EL in struts 2 not working

I have a search form(name = studentForm) that is submitted to struts2 action which fetches data from db and returns to a JSP with a form (name = studentListForm).

When I use s:property, I'm able to get a property from the action form, whereas with EL is empty.

Action

private int    pageNumber;
/** some code here **/
setPageNumber(1);
public int getPageNumber()
{
    return pageNumber;
}

public void setPageNumber(int pageNumber)
{
    this.pageNumber = pageNumber;
}

JSP

<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<%@ taglib prefix="s" uri="/struts-tags"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>    
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<s:form id="studentListForm" name="studentListForm" action="student.do" method="post" class="pure-form pure-form-aligned">
<table width="50%">

            <tr>
                <td align="center" colspan="2">
                    <!-- This works -->
                    <s:property value="pageNumber"/> 
                    <!-- This doesn't -->
                    <c:out value="${studentListForm.pageNumber}"></c:out>
                </td>
            </tr>
</table>
<div id="hiddenFields">
  <s:hidden key="pageNumber"></s:hidden>
</div>
</s:form>
</html>

Solution

You need to change EL to find your action variable in the valueStack.

<c:out value="${pageNumber}"/>

Note, that EL expressions should have access to valueStack variables due to Struts request wrapper. See How we use JSTL with the framework.