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Archive for July, 2015

JMS with Weblogic Server and EJB MDB

July 15th, 2015 Comments off

Here is a complete and short example of asynchronous development using JMS and a Message-Driven Bean (MDB).
First the procedure to configure inside Weblogic Server a JMS server in order to create a queue, then the code for the producer/sender of a message to the queue and then the code for a consumer (MDB).

1) Weblogic configuration
a) Create the JMS server

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b) Create a JMS module
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c) Create a destination (queue or topic)

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d) Create a connection factory

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2) Create a producer

For the producer, I got strongly inspired by the code found in this blog. This is a clean example of a producer/sender so no need to reinvent the wheel here.

import java.util.Hashtable;

import javax.jms.JMSException;
import javax.jms.Queue;
import javax.jms.QueueConnection;
import javax.jms.QueueConnectionFactory;
import javax.jms.QueueSender;
import javax.jms.QueueSession;
import javax.jms.TextMessage;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;

public class JMSProducer {

	private static InitialContext initialContext = null;
	private static QueueConnectionFactory queueConnectionFactory = null;
	private static QueueConnection queueConnection = null;
	private static QueueSession queueSession = null;
	private static Queue queue = null;
	private static QueueSender queueSender = null;
	private static TextMessage textMessage = null;
	private static final String CONNECTIONFACTORY_NAME = "ConnectionFactory-Test";
	private static final String QUEUE_NAME = "jms/QueueTest";

	public JMSProducer() {
		super();
	}

	public static void sendMessageToDestination(String messageText) {
		// create InitialContext
		Hashtable properties = new Hashtable();
		properties.put(Context.INITIAL_CONTEXT_FACTORY, "weblogic.jndi.WLInitialContextFactory");
		properties.put(Context.PROVIDER_URL, "t3://localhost:7001");
		properties.put(Context.SECURITY_PRINCIPAL, "weblogic");
		properties.put(Context.SECURITY_CREDENTIALS, "weblogic1");
		try {
			initialContext = new InitialContext(properties);
		} catch (NamingException ne) {
			ne.printStackTrace(System.err);
		}
		System.out.println("InitialContext : " + initialContext.toString());
		// create QueueConnectionFactory
		try {
			queueConnectionFactory = (QueueConnectionFactory) initialContext.lookup(CONNECTIONFACTORY_NAME);
		} catch (NamingException ne) {
			ne.printStackTrace(System.err);
		}

		System.out.println("QueueConnectionFactory : " + queueConnectionFactory.toString());
		// create QueueConnection
		try {
			queueConnection = queueConnectionFactory.createQueueConnection();
		} catch (JMSException jmse) {
			jmse.printStackTrace(System.err);
		}

		System.out.println("QueueConnection : " + queueConnection.toString());
		// create QueueSession
		try {
			queueSession = queueConnection.createQueueSession(false, 0);
		} catch (JMSException jmse) {
			jmse.printStackTrace(System.err);
		}

		System.out.println("QueueSession : " + queueSession.toString());
		// lookup Queue
		try {
			queue = (Queue) initialContext.lookup(QUEUE_NAME);
		} catch (NamingException ne) {
			ne.printStackTrace(System.err);
		}

		System.out.println("Queue : " + queue.toString());
		// create QueueSender
		try {
			queueSender = queueSession.createSender(queue);
		} catch (JMSException jmse) {
			jmse.printStackTrace(System.err);
		}

		System.out.println("QueueSender : " + queueSender.toString());
		// create TextMessage
		try {
			textMessage = queueSession.createTextMessage();
		} catch (JMSException jmse) {
			jmse.printStackTrace(System.err);
		}

		System.out.println("TextMessage : " + textMessage.toString());
		try {
			textMessage.setText(messageText);
		} catch (JMSException jmse) {
			jmse.printStackTrace(System.err);
		}

		System.out.println("TextMessage : " + textMessage.toString());
		// send message
		try {
			queueSender.send(textMessage);
		} catch (JMSException jmse) {
			jmse.printStackTrace(System.err);
		}

		System.out.println("Message sent.");
		// clean up
		try {
			textMessage = null;
			queueSender.close();
			queueSender = null;
			queue = null;
			queueSession.close();
			queueSession = null;
			queueConnection.close();
			queueConnection = null;
			queueConnectionFactory = null;
			initialContext = null;
		} catch (JMSException jmse) {
			jmse.printStackTrace(System.err);
		}

		System.out.println("Cleaned up done.");
	}

	public static void main(String args[]) {
		sendMessageToDestination("test");
	}
}

3) Create a consumer

This MDB consumer just prints out something in the log when it consumes the message in the queue.
The lifecycle methods are empty but they could be used to clean up resources for instance.

import javax.ejb.ActivationConfigProperty;
import javax.ejb.EJBException;
import javax.ejb.MessageDriven;
import javax.ejb.MessageDrivenBean;
import javax.ejb.MessageDrivenContext;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageListener;
import javax.jms.TextMessage;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

@MessageDriven(mappedName = "jms/QueueTest", activationConfig = {
		@ActivationConfigProperty(propertyName = "acknowledgeMode", propertyValue = "Auto-acknowledge"),
		@ActivationConfigProperty(propertyName = "destinationType", propertyValue = "javax.jms.Queue") })
public class TestJMSSABean implements MessageDrivenBean, MessageListener {

	/** The Constant LOGGER. */
	protected static final Logger LOGGER = LoggerFactory.getLogger(TestJMSSABean.class);

	public TestJMSSABean() {
	}

	@Override
	public void onMessage(Message message) {
		try {
			if (message instanceof TextMessage) {
				System.out.println(((TextMessage) message).getText());
				LOGGER.trace("***************** : " + ((TextMessage) message).getText());
			} else {
				System.out.println(message.getJMSMessageID());
				LOGGER.trace("***************** : " + message.getJMSMessageID());
			}
		} catch (JMSException ex) {
			LOGGER.trace("***************** ERROR : " + ex.getMessage());
		}
	}

	@Override
	public void ejbRemove() throws EJBException {
		// TODO Auto-generated method stub
	}

	@Override
	public void setMessageDrivenContext(MessageDrivenContext arg0) throws EJBException {
		// TODO Auto-generated method stub
	}
}
Categories: EJB, EJB 3.0, Java EE, WebLogic Server Tags:

Prevent Weblogic Server from wrapping data types

July 3rd, 2015 No comments

By default, Weblogic Server wraps data types such as Struct, Blob, Array, Clob, etc.

For instance, oracle.sql.STRUCT becomes weblogic.jdbc.wrapper.Struct_oracle_sql_STRUCT.

That can become a problem if for instance you’re expecting a data type :


oracle.sql.STRUCT objSTRUCT = (oracle.sql.STRUCT) callableStatement.getObject(2);

This would raise the following error :


java.lang.ClassCastException: weblogic.jdbc.wrapper.Struct_oracle_sql_STRUCT

To avoid it, one can simply disable that wrapping in the Weblogic administration console :

Go to Services > Data sources > Select your datasource > “Connection pools” tab > Advanced  :

uncheck “Wrap data types”

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Note : Weblogic Server version used is 10.3.5

Categories: Java EE, WebLogic Server Tags: