Can a Java Applicaton and a JavaScript running in a browser communicate with each other?

Question

I have a JavaScript embedded in a website, running in a normal browser, and I have a Java Application running on the same machine. I am looking for a way have both communicate with each other.

I assume that creating files in the local file system from inside JavaScript running in a browser is out of question.

The only way I came up with would be to use a server that both programs can send messages to, and from which they poll for new messages.

Is there any other other way to accomplish this?

Answer 1

A couple of ways I saw in practice:

• You Java Application may listen to some local port which your JS will access for instance via XHR. You'll need to mind cross-site scripting (your JS may need to be loaded from that local URL), but this is doable. The easiest would probably be to run an embedded HTTP server.
• Your Java Application may be registered as a protocoll handler in the OS. Then JS would open links registered with the application thus sending data to it.

As @PavelHoral is pointing out, CORS is a way to workaround same-origin policy.