Well, I couldn't find this post's title on google, so here it is.
Eclipse WST plugin stores java source which are generated from JSP files at this location under workspace:
.metadata/.plugins/org.eclipse.wst.server.core/tmp0/work/Catalina/localhost/<YOURAPPNAME>/org/apache/jsp
Well, what is this? As you probably know, all JSP files are converted to servlets at runtime. Normally you wouldn't need to look at this generated code, but as a JSP novice (like me) would understand some obscure errors somewhat more easily by looking at these sources.