Q: Is there a potential zip file classloading problem with Tomcat?

A: Yes, if you add a zip file in the WEB-INF/lib folder, Tomcat may not load this zip
   file into the classpath. The problem can be solved by renaming the zip extention to
   jar (you do not need unzip and jar the file, just need rename it).

   The above could cause problems if you use Oracle or DB2 databases since both their
   jdbc drivers are packaged into a zip file. If such a problem occurs, please rename
   classes12.zip to classes12.jar or db2java.zip to db2java.jar.