Associate file type with Java Swing application

I am creating a java swing application and I need to set the my program as the default program for the file extension .mcsd (MIME type text/mcsd). This must work on windows, and it would be nice if it worked on OS X/Linux as well. I am somewhat new to java (3 or 4 months) so please don't bombard me with all kinds of expert talk.

I have seen associating a custom file extension with java app in windows, but I would prefer not to use the Java Web Start. If possible, I would also like to know how to set the icon of that file type. I have found exe4j as a way of creating the .exe and plan to use it, but if is not the best tool for convertinf to an exe or someone knows something better feel free to tell me. Another thing: I need to be able to get the data from this file after the program has opened.

So my question is: how do I do this?

Deploy the app. with Java Web Start:

JWS provides many appealing features including, but not limited to, splash screens, desktop integration, file associations, automatic update ..

See the file services demo. for an example of a JNLP that declares an interest in the .zzz file type.

This is how the association is declared in the JNLP:

<association
  extensions="zzz"
  mime-type="text/sleepytime" />

JWS is supplied by Oracle and works on Windows, *nix & OS X.

..but I would prefer not to use the Java Web Start. Because I would like to have a native installer that just installs the program, without opening a web page or anything. If that's not how (web start) works, then I'm happy to use it.

JWS works over the web or a network. But if you can invoke the opening of an URL (to the JNLP) from the desktop, there does not need to be any browser opened.

Would I do that using openConnection() on a URL object?

I would use the Desktop or BasicService API.

Desktop.getDesktop().browse(uri);

boolean result = basicService.showDocument(url);

As noted in the BasicService demo.

In Java 6+, a call to show another web start launch file (e.g. BasicService.showDocument(another.jnlp)) will be handed directly to JavaWS, with no browser window appearing.

I expect this has always been true of the Desktop API, given the JWS client is the default consumer for that file type.