javax.servlet.ServletException: java.lang.NoClassDefFoundError: javelin/jsp/JspFunctionMapper

Recently I come across above error on weblogic 12c migration project, since  for my test I used fexisting old ear that was built for weblogic 10.0.2 version. Later I found that this error has caused a problem because application is using pre-compiled jsps inside, I also noticed that weblogic 10.3.0  this jsp compilation has been depricated. so the solution was to remove the pre-compiled jsp classes from your war file or compile them again using weblogic 12c, I took a shortcut to remove classes and guess what, it failed again, since you must also know that who wants to use pre-complied jsps also use JSPClassServlet servlet to make sure that
weblogic at runtime should not try to recompile them and must always use pre-compiled. So that was additional task for me to remove this servlet and its mapping from web-inf to make sure my shortcut way should work.