Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=57433 Use a ConcurrentMap for the cache. However, as our code always uses the same implementation, use a single instance of that and deprecate public access to the cache. Also includes some Java5 TLC.
tomcat/taglibs/standard/trunk/jstlel/src/main/java/org/apache/taglibs/standard/lang/jstl/Evaluator.java