Bad, bad, bad. Never copy anything to the lib/ext directory of the jre. Learn how to use and set classpaths properly. If he has the proper jarfile, and places it in the WEB-INF/lib directory of the web application he is trying to reach, the classes will be found. If they are not, he has done something wrong. Either copied it to the lib directory of the wrong application, not copied the right jarfile, or, maybe, somehow or another, changed the tomcat configuration so that it does not look there. Sorry to say it, but all of those things are "his problem", and copying anything to the lib/ext directory is not the answer, regardless of whether or not "it works".