java计算出两个日期相隔多少天源代码

01.import java.text.SimpleDateFormat; 
02.import java.util.Date; 
03.import org.junit.Test; 
04. 
05.public class T1 { 
06.     
07.    @Test 
08.    public void t(){ 
09.        String before = "2013-5-15"; 
10.        String now = "2013-5-17"; 
11.        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); 
12.        try { 
13.            Date d1 = sdf.parse(before); 
14.            Date d2 = sdf.parse(now); 
15.            long daysBetween = (d2.getTime() - d1.getTime() + 1000000) 
16.                    / (3600 * 24 * 1000); 
17.            System.out.println("相隔："+daysBetween+"天"); 
18.        } catch (Exception e) { 
19.            System.out.println(e.getMessage()); 
20.        } 
21.    } 
22.}