Android also has decent command line tool support and a build system based on Ant. I'm not a huge fan of ant, but the default setup works all right and is extensible. I've mostly managed to stay inside Emacs for Android development.

there is an official gradle support (still a work in progress): http://tools.android.com/tech-docs/new-build-system/user-gui... .

In all sincerity please dont refer to Java and Android in the same sentence.

As far as Google is concerned, Java does not run on Android and you might be bearing witness to something that Google disclaims.

Yes indeed. http://developer.android.com/sdk/installing/studio.html