URLs and RequestDispatcher.forward()

[Joshua Smith]

Fellow Ranchers-

I have a question regarding URLs after using RequstDispatcher.forward().

I have an HTML form in a login.jsp file with an action of LoginServlet. The relevant snippet of code from the LoginServlet is below.

        // validate
        String username = request.getParameter("username");
        String password = request.getParameter("password");

        //success
        if ((username.equals("foo")) && (password.equals("bar"))) {
            getServletContext().getRequestDispatcher("/success.jsp")
            .forward(request, response);

        // failed, login again
        } else {
            getServletContext().getRequestDispatcher("/login.jsp")
                     .forward(request, response);
        }
 

The URL before the login is: http://localhost:8080/SCWCD/login.jsp
The URL after a login (regardless of failure or success) is: http://localhost:8080/SCWCD/LoginServlet

Why doesn't the URL change to login.jsp or success.jsp? How can I make the URL change?

Thanks,
Josh

[Ankit Garg]

Since you are using RequestDispatcher, so the URL will not change. If you want to change the URL in the browser, then use response.sendRedirect()...

[Joshua Smith]

Thank you Ankit. Is there anything special about using response.sendRedirect() that I should be aware of? Is it the same a the RequestDispatcher except with the different URL or are there other things about it that I should be aware of?

Josh

[Ankit Garg]

When you use sendRedirect, then the browser sends a new request to the server. So like request dispatcher, you can't use request attributes. If you dispatch a request to a JSP, then the request attributes set by the servlet are maintained but with send redirect, any request attribute set by a servlet will not be maintained (this is logical as there is a new request so request attributes will be gone)...

[Bindu Lakhanpal]

You can also check the FAQredirect vs forward.

[Joshua Smith]

Thank you. That's very helpful. I think I'll write some code to verify to myself that I understand it.

Thanks!
Josh