When a release candidate has been cut, a vote is started, inviting all members of the community to test the release candidate before actually declaring it an official release. What/how to test before casting your vote?
Just download the distributables and check their contents:
Download and unpack the release candidate's source distribution. To test if all dependencies are available and all the necessary Maven repositories have been properly declared, it's best to temporarily move aside (or delete) your local Maven repo:
Afterwards, do a full build as usual, preferably including running all unit tests.
Download and unpack the binary distribution. Try running the examples.