Consumer receives Single message from receive method in Apache ActiveMQ Artemis

Question

I am implementing Apache ActiveMQ Artemis in my project which connects to Artemis remote server. So I first decided to create a standalone project with producer and consumer.

import javax.jms.Connection;
import javax.jms.ConnectionFactory;
import javax.jms.Destination;
import javax.jms.MessageConsumer;
import javax.jms.MessageProducer;
import javax.jms.Queue;
import javax.jms.Session;
import javax.jms.TextMessage;
import javax.naming.Context;
import javax.naming.InitialContext;

import org.apache.activemq.artemis.api.jms.ActiveMQJMSClient;
import org.apache.activemq.artemis.utils.UUIDGenerator;

/**
 * A simple JMS Queue example that creates a producer and consumer on a queue and sends then receives a message.
 */
public class QueueExample {

   public static void main(final String[] args) throws Exception {
      Connection connection = null;

   try {

         ConnectionFactory cf = ActiveMQJMSClient.createConnectionFactory("tcp://54.67.23.67:61616",  UUIDGenerator.getInstance().generateStringUUID());
         // Step 4.Create a JMS Connection
         connection = cf.createConnection("test","test123");

         // Step 5. Create a JMS Session
         Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);

         // Step 6. Create a JMS Message Producer
         MessageProducer producer = session.createProducer(null);

         // Step 7. Create a Text Message
         TextMessage message1 = session.createTextMessage("This is a text message1");
         Thread.sleep(1000l);
         TextMessage message2 = session.createTextMessage("This is a text message2");


         System.out.println("Sent message: " + message1.getText());

         System.out.println("Sent message: " + message2.getText());

         Destination destination = session.createQueue("TESTQUEUE");

         // Step 8. Send the Message
         producer.send(destination,message1);
         producer.send(destination,message2);

         // Step 9. Create a JMS Message Consumer
         MessageConsumer messageConsumer = session.createConsumer(destination);

         // Step 10. Start the Connection
         connection.start();

         // Step 11. Receive the message
         TextMessage messageReceived = (TextMessage) messageConsumer.receive(5000);

         System.out.println("Received message: " + messageReceived.getText());
      } finally {
         // Step 12. Be sure to close our JMS resources!
         if (initialContext != null) {
            initialContext.close();
         }
         if (connection != null) {
            connection.close();
         }
      }
   }
}

I send message from producer 2 times, but while consuming I receive only 1 message. Below is the output I receive:

Received

Sent message: This is a text message1
Sent message: This is a text message2
Received message: This is a text message1

Expected

Sent message: This is a text message1
Sent message: This is a text message2
Received message: This is a text message1
Received message: This is a text message2

When I again run the code I get Received message: This is a text message2, but I want both messages Message1 and Message2 at the same time.

What is happening here? Can anyone please guide me, because I tried searching this issue but no results found.

Is my Artemis server not properly configured, or there is some issue with code?

Justin Bertram Justin Bertram · Accepted Answer · 2019-06-10T12:06:21

You are seeing the expected behavior. Calling receive will return at most 1 message. If you want to get more messages you need to call receive multiple times - once for each message you want to receive, e.g.:

TextMessage messageReceived = (TextMessage) messageConsumer.receive(5000);

System.out.println("Received message: " + messageReceived.getText());

messageReceived = (TextMessage) messageConsumer.receive(5000);

System.out.println("Received message: " + messageReceived.getText());

For additional information please see the JavaDoc for javax.jms.MessageConsumer.receive(long)

Consumer receives Single message from receive method in Apache ActiveMQ Artemis

1 Answers