Struts 2 Memory leaks

Has anyone experienced that Struts 2 is heavy on the JVM Memory on the server? As an example, maybe some people have noticed, when I do some practice things with struts, and deploy small app onto Tomcat, sometimes I see logs on tomcat saying that

Application might have created memory leak, and should be removed manually...

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or something similar.

Also, running my project on WebLogic, I start to experience delays in WL responses, unlike to anything I saw before I deployed Struts 2 app on it. It is a general question. Any comments are appreciated.