java 精确获取时分秒

import java.util.Calendar;
 import java.util.GregorianCalendar;
 public class systemdemo {
     public static void main(String[] args) {
         Calendar calendar=null;
         calendar =new GregorianCalendar();//子类实例化
         System.out.println("年： "+calendar.get(Calendar.YEAR));
         System.out.println("月 "+(calendar.get(Calendar.MONTH)+1));
         System.out.println("日： "+calendar.get(Calendar.DAY_OF_MONTH));
         System.out.println("时： "+calendar.get(Calendar.HOUR_OF_DAY));
         System.out.println("分： "+calendar.get(Calendar.MINUTE));
         System.out.println("秒： "+calendar.get(Calendar.SECOND));
         System.out.println("毫秒 "+calendar.get(Calendar.MILLISECOND));
         
     }
 }