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changes.mady.by.user Hernan Cunico

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changes.mady.by.user Ashish Jain

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Comment: Migration of unmigrated content due to installation of a new plugin

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  1. Right click on WebJMS project and create a new servlet.





  2. Name the servlet as UserServlet and package as webjms. This is the producer in the application.





  3. Select Next and later Finish.





  4. Add the following code to UserServlet.java
    Code Block
    titleUserServlet.java
    borderStylesolid
    package webjms;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Enumeration;

import javax.annotation.Resource;
import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class for Servlet: UserServlet
 *
 */
 public class UserServlet extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet {
	 @Resource(name="jms/TestConnectionFactory")
	 private ConnectionFactory connectionFactory;
	 @Resource(name="jms/TestQueue")
	 private Queue queue;
	 static final long serialVersionUID = 1L;
   
   
    /* (non-Java-doc)
	 * @see javax.servlet.http.HttpServlet#HttpServlet()
	 */
	public UserServlet() {
		super();
	}   	
	
	/* (non-Java-doc)
	 * @see javax.servlet.http.HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		PrintWriter out = response.getWriter();
		if(connectionFactory == null) {
			out.println("Connection Factory lookup has failed");
			return;
		}
		
		if(queue == null) {
			out.println("Queue lookup has failed");
			return;
		}
		
		
		
		Connection connection = null;
		try {
			connection = connectionFactory.createConnection();
			connection.start();
			Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
			MessageProducer producer = session.createProducer(queue);
			TextMessage message = session.createTextMessage();
			Enumeration arr=request.getParameterNames();
			while(arr.hasMoreElements())
			{
				String fields= (String)arr.nextElement();
				String paramname[]=request.getParameterValues(fields);
				for (int i=0; i<paramname.length;i++)
				{	
				String s=null;
				s=fields+":" + paramname[i];
				message.setText(s);
				producer.send(message);
				}
				
			}
			out.println("Your request has been sent to administrator.");
            //Send a non-text control message indicating end of messages.
            producer.send(session.createMessage());
		} catch (JMSException e) {
			e.printStackTrace();
		} finally {
			if(connection != null) {
				try {
					connection.close();
				} catch (JMSException e1) { }
			}
		}
	}
	
	/* (non-Java-doc)
	 * @see javax.servlet.http.HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}   	  	    
}

    Lets try to understand the code
    • @Resource(name="jms/TestConnectionFactory")- This is a resource injection wherein connection factory has been injected.
    • @Resource(name="jms/TestQueue")- a queue previously created has been injected. Resource injection is useful in the sense that we need not include the entries in a deployment descriptor.
    • Servlets follow a request response model wherein a request is send to servlet and a response is generated. The function protected void doGet(....,....) follows a request response model.
    • PrintWriter out = response.getWriter()- This statement returns a PrintWriter object which is used to send HTML content to client page.
    • connection = connectionFactory.createConnection()- Creates a connection to jms/TestConnectionFactory
    • Session session = connection.createSession(..,..)- A session is a context for producing and consuming messages. Use this statement we create a new session.
    • MessageProducer producer = session.createProducer(queue)- A client uses message producer to send messages to a destination. Queue name is passed to createProducer method provided by session object.
    • TextMessage message = session.createTextMessage()- A TextMessage is used to send a message of java.lang.String type.
  5. Similarly create a second servlet AdminServlet. This is the consumer in the application.


    Image Added


    Image Added


    Add the following code to AdminServlet.java
    Code Block
    titleAdminServlet.java
    Similarly create a second servlet AdminServlet. This is the consumer in the application.
    Image Removed
    Image Removed
    Add the following code to AdminServlet.java
    Code Block
    titleAdminServlet.java
    borderStylesolid
    package webjms;

import java.io.IOException;
import java.io.PrintWriter;

import javax.annotation.Resource;
import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class for Servlet: AdminServlet
 *
 */
 public class AdminServlet extends javax.servlet.http.HttpServlet implements javax.servlet.Servlet {
	 @Resource(name="jms/TestConnectionFactory")
		private ConnectionFactory connectionFactory; 
		
		@Resource(name="jms/TestQueue")
		private Queue queue;
		
		/* (non-Java-doc)
		 * @see javax.servlet.http.HttpServlet#HttpServlet()
		 */
		public AdminServlet() {
			super();
		}   	
		
