CODEWITHSUNDEEP
model-view-controllerjspservlets
ConditionRacer
ConditionRacer

Reputation: 4498

Servlet to jsp communication best practice

I'm learning how to write java servlets and jsp pages on google app engine. I'm attempting to use an MVC model but I'm not sure if I'm doing it right. Currently, I have a servlet that is called when a page is accessed. The servlet does all the processing and creates a HomePageViewModel object that is forwarded to the jsp like this:

// Do processing here
// ...
HomePageViewModel viewModel = new HomePageViewModel();
req.setAttribute("viewModel", viewModel);

//Servlet JSP communication
RequestDispatcher reqDispatcher = getServletConfig().getServletContext().getRequestDispatcher("/jsp/home.jsp");
reqDispatcher.forward(req, resp);

Over on the jsp side, I have something like this:

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ page import="viewmodels.HomePageViewModel" %>
<%
  HomePageViewModel viewModel = (HomePageViewModel) request.getAttribute("viewModel");
  pageContext.setAttribute("viewModel", viewModel);
%>

<html>
  <body>
  <% out.println(((HomePageViewModel)pageContext.getAttribute("viewModel")).Test); %>
  </body>
</html>

So my question is two fold. First, is this a reasonable way to do things for a small webapp? This is just a small project for a class I'm taking. And second, in the jsp file, is there a better way to access the viewmodel data?

Upvotes: 4

Views: 2956

Answers (1)

BalusC
BalusC

Reputation: 1108557

If you adhere the Javabeans spec (i.e. use private properties with public getters/setters), 

public class HomePageViewModel {

    private String test;

    public String getTest() { 
        return test;
    }

    public void setTest(String test) {
        this.test = test;
    }

}

then you can just use EL (Expression Language) to access the data.

<%@ page pageEncoding="UTF-8" %>
<html>
  <body>
  ${viewModel.test}
  </body>
</html>

See also:

Upvotes: 7

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