How can I pass information from a servlet to JSP and back?

Question

I've been scratching my head for hours now. I'm working expanding a web app and I've come across this problem:

I have a class called SelectionHandler which uses cases in a doPost() method to forward to the right app:

private void userEditor(HttpServletRequest request, HttpServletResponse response) {
response.setHeader("destination", "edit_user");
    HttpRedirectHandler.forwardToURL(request, response, "EditUser");
}

Now this servlet is designed to be re-used, so it will decide where to forward the user next:

String header = response.getHeader("destination");
if (header.equals("price_manager")) {
    destination = "PriceManager";
} else if (header.equals("new_user")){
    destination = "NewUser";
};

and then

HttpRedirectHandler.forwardToURL(request, response, destination);

But before that happens I've been redirecting the user to a JSP page. Problem is, when I do that the information where I wanted to go gets lost.
Can someone advise me as to what is the best way to retain this information? I tried reading the header and writing it again to a header in the JSP page, but I'm not sure that is actually possible.

Answer 1

example:

In your servlet:

request.setAttribute("HelloKey","Hello World!");

In your jsp:

String myHelloString = (String)request.getAttribute("HelloKey");

or you put it in the session:

request.getSession(true).setAttribute("HelloKey","Hello World!");

and in the jsp:

String myHelloString = (String)request.getSession().getAttribute("HelloKey");

Answer 2

I agree with the previous post, you can store information in request, session, or application scope.

I would like to expand on the answer as follows: From your statement about "I tried reading the header and writing it again to a header in the JSP page", it appears you may not have enough of a grasp on JSP. I suggest you go to amazon.com and look for a JSP book that has good reviews. Then, read it cover to cover. It will save you countless hours of experimenting with the technology and not getting anywhere.