JavaDoc in an Eclipse Android Project
If you have the "Documentation for Android" package and the javadoc info still isn't showing up, make sure the Android library settings point to the right folder:
Project -> Settings -> Java Build Path, Libraries tab
Android X.X -> Android.jar -> Javadoc Location:
Should be something like "sdk_root/docs/reference/".
And to view the docs for a class in editor for example:
you should choose show attached java doc in web browser from to popup that appear when hover the cursor on some declaration.
This answer is new and might not been available on 2010 when the question been askedAnd these docs include android SDK docs which many developers need and google app engine too