I was reading page 461 of HeadFirstSJ, where it is written in handwriting,
Note: the exception implicit object is available ONLY to error pages with an explicitly-defined page directive. <%@page isErrorPage="true"%>
In other words, configuring an error page in the DD is not enough to make the Container give that page the implicit exception object!
My confusion: I am using apache-tomcat-5.5.23. I configured error page in the Deployment Descriptor. But I didn't explicitly define the <%@page isErrorPage="true"%> in my errorPage.jsp and it is still working. Is it something container specific?