Servlet not forwarding attributes to JSP (JSP receives null)

Question

Servlet

    ArrayList<String[]> itemsInCart = new ArrayList<String[]>();
    String[] test = {"bah","3.50","false"};
    itemsInCart.add(test);

    ArrayList<Integer> testALEmpty = new ArrayList<>();
    ArrayList<Integer> testALItems = new ArrayList<>();
    testALItems.add(1);
    testALItems.add(2);
    testALItems.add(3);


    String testStr = "This is a test string";

    request.setAttribute("testALEmpty", testALEmpty);
    request.setAttribute("testALItems", testALItems);

    request.setAttribute("testStr", testStr);

    request.setAttribute("cartAttribute", itemsInCart);


    try {
        getServletContext().getRequestDispatcher("/Cart.jsp").forward(request, response);
    } catch (Exception e) {
        e.printStackTrace();
    }

JSP

if (request.getAttribute("cartAttribute") == null) {
%>
<b>No Cart</b>
<%
}

When the servlet forwards to the JSP, I have No Cart because for some reason the servlet is not passing the attributes to the JSP.

Answer 1

set request attribute to session attribute:

request.getSession().setAttribute("parameter", "test");

or

There are two ways you can accomplish this.

Using a JSP expression you would use <%= %> as (notice no ; at the end)

<%= parameter %>

The second and preferred way is to use JSP EL syntax and reference the request attribute directly using ${ } as

${parameter}

The first option requires you to pull the attribute out of its scope first. The second doesn't.

String parameter = (String) request.getAttribute("parameter");