MQSeries.net :: View topic - Stateless Session Bean - Receiver

cactus · Posted: Tue Nov 04, 2008 4:24 pm Post subject:

As per application requirement we want to create stateless session bean instead of MDB.

When I invoke receiveMessage() method using Universal Test Client in RSA,it throws java.lang.NullPointerException when it is reading messages from the queue.(message = consumer.receive(10000);)

Below is the bean code and deployment descriptor.

package ejbs;

import java.util.logging.Level;
import java.util.logging.Logger;

import javax.ejb.CreateException;
import javax.ejb.SessionBean;
import javax.ejb.SessionContext;
import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MessageConsumer;
import javax.jms.Message;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.naming.InitialContext;
import javax.naming.NamingException;

/**
* Bean implementation class for Enterprise Bean: ReceiveMsgBean
*/
public class ReceiveMsgBeanBean implements javax.ejb.SessionBean {

static final long serialVersionUID = 3206093459760846163L;
public static final String CONN_FACT_NAME = "java:comp/env/jms/JMSExampleConnectionFactoryRef";
public static final String QUEUE_NAME = "java:comp/env/jms/JMSExampleQueueRef";

public void receiveMessage() throws NamingException, JMSException{
consumeMessage(CONN_FACT_NAME, QUEUE_NAME);
}

private void consumeMessage(String connectionFactoryJNDIName, String destinationJNDIName)
throws NamingException, JMSException{

Connection connection = null;
Session session = null;
MessageConsumer consumer = null;
Message message =null;

try {
InitialContext context = new InitialContext();
ConnectionFactory factory = (ConnectionFactory) context.lookup(connectionFactoryJNDIName);
Destination dest = (Destination) context.lookup(destinationJNDIName);
System.out.println("destinationJNDIName = "+destinationJNDIName.toString()+", dest = "+dest.toString());
connection = factory.createConnection();
session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
consumer = session.createConsumer(dest);
do{
System.out.println("Inside do loop : " );
System.out.println("Consumer = "+consumer.toString());
message = consumer.receive(10000);
System.out.println("Before converting message: " +message.toString());
TextMessage textMessage = (TextMessage)message;
System.out.println("after converting to textMessage: " +textMessage.toString());
String text = textMessage.getText();
System.out.println("Received : " + text);
}
while(message != null);
}//try
catch (NamingException e) {
mySessionCtx.setRollbackOnly();
throw e;
}
catch (JMSException e) {
mySessionCtx.setRollbackOnly();
Exception linked = e.getLinkedException();
System.out.println("Linked Exception " +linked);
mySessionCtx.setRollbackOnly();
throw e;
}
catch(Exception e ){
e.printStackTrace();
System.out.println("Failed to get connection...exception is " +e);
}
finally {
consumer.close();
session.close();
connection.close();
System.out.println("******* Finally closed all connections ********");
}
}//consumeMessage
private javax.ejb.SessionContext mySessionCtx;
/**
* getSessionContext
*/
public javax.ejb.SessionContext getSessionContext() {
return mySessionCtx;
}
/**
* setSessionContext
*/
public void setSessionContext(javax.ejb.SessionContext ctx) {
mySessionCtx = ctx;
}
/**
* ejbCreate
*/
public void ejbCreate() throws javax.ejb.CreateException {
}
/**
* ejbActivate
*/
public void ejbActivate() {
}
/**
* ejbPassivate
*/
public void ejbPassivate() {
}
/**
* ejbRemove
*/
public void ejbRemove() {
}
}

<?xml version="1.0" encoding="UTF-8"?>
<ejb-jar id="ejb-jar_ID" version="2.1" xmlns="http://java.sun.com/xml/ns/j2ee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee http://java.sun.com/xml/ns/j2ee/ejb-jar_2_1.xsd">
<display-name>
LTCJMSWMQBeans</display-name>
<enterprise-beans>
<session id="SendMsgBean">
<ejb-name>SendMsgBean</ejb-name>
<local-home>ejbs.SendMsgBeanLocalHome</local-home>
<local>ejbs.SendMsgBeanLocal</local>
<ejb-class>ejbs.SendMsgBeanBean</ejb-class>
<session-type>Stateless</session-type>
<transaction-type>Container</transaction-type>
<resource-ref id="ResourceRef_1225757582149">
<description>
</description>
<res-ref-name>jms/JMSExampleConnectionFactoryRef</res-ref-name>
<res-type>javax.jms.ConnectionFactory</res-type>
<res-auth>Container</res-auth>
<res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>
<message-destination-ref id="MessageDestinationRef_1225757673274">
<description>
</description>
<message-destination-ref-name>jms/JMSExampleQueueRef</message-destination-ref-name>
<message-destination-type>javax.jms.Destination</message-destination-type>
<message-destination-usage>ConsumesProduces</message-destination-usage>
<message-destination-link>JMSExampleQueue</message-destination-link>
</message-destination-ref>
</session>
<session id="ReceiveMsgBean">
<ejb-name>ReceiveMsgBean</ejb-name>
<local-home>ejbs.ReceiveMsgBeanLocalHome</local-home>
<local>ejbs.ReceiveMsgBeanLocal</local>
<ejb-class>ejbs.ReceiveMsgBeanBean</ejb-class>
<session-type>Stateless</session-type>
<transaction-type>Container</transaction-type>
<resource-ref id="ResourceRef_1225814890501">
<description>
</description>
<res-ref-name>jms/JMSExampleConnectionFactoryRef</res-ref-name>
<res-type>javax.jms.ConnectionFactory</res-type>
<res-auth>Container</res-auth>
<res-sharing-scope>Shareable</res-sharing-scope>
</resource-ref>
<message-destination-ref id="MessageDestinationRef_1225814890501">
<description>
</description>
<message-destination-ref-name>jms/JMSExampleQueueRef</message-destination-ref-name>
<message-destination-type>javax.jms.Destination</message-destination-type>
<message-destination-usage>Consumes</message-destination-usage>
<message-destination-link>JMSExampleQueue</message-destination-link>
</message-destination-ref>
</session>
</enterprise-beans>
<assembly-descriptor id="AssemblyDescriptor_1225758252768">
<message-destination>
<description>
</description>
<message-destination-name>JMSExampleQueue</message-destination-name>
</message-destination>
</assembly-descriptor>
</ejb-jar>

Pls let me know,if there is any problem in the code/XML.

thankx
_________________
thankx
cactus