Java 计算两个日期相差月数、天数

package com.myjava;

import java.text.ParseException;

import java.text.SimpleDateFormat;

import java.util.Calendar;

public class MyCalendar {

/**

* @param args

* @throws ParseException

*/

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

System.out.println(MyCalendar.getMonthSpace("1982-12-8", "2012-12-12"));

}

/**

*

* @param date1 <String>

* @param date2 <String>

* @return int

* @throws ParseException

*/

public static int getMonthSpace(String date1, String date2)

throws ParseException {

int result = 0;

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

Calendar c1 = Calendar.getInstance();

Calendar c2 = Calendar.getInstance();

c1.setTime(sdf.parse(date1));

c2.setTime(sdf.parse(date2));

result = c2.get(Calendar.MONTH) - c1.get(Calendar.MONTH);

return result == 0 ? 1 : Math.abs(result);

}

}

* @param date1 <String>

* @param date2 <String>

* @return int

* @throws ParseException

*/

public int getDateSpace(String date1, String date2)

throws ParseException {

int result = 0;

Calendar calst = Calendar.getInstance();;

Calendar caled = Calendar.getInstance();

calst.setTime(parseDate("yyyyMMdd",date1));

caled.setTime(parseDate("yyyyMMdd",date2));

//设置时间为0时

calst.set(Calendar.HOUR_OF_DAY, 0);

calst.set(Calendar.MINUTE, 0);

calst.set(Calendar.SECOND, 0);

caled.set(Calendar.HOUR_OF_DAY, 0);

caled.set(Calendar.MINUTE, 0);

caled.set(Calendar.SECOND, 0);

//得到两个日期相差的天数

int days = ((int)(caled.getTime().getTime()/1000)-(int)(calst.getTime().getTime()/1000))/3600/24;

return days;

}

public static final int daysBetween(Date early, Date late) {

java.util.Calendar calst = java.util.Calendar.getInstance();

java.util.Calendar caled = java.util.Calendar.getInstance();

calst.setTime(early);

caled.setTime(late);

//设置时间为0时

calst.set(java.util.Calendar.HOUR_OF_DAY, 0);

calst.set(java.util.Calendar.MINUTE, 0);

calst.set(java.util.Calendar.SECOND, 0);

caled.set(java.util.Calendar.HOUR_OF_DAY, 0);

caled.set(java.util.Calendar.MINUTE, 0);

caled.set(java.util.Calendar.SECOND, 0);

//得到两个日期相差的天数

int days = ((int) (caled.getTime().getTime() / 1000) - (int) (calst

.getTime().getTime() / 1000)) / 3600 / 24;

return days;

}

public static void main(String[] args)

{

Date earlydate = new Date();

Date latedate = new Date();

DateFormat df = DateFormat.getDateInstance();

try {

earlydate = df.parse("2009-09-21");

latedate = df.parse("2009-10-16");

} catch (ParseException e) {

e.printStackTrace();

}

int days = daysBetween(earlydate,latedate);

System.out.println(days);

}