记录一下

/***
 * 计算两个日期之间的间隔天數
 */
Calendar fromCalendar = Calendar.getInstance();
Date startDate = new Date(2014, 11, 20);
fromCalendar.setTime(startDate); 
fromCalendar.set(Calendar.HOUR_OF_DAY, 0);  
fromCalendar.set(Calendar.MINUTE, 0);  
fromCalendar.set(Calendar.SECOND, 0);  
fromCalendar.set(Calendar.MILLISECOND, 0);  

Calendar toCalendar = Calendar.getInstance();
Date endDate = new Date(2014, 10, 20);
fromCalendar.setTime(startDate);
toCalendar.setTime(endDate);
toCalendar.set(Calendar.HOUR_OF_DAY, 0);
toCalendar.set(Calendar.MINUTE, 0);
toCalendar.set(Calendar.SECOND, 0);
toCalendar.set(Calendar.MILLISECOND, 0);

System.out.println((toCalendar.getTime().getTime() - fromCalendar
        .getTime().getTime()) / (1000 * 60 * 60 * 24));

 

			







import java.text.DateFormat;

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.Date;

import java.util.Scanner;


public class DateDemo

{

 

 

 public static void main(String [] args) throws
ParseException

 {

  

  

  Scanner in = new
Scanner(System.in);

  System.out.println("请输入第一个日期（格式为:年-月-日）：");


  String date1 =
in.nextLine();

  System.out.println("请输入第二个日期（格式为:年-月-日）：");


  String date2 =
in.nextLine();

  

    
test(date1,date2);

  

 }

//  用来计算两个日期之间相差的毫秒数

 public static void test(String date1,String
date2) throws ParseException

   {

  DateFormat df =
DateFormat.getDateInstance();

  df= new
SimpleDateFormat("yyyy-MM-dd");

  

  Date date_1 =
df.parse(date1);

  Date date_2 =
df.parse(date2);

  

  long time1 =
date_1.getTime();

  long time2 =
date_2.getTime();

  long time3 =
Math.abs(time1-time2);

  

  int day = getDay(time3);

    
System.out.println("两日期相隔"+day+"天");

   }

//将两个日期之间的毫秒数换算成天数

 private static int getDay(long time)

 {

  int day =
(int)(time/1000/60/60/24);

  return day;

 }

}
							
		

java 计算两个时间之间的间隔
http://blog.csdn.net/cynhafa/article/details/8053166
 
以某种方式表现
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//设置日期格式
System.out.println(df.format(new Date()));// new Date()为获取当前系统时间
 
获取两个时间的差
秒  （time1.getTime()-time2.getTime）/1000
.getTime()获得的是毫秒，/1000是秒，/60是分钟，/60是小时，/24是天

public static String getDatePoor(Date endDate, Date nowDate) {
 
    long nd = 1000 * 24 * 60 * 60;
    long nh = 1000 * 60 * 60;
    long nm = 1000 * 60;
    // long ns = 1000;
    // 获得两个时间的毫秒时间差异
    long diff = endDate.getTime() - nowDate.getTime();
    // 计算差多少天
    long day = diff / nd;
    // 计算差多少小时
    long hour = diff % nd / nh;
    // 计算差多少分钟
    long min = diff % nd % nh / nm;
    // 计算差多少秒//输出结果
    long sec = diff % nd % nh % nm / ns;
    return day + "天" + hour + "小时" + min + "分钟" + sec +"秒";
}