I have been using HtmlUnit (the developers did a great job) as an headless browser for some of my previous applications but the javascript support isn't working for some website that my next application will be accessing.
I heard about QtWebKit binding for Python but my application will be in Java or is there a Java binding for WebKit or QtWebKit?
Does anyone know a good headless browser for Java with full javascript support?
Nathan Ridley's answer to another similar question is the most complete one I've found so far.
Anyway, if everything fails, you could use a Python or JS alternative, expose its funcionality as a webservice inside your server, and then your Java application could use the headless browser's funcionality through the webservice. It would be a pain to set up, but it may be a viable alternative if nothing else works as desired.
Also, there are some "non-headless" browser wrappers for Java; maybe it would be possible to build a testing solution around those, depending on the requirements.