clarify Java requirements


git-svn-id: https://svn.apache.org/repos/asf/continuum/trunk@1532164 13f79535-47bb-0310-9956-ffa450edef68
use released plugin


git-svn-id: https://svn.apache.org/repos/asf/continuum/trunk@1532165 13f79535-47bb-0310-9956-ffa450edef68