Why the JSP pages under WEB-INF can't be accessible with sendRedirect method?

Question

Those pages under WEB-INF are accessible using forward method of RequestDispatcher. Whats wrong with sendRedirect?

Answer 1

The pages under WEB-INF are not accessible from outside the web application.

Now, since using HttpServletResponse#sendRedirect(), a new request is created by client, so the request is actually sent from the browser, and therefore you cannot have WEB-INF in path to sendRedirect.

In case of RequestDispatcher, the methods - forward() and include(), doesn't ask the client to create a new request, rather they use the same request to forward to/include a different page from most probably the Servlet Controller. That is why you can give path to a file under WEB-INF, as you are accessing it from inside the web application only.