java 比较时间

1. import java.text.DateFormat;
2. import java.text.ParseException;
3. import java.util.Date;
4.
5. /**
6. * @description 計算两个日期相差的天数
7. * @author ZhouJingxian
8. *
9. */
10. public class CountDate {
11.
12. /**
13. * @param args
14. */
15. public static void main(String[] args) {
16. Date earlydate = new Date();
17. Date latedate = new Date();
18. DateFormat df = DateFormat.getDateInstance();
19. try {
20. earlydate = df.parse("2009-07-01" );
21. latedate = df.parse("2009-08-05" );
22. } catch (ParseException e) {
23. e.printStackTrace();
24. }
25.
26. int days = daysBetween(earlydate,latedate);
27.
28. System.out.println(days);
29. }
30.
31. /**
32. * 計算两个日期相差的天数
33. * @param early 開始日期
34. * @param late 結束日期
35. * @return
36. */
37. public static final int daysBetween(Date early, Date late) {
38. java.util.Calendar calst = java.util.Calendar.getInstance();
39. java.util.Calendar caled = java.util.Calendar.getInstance();
40. calst.setTime(early);
41. caled.setTime(late);
42. //设置时间为0 时
43. calst.set(java.util.Calendar.HOUR_OF_DAY, 0 );
44. calst.set(java.util.Calendar.MINUTE, 0 );
45. calst.set(java.util.Calendar.SECOND, 0 );
46. caled.set(java.util.Calendar.HOUR_OF_DAY, 0 );
47. caled.set(java.util.Calendar.MINUTE, 0 );
48. caled.set(java.util.Calendar.SECOND, 0 );
49.
50. //得到两个日期相差的天数
51. int days = ((int) (caled.getTime().getTim