JFileChooser - multiple file filters?

use

filter.addChoosableFileFilter(new FileNameExtensionFilter(description, extensions));

as many as the number of your extensions.

I think you want the addChoosableFileFilter method. Read the tutorial.

You can simply create a filter that subclasses FileFilter and call the method I outlined above with that filter as an argument.

I'm sure you have already solved this to your satisfaction, but I came across this link at the same time I came across your question. In particular, look at section 3 for a way to generate multiple filters easily.