How can I set a session variable in a servlet and get it in a JSP?

Question

I\'m learning java and try to pass some variable from servlet to jsp page. Here is code from servlet page

@WebServlet(\"/Welcome\")
public class WelcomeServl         


        

Answer 1

you are getting if from request not session.

It should be

session.getAttribute("MyAttribute")

---

I suggest you to use JavaServer Pages Standard Tag Library or Expression Language instead of Scriplet that is more easy to use and less error prone.

${sessionScope.MyAttribute}

or

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>

<c:out value="${sessionScope.MyAttribute}" />

you can try ${MyAttribute}, ${sessionScope['MyAttribute']} as well.

Read more

• Oracle Tutorial - Using JSTL

• Oracle Tutorial - Expression Language

Answer 2

You set an attribute in a session. You have to retrieve it from a session:

Object sss = session.getAttribute("MyAttribute");

And since you are dispatching the request, you actually don't need a session. You can set the attribute in a request object in your servlet:

request.setAttribute("MyAttribute", "test value");

Then read it as you are already doing in you JSP.

Answer 3

You should avoid scriptlets because they are java code in HTML, they break MVC pattern, they are ugly, odd and deprecated.

Simply replace :

<% 
Object sss = request.getAttribute("MyAttribute"); 
String a = "22";

%>

with simply using EL ${MyAttribute}

But if you want to stick with scriptlets, you should get the attribute from the proper scope which is session in your case.