generify cache service

git-svn-id: https://svn.apache.org/repos/asf/archiva/redback/redback-components/trunk@1429391 13f79535-47bb-0310-9956-ffa450edef68
generics for test

git-svn-id: https://svn.apache.org/repos/asf/archiva/redback/redback-components/trunk@1429392 13f79535-47bb-0310-9956-ffa450edef68