java.util.Date problem

[Ronnie Ho]

  
System.out.println(beginDate.equals(selectedDate));
System.out.println(beginDate.getTime());
System.out.println(selectedDate.getTime());

Results:
false
1127793600000
1127793600000

Both beginDate and selectedDate are of type java.util.Date. Can someone explain the result? According to the API:

two Date objects are equal if and only if the getTime method returns the same long value for both.

[Ernest Friedman-Hill]

Well, where do the Date objects come from?

[Ronnie Ho]

  
SimpleDateFormat format = new SimpleDateFormat("MM/dd/yyyy");
Date selectedDate = format.parse(dateString); //dateString is a String 
 
beginDate is from the database (oracle).
 
Both are in type java.util.Date. According to the API, they should be equal, right?
 

[Ernest Friedman-Hill]

You'd think. The one from the database is probably a java.sql.Date, which is a subclass of java.util.Date. Still, they should compare equal if getTime() reports the same number.

[Bimal Patel]

Hi,

Can you try using compareTo(<Date object> . If the result is 0, the two dates are equal. I don't know why equal is not working . This may help you.

[Stuart Ash]

There are two possible alternatives to this:

a. Create calendar objects and compare the relevant fields of the calendar instances (day, month, year...).

b. Change the code to something like

int tolerableDifference = 24 * 60 * 60 * 1000; // milliseconds
return Math.abs(beginDate.getTime() - selectedDate.getTime()) < tolerableDifference;

Here, it should return true only if they represent the same date upto the day. (Caution: This algorithm might need some testing/debugging thow.)

Perhaps the first one is preferable.

Hope this helps.

[Akshay Kiran]

I don't know why your code is not working, but I can offer a workaround.

Just try
Date begindate2= new Date(beginDate.getTime());

and then

selectedDate.equals(begindate2);