Expression Language Example : 1

Posted on by hrthaker

In this example servlet stores data using request, session and application object and passes to jsp page jsp page retrieves data using Expression Language

c:\tomcat\webapps\ELDemo\WEB-INF\classes\test\ScopedVars.java

package test;

import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;

public class ScopedVars extends HttpServlet
{
	public void doGet(HttpServletRequest req,HttpServletResponse res) throws IOException,ServletException
	{
		req.setAttribute("Attb1","Request attribute value");

		HttpSession session = req.getSession();
		session.setAttribute("Attb2","Session attribute value");

		ServletContext application = getServletContext();
		application.setAttribute("Attb3","Application attribute value");

		application.setAttribute("Attb4","Application New Value");
		session.setAttribute("Attb4","Session New Value");
/*		req.setAttribute("Attb4","Request New Value");*/

		RequestDispatcher rd = req.getRequestDispatcher("ScopedVars.jsp");
		rd.forward(req,res);
         }
}

Accessing Data stored in servlet in JSP Page using EL

c:\tomcat\webapps\ELDemo\ScopedVars.jsp

${Attb1}

${Attb2}

${Attb3}

${Attb4}

c:\tomcat\webapps\ELDemo\WEB-INF\web.xml

<?xml version="1.0" encoding="ISO-8859-1"?>
<!--
  Licensed to the Apache Software Foundation (ASF) under one or more
  contributor license agreements.  See the NOTICE file distributed with
  this work for additional information regarding copyright ownership.
  The ASF licenses this file to You under the Apache License, Version 2.0
  (the "License"); you may not use this file except in compliance with
  the License.  You may obtain a copy of the License at

      http://www.apache.org/licenses/LICENSE-2.0

  Unless required by applicable law or agreed to in writing, software
  distributed under the License is distributed on an "AS IS" BASIS,
  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  See the License for the specific language governing permissions and
  limitations under the License.
-->
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
                      http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
  version="3.0"
  metadata-complete="true">

    <description>
      Servlet and JSP Examples.
    </description>
    <display-name>Servlet and JSP Examples</display-name>
	<servlet>
		<servlet-name>CollectionDemo</servlet-name>
		<servlet-class>collection.CollectionDemo</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>CollectionDemo</servlet-name>
		<url-pattern>/CollectionDemo</url-pattern>
	</servlet-mapping>

</web-app>