Stackoverflow markup for javadoc

There appears to be a Markdown Doclet for Javadoc, which should do what you want.

It's made by StackOverflow-user Richard Nichols. He has written a blog post on it, which includes a screenshot, of some example input/output.

MarkdownDoclet is a bit outdated.

For Java 7, use https://github.com/Abnaxos/pegdown-doclet