fbricon@redhat.com (from the comment in JBDS-3553):

If you want more than basic java/SWT recommendations, you can install the crowd-based recommendation database (aka Hippie) http://www.codetrails.com/crowd-recommendation-tools/getting-started
However, it uses a weird license (mostly because you can upload your own API usage stats), that probably requires to be vetted by a lawyer
It can be installed from the Eclipse Marketplace or via Preferences > Code Recommenders > Discover new extensions