Util contains its own implementation of a URL encoder with a note to replace with the one from the JRE when minimum support level is Java 1.4 or later.
Created attachment 25718 [details] Patch to switch to using URLEncoder
svn ci -m "Upgraded to the JVM included version of URLEncoder from the Util.URLEncode method. Removing said method. Supplid by Jeremy Boynes to #49561" src/main/ Sending src/main/java/org/apache/taglibs/standard/tag/common/core/ParamSupport.java Sending src/main/java/org/apache/taglibs/standard/tag/common/core/Util.java Transmitting file data .. Committed revision 961057.