		/* (non-Java-doc)
		 * @see javax.servlet.http.HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
		 */
		protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
			PrintWriter out = response.getWriter();
			if(connectionFactory == null) {
				out.println("Connection Factory lookup has failed");
				return;
			}
			if(queue == null) {
				out.println("Queue lookup has failed");
				return;
			}
			Connection connection = null;
			try {
				connection = connectionFactory.createConnection();
				Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
				MessageConsumer consumer = session.createConsumer(queue);
				connection.start();
				out.println("The following information has been received for updation\n");
				while(true) {
					Message m = consumer.receive(); 
					if (m instanceof TextMessage) {
						TextMessage message = (TextMessage) m;
						out.println(message.getText());
					} else {
						break;
					} 
				}
			} catch (JMSException e) {
				e.printStackTrace();
			} finally {
				if(connection != null) {
					try {
						connection.close();
					} catch (JMSException e1) { }
				}
			}
		}  	
		
		/* (non-Java-doc)
		 * @see javax.servlet.http.HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
		 */
		protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
			doGet(request, response);
		}   	  	    
	}
  6. Right Click on WebContent and create a jsp.





  7. Name the jsp as index.jsp. Select Next.





  8. Select Finish.





    Add the following code to index.jsp
    Code Block
    titleindex.jsp
    borderStylesolid
    <%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Sample Web Application accessing JMS Resources</title>
</head>
<body>
<form action="/WebJMS/UserServlet">
<h1>Please enter the updated information</h1>
<table>
<tr>
<td>UserName:</td>
<td><input type="text" name="username" size="30"></td>
</tr>
<tr>
<td>UserID:</td>
<td><input type="text" name="userid" size="30"></td>
</tr>
<tr>
<td>Old Address:</td>
<td><input type="text" name="oldaddress" size="30"></td>
</tr>
<tr>
<td>New Address:</td>
<td><input type="text" name="newaddress" size="30"></td>
<tr>
</table>
<input type="submit" value="Submit">
</form>
</body>
</html>
    This will create the producer, consumer and user interface required by the application.

...

Code Block
titlegeronimo-web.xml
borderStylesolid
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://geronimo.apache.org/xml/ns/j2ee/web-1.2" 
         xmlns:nam="http://geronimo.apache.org/xml/ns/naming-1.2" 
         xmlns:sec="http://geronimo.apache.org/xml/ns/security-1.1" 
         xmlns:sys="http://geronimo.apache.org/xml/ns/deployment-1.2">
  <sys:environment>
    <sys:moduleId>
      <sys:groupId>default</sys:groupId>
      <sys:artifactId>WebJMS</sys:artifactId>
      <sys:version>1.0</sys:version>
      <sys:type>car</sys:type>
    </sys:moduleId>
    <sys:dependencies>
            <sys:dependency>
                <sys:groupId>org.apache.geronimo.configs</sys:groupId>
                <sys:artifactId>activemq-ra</sys:artifactId>
                <sys:version>2.1</sys:version>
                <sys:type>car</sys:type>
            </sys:dependency>
        </sys:dependencies>
  </sys:environment>
  <context-root>/WebJMS</context-root>
  <nam:resource-ref>
        <nam:ref-name>jms/TestConnectionFactory</nam:ref-name>
        <nam:pattern>
            <nam:groupId>org.apache.geronimo.configs</nam:groupId>
            <nam:artifactId>activemq-ra</nam:artifactId>
            <nam:version>2.1</nam:version>
            <nam:name>DefaultActiveMQConnectionFactory</nam:name>
        </nam:pattern>
    </nam:resource-ref>
    <nam:resource-env-ref>
        <nam:ref-name>jms/TestQueue</nam:ref-name>
        <nam:pattern>
            <nam:groupId>org.apache.geronimo.configs</nam:groupId>
            <nam:artifactId>activemq-ra</nam:artifactId>
            <nam:version>2.1</nam:version>
            <nam:name>SendReceiveQueue</nam:name>
        </nam:pattern>
    <nam:artifactId>activemq-ra</nam:artifactId>
            <nam:version>2.1</nam:version>
            <nam:name>SendReceiveQueue</nam:name>
        </nam:pattern>
    </nam:resource-env-ref>
</web-app>
</nam:resource-env-ref>
</web-app>

The deployment plan has been modified to include active-mq dependencies and resource references for queue(TestQueue) and Connection Factory(Test Connection Factory).
<sys:dependency>- Defines the dependency of the application on ActiveMQ
<nam:resource-ref>- This tag is basically used to define connections that can be JDBC Connection, Java Mail connection or JMS Connection Factory. In our case we are using it for JMS Connection Factory.
<nam:resource-env-ref>- This tag is basically used to define a resource. In our case we have defind the message destination that is the TestQueue.

Deploy and Run

Warning
titleWarning

Due to some limitation with GEP you need to export the project. This issue will be fixed soon.

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