Loop infinite urlPatterns

[Saulo Siqueira]

Hello, I'm studying Java EE and I am making an application to learn. I have the following problem.

Mapped a Servlet I'm calling him frontController. It receives all requests it is with the annotation @ WebServlet (urlpatterns = {"*. jsp"}).

Here is a code snippet below.

public void processRequest(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException, SQLException {

		displayPage = request.getParameter("display_page"); 
		action = request.getParameter("action");

		if(action == null) {
			action = "formGenerate";
		}
		
		if(displayPage == null) {
			displayPage = "home";
			request.setAttribute("display_page", "ticket");
		}
		
		if(displayPage.equals("home")) {
			HomeServlet homeServlet = new HomeServlet();
			homeServlet.formGenerate(request, response);
		}
		
		if(displayPage.equals("user")) {
			
			UserServlet userServlet = new UserServlet();
			
			if(action.equals("formGenerate")) {
				userServlet.formGenerate(request, response);
			}
			
			if(action.equals("alter")) {
				userServlet.alter(request, response);
			}
			
			if(action.equals("delete")) {
				userServlet.delete(request, response);
			}
		}

For it knows which servlet parameter should I call if for example I have the url as follows:

http://apli/index.jsp?display_page=user

Ira fall in if the above code snippet if (displayPage.equals ("user")) that will call the method below:

public void formGenerate(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException, SQLException {
		request.setAttribute("screenName", "Usuários");
		request.setAttribute("display_page", "user");
		datagrid(request, response);
		RequestDispatcher dispatcher = request.getRequestDispatcher("index.jsp");
		dispatcher.forward(request, response);
	}

At the end of the above method I run a dispatcher.forward (request, response) which is causing an infinite loop because it ends up going to frontController.

Who can help me?

thank you