I\'m trying to get autocomplete working in eclipse for scala development. I\'m trying to reference a java class from a Scala class, and the autocomplete feature never finds it.
The best place for questions like this is the Scala IDE user mailing list.
I had the same problem, and the solution was simple. Pick the menu option Scala -> Run Setup Diagnostics.
I clicked everything that was called "recommended", and autocomplete started working. I am pretty sure I had done this previously, but the settings might have gotten lost in an update.
That type of auto-completion is not yet supported by the Scala plug-in. You can get a similar result by waiting for the compile error to appear, pressing Ctrl-1, and selecting the quick fix to automatically import the type.
See the "Quick fix imports" section in this "New and noteworthy" post.
Update September 2011:
Luc Bourlier has committed an improvement for this to give autocompletion for types on the classpath. It will be in the next beta (2.0.0-beta11), or grab a nightly build.
here is a simple workaround: https://www.assembla.com/spaces/scala-ide/wiki/Known_Issues#no_completions_available