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Executing code when process finishes

Posted on 2004-10-05
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Last Modified: 2010-03-31
Hi all,

I have an application which starts by reading data from a file.  When it ends, I want it to write data to the file, ready for next time.

What is the best way to do this?  More specifically:

1) How do I make the application execute code on quitting

and

2) Whats the best way to write over data in a file?  Delete the file then create a new one?
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Question by:agrees
8 Comments
 
LVL 86

Expert Comment

by:CEHJ
ID: 12229559
1. You can make the application run the ccode at the end of main
2. Nothing special required - the file will be overwritten anyway
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Author Comment

by:agrees
ID: 12229703
> 1. You can make the application run the ccode at the end of main

It's has a GUI so the application ends when the user closes one of the windows in a sequence of windows I create.  

My current best is idea to add a windowclosed listener to all the windows, but is there a better way?

2. Nothing special required - the file will be overwritten anyway

ok, so just something like this?:

    try {
        BufferedWriter out = new BufferedWriter(new FileWriter("outfilename"));
        out.write(myData);
        out.close();
    } catch (IOException e) {
    }

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LVL 86

Assisted Solution

by:CEHJ
CEHJ earned 80 total points
ID: 12229730
>>My current best is idea to add a windowclosed listener to all the windows, but is there a better way?

Good idea

2. Yes, that'll do fine
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LVL 92

Expert Comment

by:objects
ID: 12232412
Create an exit method that saves your file and exits the application.
Then whenever an event occurs that should close the application (eg. exit selected in menu) then call that exit() method.
0
 

Expert Comment

by:ranaanju
ID: 12234807
1. write your code at the end of the main function  in the finally block.
2. open file in the write mode, it will automatically delete if it exist and create it as new file.
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LVL 24

Accepted Solution

by:
sciuriware earned 420 total points
ID: 12235209
Yet another solution: add a shutdown thread to your program,
just in case you exit from an unexpected spot:

     Runtime.getRuntime().addShutdownHook(new Rip());

    ......


    public class Rip extends Thread
    {
   // what must be done when I die ....
    }

;JOOP!
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Expert Comment

by:CEHJ
ID: 12242417
8-)
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Expert Comment

by:sciuriware
ID: 12246138
What kind of expression is that CEHJ?  :<)
;JOOP!
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