I was having problems with this and then discovered that with the version of Tomcat that I am using ( 5.0 ), the commons/lib directory does contain the servlet-api.jar, however, when I opened it to check if it contained the jsp directory, it did not. I then found jsp-api.jar in the same directory and I believe this is the archive that contains the required files.
Hope this helps!
Have a good one.
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-Oak McIlwain-
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