Java中Date类与Calendar类

public class NewMain {
    public static void main(String[] args) {
    	ShowDate phc=new ShowDate();
        phc.printCurrentDate();
        phc.setTimeInMillis(1234567898765L);
 	}
}

import java.util.Calendar;

public class ShowDate {
    
    public  void printCurrentDate(){
        Calendar now = Calendar.getInstance(); //获取一个日历对象
        System.out.println("当前年: " + now.get(Calendar.YEAR)); //调用get方法，获取当前年、月、日
        System.out.println("当前月: " + (now.get(Calendar.MONTH)+1) +"");
        System.out.println("当前日: " + now.get(Calendar.DAY_OF_MONTH));
    }
    
    public void setTimeInMillis(long millis){
        Calendar date=Calendar.getInstance();
        date.setTimeInMillis(millis); //给定的long 值设置成为基准时间值
        System.out.println("指定日期的年"+date.get(Calendar.YEAR));//调用get方法，获取以基准时间为标准的当前年、月、日
        System.out.println("指定日期的月"+date.get(Calendar.MONTH));
        System.out.println("指定日期的日"+date.get(Calendar.DAY_OF_MONTH));
    }
}