Stream problem when I export my project in a .jar executable archive

[Arsenicmic]

Hello everyone,
My problem is that I have made a program that use Output and Input Streams for saving data in a file. While I try it in my IDE (NetBeans 6.7.1) everything works perfectly well. But when I try to use my .jar executable, my program works well but can't read nor write data’s!
Have somebody an idea why it doesn't work ?
Thanks for your answers

P.S. I beg your indulgence for my English. I speak French and have never had any English course …the most English I learned is from javaDoc ;-)

[Fubarable]

Mr. Poison:

Your English is fine, so please don't worry about that.

I am no expert in Applets but I do know that to read and write files from a host machine requires proper permissions (a "signed" applet). Question: must this application be an applet? Also, what do your I and O routines look like? Are you looking for the files in the correct locations? And what error messages do you get?

Best of luck!

[mrmatt1111]

Writting: You cannot easily write data to a jar file (though it can be done). If you write to a file it is easier to save it onto the host machine. If you want to know where that is:

File file = new File("");
System.out.println(file.getAbsolutePath());

Reading:

You can open a data file in a jar but you must give the path of that data file otherwise it doesn't know where to look.

You can derive the path by using an object's class information:

System.out.println(this.getClass().getResource("")); //see jar path for this class

File file = null;
try
{
   file = new File(this.getClass().getResource("resources/myFile.txt").toString()); //adjust the directory and file name can use ".." to back a directory if need be
}
catch(Exception e)
{
   System.out.println("This File doesn't exist!");
}

[Arsenicmic]

Thanks, really!
I didn't expect to get so quick answers. And I want to apologize for answering still now, because in fact, I did realize one or two day after that my problem was my own stupidity! The directory in witch I export my projects have been renamed (certainly a mistake of mine) so that I have been trying the same old version (in witch there was a problem of IO streams that I solved)!!!! And in the meantime, my corrected version was waiting me in a secret place of my computer!
So I am truly sorry for wasting your time, and happily surprised of how quick you can get answers here. (It was my first post on a forum... for a first one, that's not a true success!)
So thank you very much
Arsenic Mic