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);
}