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));
        
    }
}