Add counters.

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1485220 13f79535-47bb-0310-9956-ffa450edef68
Restructure to catch exceptions systematically.

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1485221 13f79535-47bb-0310-9956-ffa450edef68