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Table of Contents
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Introduction

This sample demonstrates how persistent queues can be created and used in WSO2 Message Broker using the JMS API. It first introduces a sample JMS client named named QueueSender which  which is used to send messages to a known, created queue in WSO2 Message Broker. Then it introduces a sample JMS client named named QueueReceiver to  to receive messages and print them in the console.

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Prerequisites

See Prerequisites to Run the MB Samples for a list of prerequisites.

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About the sample

The <MB_HOME>/Samples/JMSQueueClient/src/org/sample/jms directory has the following classes:

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titleSampleQueueSender.java

This class is used to create the sample client which sends messages to the queue named

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 testQueue in WSO2 MB. The

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code of this class is as follows

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:

Code Block
languagejava

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package org.sample.jms;
import javax.jms.JMSException;
import javax.jms.Queue;
import javax.jms.QueueConnection;
import javax.jms.QueueConnectionFactory;
import javax.jms.QueueSession;
import javax.jms.TextMessage;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import java.util.Properties;
public class SampleQueueSender {
    public static final String QPID_ICF = "org.wso2.andes.jndi.PropertiesFileInitialContextFactory";
    private static final String CF_NAME_PREFIX = "connectionfactory.";
    private static final String QUEUE_NAME_PREFIX = "queue.";
    private static final String CF_NAME = "qpidConnectionfactory";
    String userName = "admin";
    String password = "admin";
    private static String CARBON_CLIENT_ID = "carbon";
    private static String CARBON_VIRTUAL_HOST_NAME = "carbon";
    private static String CARBON_DEFAULT_HOSTNAME = "localhost";
    private static String CARBON_DEFAULT_PORT = "5672";
    String queueName = "testQueue";
    private QueueConnection queueConnection;
    private QueueSession queueSession;
    public void sendMessages() throws NamingException, JMSException {
        Properties properties = new Properties();
        properties.put(Context.INITIAL_CONTEXT_FACTORY, QPID_ICF);
        properties.put(CF_NAME_PREFIX + CF_NAME, getTCPConnectionURL(userName, password));
        properties.put(QUEUE_NAME_PREFIX + queueName, queueName);
        InitialContext ctx = new InitialContext(properties);
        // Lookup connection factory
        QueueConnectionFactory connFactory = (QueueConnectionFactory) ctx.lookup(CF_NAME);
        queueConnection = connFactory.createQueueConnection();
        queueConnection.start();
        queueSession = queueConnection.createQueueSession(false, QueueSession.AUTO_ACKNOWLEDGE);
        // Send message
        Queue queue = (Queue)ctx.lookup(queueName);
        // create the message to send
        TextMessage textMessage = queueSession.createTextMessage("Test Message Content");
        

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javax.jms.QueueSender queueSender = queueSession.createSender(queue);
        

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queueSender.

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send(textMessage);
        

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queueSender.close();
        

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queueSession.close();
        

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queueConnection.close();
    }
   

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 private 

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String 

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getTCPConnectionURL(String username, String password) {
        

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// amqp://{username}:{password}@carbon/carbon?brokerlist='tcp://{hostname}:{port}'
        return new StringBuffer()
 

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  .append("amqp://").append(username).append(":").append(password)
           

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 .append("@").append(CARBON_CLIENT_ID)
        

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.append("/").append(CARBON_VIRTUAL_HOST_NAME)
        

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.

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append("?brokerlist='tcp://").append(CARBON_DEFAULT_HOSTNAME).append(":").append(CARBON_DEFAULT_PORT).append("'")
       

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.

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toString();
    }
 

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SampleQueueReceiver.java class is used to create the sample client which receives the message sent to the testQueue queue and prints it in the console. The configuration of this class is as follows.

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languagejava

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}
Localtab
titleSampleQueueReceiver.java

This class is used to create the sample client which receives the message sent to the testQueue queue and prints it in the console. The code of this class is as follows:

Code Block
languagejava
package org.sample.jms;
import javax.jms.JMSException;
import javax.jms.Queue;
import javax.jms.QueueConnection;
import javax.jms.QueueConnectionFactory;
import javax.jms.QueueSession;
import javax.jms.TextMessage;
import javax.jms.MessageConsumer;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.naming.NamingException;
import java.util.Properties;
public class SampleQueueReceiver {
    public static final String QPID_ICF = "org.wso2.andes.jndi.PropertiesFileInitialContextFactory";
    private static final String 

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CF_

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NAME_

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PREFIX = "

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connectionfactory.";
    private static final String 

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CF_

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NAME = "

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qpidConnectionfactory";
    String 

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userName = "

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admin";
    

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String 

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password 

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= "admin";
  

