How to stop a threads that makes I/O calls ?

Hi,
I've a business method that calls a Stored Procedure and makes lots of calculations. This method works inside its own thread, because I do not want to stop the GUI from accepting user actions.
My problem is : this method may take from 5 minutes to 1 hour to process, depending on the size of the input. Sometimes, for any reason at all, the user may want to stop this execution (pressing a button on the GUI). How can I safely stop the thread ?
I know I should not use stop() and suspend() because they are deprecated. And I do not use loops (remember it calls only a StoredProcedure that makes all processing), so I cannot use a variable nor interrupt(), because they do not work.
Do you know any other way to stop this thread's execution ? By the way destroy() is not implemented.
Thanks and regards.
Bruno

Are you saying that the 5 minutes to an hour is all spent in the stored procedure?
If so the only real solution is to kill the statement - I'm not sure how the DB will handle that, but it will certainly free up your cycles.
To do that without violating encapsulation, you just need to keep a reference to an object that knows something about the DB connection - you don't have to actually pass around the JDBC objects.
Consider an object like this:
public class DoLongProcedure {
   private Statement dbStatement;
   public double doLongCalculation() {
      dbStatement.execute(...);
      // etc
   public void interruptCalculation() {
      dbStatement.close();
}You create an instance of this object and call its doLongCalculation() method to start everything. You have a reference to this object somewhere, because you are waiting for a response. When the user wants to cancel the process you just call the interruptCalculation() method.
You have not violated your separation of functionality - if you find a new way to stop the process without killing the statement later, you just reimplement that method.

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Edited by: ELStefen on 26-ago-2010 16.08
Edited by: ELStefen on 26-ago-2010 16.11

isocdev_mb wrote:
Using a synchronized-block is not designed to give up the lock for little while, it holds the lock until the block ends. Your requirement needs a far more fine-grained approach, quite different from your sketched implementation.
It would involve quite an amount of guessing of what's behind the G and c your mentioning to suggest a way out. Please elaborate on what you're trying to achieve so that we can suggest how to do that...
P.S. this forum likes problems to come with a simple working example, which you did not provide and a description of what you'd like to achieve, some context.as i thought, damn.
Well give a working example is quite complex for the time being. Is a big project and take out this part is quite complex. But i can explain the goal.
Practically there's a Graph (G)
this graph is used by 2 thread, one is the update the edges and vertices, adding and removing them. the other one thread is the painter of the graph.
the problem is when the first thread is updating the structure of G, sometimes this operation takes time (seconds) and being synchronized on G it blocks the paint thread as well.
the thing that i would like to have is keep the painting working each tot millisecond. the updating thread works when necessary. if the update operation takes to long, it has to be stopped in the middle (and it has to restart after the paint) in a way that the paint thread can be executed.
as the code is, and as you said, synchronizing the entire block code cannot works as i want.
is this more clear? any clue about how can i solve this?
many thanks
Edited by: ELStefen on 27-ago-2010 12.43

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http://developer.java.sun.com/developer/technicalArticles/Networking/timeouts/

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