java计算两日期间隔天数

package com.color.program;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
public class CompareTime {
public static void main(String[] args){
String t1 = "2008-05-09";
String t2 = "2008-5-13";
try {
System.out.println(CompareTime.getBetweenDays(t1, t2));
} catch (ParseException e) {
e.printStackTrace();
}
}
/**
* 取得两个时间段的时间间隔
* return t2 与t1的间隔天数
* throws ParseException 如果输入的日期格式不是0000-00-00 格式抛出异常
*/
public static int getBetweenDays(String t1,String t2) throws ParseException{
DateFormat format = new SimpleDateFormat("yyyy-MM-dd");
int betweenDays = 0;
Date d1 = format.parse(t1);
Date d2 = format.parse(t2);
Calendar c1 = Calendar.getInstance();
Calendar c2 = Calendar.getInstance();
c1.setTime(d1);
c2.setTime(d2);
// 保证第二个时间一定大于第一个时间
if(c1.after(c2)){
c1 = c2;
c2.setTime(d1);
}
int betweenYears = c2.get(Calendar.YEAR)-c1.get(Calendar.YEAR);
betweenDays = c2.get(Calendar.DAY_OF_YEAR)-c1.get(Calendar.DAY_OF_YEAR);
for(int i=0;i<betweenYears;i++){
c1.set(Calendar.YEAR,(c1.get(Calendar.YEAR)+1));
betweenDays += c1.getMaximum(Calendar.DAY_OF_YEAR);
}
return betweenDays;
}
}