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private 

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static 

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String CARBON_CLIENT_ID = "carbon";
    private static 

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String CARBON_VIRTUAL_HOST_NAME = 

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"carbon";
    private static 

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String CARBON_DEFAULT_HOSTNAME = "localhost";
    private static 

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String CARBON_DEFAULT_PORT = "5672";
    String queueName = "testQueue";
    private QueueConnection queueConnection;
    private QueueSession queueSession;
 

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public 

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MessageConsumer 

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registerSubscriber(

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)

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 throws NamingException, JMSException{
     

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Properties 

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properties = new Properties();
     

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properties.put(Context.INITIAL_CONTEXT_FACTORY, QPID_ICF);
       

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 properties.put(CF_NAME_PREFIX + CF_NAME, getTCPConnectionURL(userName, password));
        

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properties.

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put("queue."+ queueName,queueName);
        InitialContext 

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ctx = 

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new InitialContext(properties);
        // 

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Lookup connection 

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factory
        

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QueueConnectionFactory 

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connFactory = (

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QueueConnectionFactory) ctx.lookup(

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CF_NAME);
        

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queueConnection 

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= connFactory.createQueueConnection();
        

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queueConnection.start();
        

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queueSession =

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queueConnection.createQueueSession(false, QueueSession.AUTO_ACKNOWLEDGE);
        

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//Receive message
        Queue queue =  (Queue) 

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ctx.

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lookup(queueName);
    

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    MessageConsumer 

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consumer 

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= 

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queueSession.createConsumer(queue);
        

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return consumer;
    }
    

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public 

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void 

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receiveMessages(MessageConsumer consumer) throws NamingException, JMSException {
        TextMessage message = (TextMessage) consumer.

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receive();
        System.out.println("Got message from queue receiver==>" + message.getText());
        // 

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Housekeeping
        consumer.close();
        

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queueSession.close();
        queueConnection.stop();
        queueConnection.

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close();
    }
    private String 

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The Main.java class defines the main method for calling both the clients mentioned above. The configuration of this class is as follows.

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languagejava

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getTCPConnectionURL(String username, String password) {
        // amqp://{username}:{password}@carbon/carbon?brokerlist='tcp://{hostname}:{port}'
        return new StringBuffer()
                .append("amqp://").append(username).append(":").append(password)
                .append("@").append(CARBON_CLIENT_ID)
                .append("/").append(CARBON_VIRTUAL_HOST_NAME)
                .append("?brokerlist='tcp://").append(CARBON_DEFAULT_HOSTNAME).append(":").append(CARBON_DEFAULT_PORT).append("'")
                .toString();
    }
 
}
Localtab
titleMain.java

The Main.java class defines the main method for calling both the clients mentioned above. The code of this class is as follows:

Code Block
languagejava
package org.sample.jms;
import javax.jms.JMSException;
import javax.jms.MessageConsumer;
import javax.naming.NamingException;

public class Main {
	public static void main(String[] args) throws NamingException, JMSException {
        SampleQueueReceiver queueReceiver = new SampleQueueReceiver();
        MessageConsumer consumer = queueReceiver.registerSubscriber();
        SampleQueueSender queueSender = new SampleQueueSender();
        queueSender.sendMessages();
        queueReceiver.receiveMessages(consumer);
    }
}
Info

The following should be noted if you are writing a similar sample:

  • It is not possible to use the @ symbol in the username or password.

    It is also not possible to use the percentage (%) sign in the password. When building the connection string URL inside the andes client code of MB, the URL is parsed. This parsing exception happens because the percentage (%) sign acts as the escape character in URL parsing. If using the percentage (%) sign in the connection string is required, use the respective encoding character for the percentage (%) sign in the connection string. For example:

    If you need to pass adm%in as the password, then the % should be encoded with its respective URL encoding character. Therefore, you have to send it as adm%25in.

    For a list of possible URL parsing patterns, see URL encoding reference.
     

  • In addition to using javax.jms.QueueSender class to send the messages you can also use a javax.jms.MessageProducer client and send the messages to a destination queue. Following is the way of creating a JMS MessageProducer.

    javax.jms.MessageProducer messageProducer = queueSession.createProducer(queue);

    messageProducer.send(textMessage);

    messageProducer.close();
     

  • When subscribing and publishing to a queue in a tenant the qualified queue name, DOMAIN_NAME/Queuename should be given as follows.

    String queueName = "mydomain.com/testQueue";

    Queue queue = (Queue) ctx.lookup(queueName);

    See Managing Tenant-specific Subscriptions for more information.

 

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Building the sample

Run the ant command from <MB_HOME>/Samples/JMSQueueClient directory.

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