Problem with SaveDialog & File extensions

[robertob]

I'm using JFileChooser class and I'm invoking the showSaveDialog method with a file filter on .txt files.
Here is the problem:

If I call the file in the dialog with the name of "test", I wish it creates a "test.txt" file (I've set the FileFilter for this reason), but it creates a file without extension called "test".
What is the purpuose of the FileFilter in the SaveDialogs, then?

Thanks