java中Calendar与Date类型互相转换的方法

实现思路:   
    1.Calendar转换为Date借助时间戳为中间桥梁
	 Calendar cal=Calendar.getInstance();  
      Date date=cal.getTime();  
      
    2.Date转化为Calendar,借助Calendar中的setTime方法即可实现相关需求  
    Date date=new Date();  
    Calendar cal=Calendar.getInstance();  
    cal.setTime(date);

package com.java265.other;
import java.util.Calendar;
import java.util.Date;
public class Test {
    
    public static void main(String[] args) throws Exception {
        Date d = new Date(1529991234L * 1000);

        Calendar cal = Calendar.getInstance();
        //Date转Calendar
        cal.setTime(d); 

        //Calendar转换为Date
        Date d2 = cal.getTime();
            System.out.println(d.toString());
            System.out.println("=================");
            System.out.println(d2.toString());
    }
}
--------运行以上代码，将输出以下信息-------
Tue Jun 26 13:33:54 CST 2018
=================
Tue Jun 26 13:33:54 CST 2018

Calendar cal = Calendar.getInstance();
Date date = cal.getTime;

Date date = new Date();
Calendar cal = Calendar.getInstance();
Cal.setTime(date );

String oneHoursAGoTime="";
Date dt = new Date();
SimpleDateFORMat sdf=new SimpleDateFormat("yyyy-MM-dd-HH");
Calendar rightNow = Calendar.getInstance();
rightNow.setTime(dt);
//rightNow.add(Calendar.DATE, -1);
rightNow.add(Calendar.HOUR, -1);
Date dt1=rightNow.getTime();
oneHoursAgoTime = sdf.format(dt1);
return oneHoursAgoTime;