JBridge: Certification Question Of The Day

Assume there is an error page set up in the deployment descriptor for error code 500. What true statements can then be made regarding the following servlet code?

protected void doGet(HttpServletRequest request, HttpServletResponse response)
		throws ServletException, IOException {
  PrintWriter out = response.getWriter();
  out.write("Your error is about to be generated");
  response.setStatus(HttpServletResponse.SC_INTERNAL_SERVER_ERROR);
}

The Answer

A and C are the correct answers. It is inappropriate to use an error code (in the 400 and 500 series) with the setStatus method, which should be reserved for non-error outcomes (e.g. SC_OK or SC_MOVED_TEMPORARILY). Nonetheless, since the status SC_INTERNAL_SERVER_ERROR is set - which is status code 500 - this matches the error page set up, and so the error page is displayed. (I have tested this against the Tomcat standalone container, which is the reference implementation - it MAY be servlet container dependent. If you can clarify this, please email me).
Since the error page is displayed, the words "Your error is about to be generated" are not output, so answer B is wrong.
The servlet compiles just fine, ruling out answer D.
And SC_INTERNAL_SERVER_ERROR is a static int data member of HttpServletResponse, with a value of 500 - which does correspond with the error code set up for the error page in the deployment descriptor. So answer E is wrong.