Installed manually, since the aur version did not work.
Installation instructions
Dependencies: apache-ant groovy python2-sphinx python2-docutils
(Those dependencies were not installed before. For full dependency list see PKGBUILD of eclim in the aur)
To properly install the vim plugin so that vim recognizes it, move the eclim folder out of .vim/bundle/ and into .vim/pack/vendor/start/. This will start the plugin automatically on startup.
First run eclimd, the eclim daemon. It is located in your $ECLIPSE_HOME (by default in ~/.eclipse/<eclipse_version>). To run it, just execute ./eclimd. It might be worth to symlink this to ~/.local/bin.
Once the eclim daemon is started, vim should be able to talk to the server. Ping the server via :PingEclim. If eclim is running and vim can talk to it, it should print the eclim and eclipse version you have installed.
:ProjectImport <path_to_project_root>ProjectOpen <project_name>Ctrl-X Ctrl-U:Java:ProjectNew <type> package.name:JavaImportOrganize