAY_OF_YEAR=365,DAY_OF_WEEK=6,DAY_OF_WEEK_IN_MONTH=5,AM_PM=1,HOUR=5,H
OUR_OF_DAY=1,MINUTE=3,SECOND=3,MILLISECOND=381,ZONE_OFFSET=28800000,DST_OFFSET=0
]
java.util.GregorianCalendar[time=1483089287381,areFieldsSet=true,areAllFieldsSet
=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id=”Asia/Shanghai”,offset=288
00000,dstSavings=0,useDaylight=false,transitions=19,lastRule=null],firstDayOfWee
k=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2016,MONTH=11,WEEK_OF_YEAR=53,WEEK_OF_MO
NTH=5,DAY_OF_MONTH=30,DAY_OF_YEAR=365,DAY_OF_WEEK=6,DAY_OF_WEEK_IN_MONTH=5,AM_PM
=1,HOUR=5,HOUR_OF_DAY=17,MINUTE=14,SECOND=47,MILLISECOND=381,ZONE_OFFSET=2880000
0,DST_OFFSET=0]
java.util.GregorianCalendar[time=?,areFieldsSet=false,areAllFieldsSet=true,lenie
nt=true,zone=sun.util.calendar.ZoneInfo[id=”Asia/Shanghai”,offset=28800000,dstSa
vings=0,useDaylight=false,transitions=19,lastRule=null],firstDayOfWeek=1,minimal
DaysInFirstWeek=1,ERA=1,YEAR=2017,MONTH=3,WEEK_OF_YEAR=53,WEEK_OF_MONTH=5,DAY_OF
_MONTH=30,DAY_OF_YEAR=365,DAY_OF_WEEK=6,DAY_OF_WEEK_IN_MONTH=5,AM_PM=1,HOUR=5,HO
UR_OF_DAY=17,MINUTE=14,SECOND=47,MILLISECOND=381,ZONE_OFFSET=28800000,DST_OFFSET
=0]

YEAR2017MONTH3

Sun Apr 30 17:14:47 CST 2017