Head First Servlets and JSP, 2nd Edition

Configuring error pages in the DD

You can declare error pages in the DD based on either the <exception-type> or the HTTP status <error-code> number. That way you can show the client different error pages specific to the type of the problem that generated the error.

Declaring a catch-all error page

This applies to everything in your web app—not just JSPs. You can override it in individual JSPs by adding a page directive with an errorPage attribute.

<error-page>
  <exception-type>java.lang.Throwable</exception-type>
  <location>/errorPage.jsp</location>
</error-page>

Declaring an error page for a more explicit exception

This configures an error page that’s called only when there’s an ArithmeticException. If you have both this declaration and the catch-all above, any exception other than ArithmeticException will still end up at the “errorPage.jsp”.

<error-page>
  <exception-type>java.lang.ArithmeticException</exception-type>
  <location>/arithmeticError.jsp</location>
</error-page>

Declaring an error page based on an HTTP status code

This configures an error page that’s called only when the status code for the response is “404” (file not found).