Problem Retrieving Session Attributes
Hi,
I have a web application where the user hits a servlet which does some processing and puts attributes into the session and then forwards the request on to a JSP. The JSP then retrieves the attributes from the session.
I can retrieve session attributes using EL but not scriptlets. For example, the the string is proprerly retrieved/displayed for this:
<c:out value="${sessionScope.TEXT_ACTIVE}" />
but not for:
<%
Integer maxItems =new Integer((String)session.getAttribute("itemsPerPage"));
int maxPageItems = maxItems.intValue();
%>
I get a NumberFormatException because the attribute retrieved is null. I've confirmed in my servlet code that the attribute is set before I do the forward.
I've used scriptlets to retrieve session attributes before, and I'm not doing anything differently (I think). As far as I know, it should "just work". Does anyone have any thoughts on what might be wrong?
All help appreciated.
[1125 byte] By [
ShelliOa] at [2007-11-26 14:59:08]
# 1
Usually it is mis-naming error, spelling or capitalization error between the attribute name added to the session and the attribute name retrieved from the session.
Another possiblility is that you are putting a null value in the session or after setting the session attribute you are nulling the object.
As a side note what is wrong with using the Integer.parseInt(String) method to convert a string to an int. It eliminates the need to create an Integer object.
# 2
It should work even if you try to set the session value with c:set and try to retrieve it with session.getAttribute.
Here's a small example of what I tried and it worked:
index.jsp
~~~~~~~
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
<html>
<head><title></title></head>
<body>
<%
session.setAttribute("firstAttribute","firstValue");
%>
<c:set var="secondAttribute" value="secondValue" scope="session"/>
</body>
</html>
page2.jsp
~~~~~~~~
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head><title></title></head>
<body>
<%=session.getAttribute("firstAttribute")%>
<%=session.getAttribute("secondAttribute")%>
</body>
</html>
