Transferred from http://hi.baidu.com/czjjzhao/blog/item/a9cc55017272d8d8267fb5bd.html
DateFormat df = new SimpleDateFormat ("Yyyy-mm-dd HH:mm:ss");
try {Date D1 = df.parse ("2004-03-26 13:31:40");
Date D2 = Df.parse ("2004-01-02 11:30:24");
Long diff = d1.gettime ()-d2.gettime ();
Long days = diff/(1000 * 60 * 60 * 24);
The catch (Exception e) {} method two: SimpleDateFormat df = new SimpleDateFormat ("Yyyy-mm-dd HH:mm:ss");
Java.util.Date now = Df.parse ("2004-03-26 13:31:40");
Java.util.Date date=df.parse ("2004-01-02 11:30:24");
Long L=now.gettime ()-date.gettime ();
Long day=l/(24*60*60*1000);
Long hour= (l/(60*60*1000)-day*24);
Long min= ((l/(60*1000))-day*24*60-hour*60);
Long s= (l/1000-day*24*60*60-hour*60*60-min*60);
System.out.println ("" +day+ "Day" +hour+ "hour" +min+ "minute" +s+ "seconds");
Method III: SimpleDateFormat DFS = new SimpleDateFormat ("Yyyy-mm-dd HH:mm:ss");
Java.util.Date begin=dfs.parse ("2004-01-02 11:30:24");
Java.util.Date end = Dfs.parse ("2004-03-26 13:31:40"); Long between= (End.gettime ()-begin.gettime ())/1000;//divided by 1000 to convert to a second long day1=between/(24*3600);
Long hour1=between% (24*3600)/3600;
Long minute1=between%3600/60;
Long second1=between%60/60;
System.out.println ("" +day1+ "Day" +hour1+ "hour" +minute1+ "minute" +second1+ "seconds");
==================================================== Java comparison time size String s1= "2008-01-25 09:12:09";
String s2= "2008-01-29 09:12:11";
Java.text.DateFormat df=new Java.text.SimpleDateFormat ("Yyyy-mm-dd HH:mm:ss");
Java.util.Calendar c1=java.util.calendar.getinstance ();
Java.util.Calendar c2=java.util.calendar.getinstance ();
try {c1.settime (Df.parse (S1));
C2.settime (Df.parse (S2));
}catch (java.text.ParseException e) {System.err.println ("malformed");
int Result=c1.compareto (C2);
if (result==0) System.out.println ("C1 equal C2");
else if (result<0) System.out.println ("C1 less than C2");
Else System.out.println ("C1 greater than C2"); Time format conversion Fastdateformat df = FastdateformaT.getinstance ("Yyyy-mm-dd HH:mm:ss"); String date = Df.format (Java.util.Date ());