Consuming messages from a message queue

[asn11]

HI I am working on a requirement where an existing application in ecosystem creates messages(which are metadata updates to products) .These are sent to a message queue.

In AEM I have to consume these messages from queues.

Looking for an example where rabitmq is used in an osgi service to consume messages from a queue.

Any help is welcome:)

Thanks in advance.

[smacdonald2008]

I am not aware of any examples or community articles that show use of this. May make a good community article. 

If there is a Java API - I would think first step is to use that Java API within a custom AEM service. 

When i use to work on Adobe Data Services - that product had a Message Service: 

http://scottsdigitalcommunity.blogspot.ca/2011/12/create-mobile-applications-for-data.html

But AEM does not have a Message Service. 

[kautuk_sahni · Accepted solution]

Hi 

Whatever things that are possible in Java is possible here in AEM. 

I have not worked on "rabbitmw", but by looking at its documentation, "rabbitmq" provide a java client (http://www.rabbitmq.com/java-client.html).

Using it, we can write Sender and Receiver. 

Sender:            

import com.rabbitmq.client.Channel;
import com.rabbitmq.client.Connection;
import com.rabbitmq.client.ConnectionFactory;

public class Send {

  private final static String QUEUE_NAME = "hello";

  public static void main(String[] argv) throws Exception {
    ConnectionFactory factory = new ConnectionFactory();
    factory.setHost("localhost");
    Connection connection = factory.newConnection();
    Channel channel = connection.createChannel();

    channel.queueDeclare(QUEUE_NAME, false, false, false, null);
    String message = "Hello World!";
    channel.basicPublish("", QUEUE_NAME, null, message.getBytes("UTF-8"));
    System.out.println(" [x] Sent '" + message + "'");

    channel.close();
    connection.close();
  }
}

Receiver:-

import com.rabbitmq.client.*;

import java.io.IOException;

public class Recv {

  private final static String QUEUE_NAME = "hello";

  public static void main(String[] argv) throws Exception {
    ConnectionFactory factory = new ConnectionFactory();
    factory.setHost("localhost");
    Connection connection = factory.newConnection();
    Channel channel = connection.createChannel();

    channel.queueDeclare(QUEUE_NAME, false, false, false, null);
    System.out.println(" [*] Waiting for messages. To exit press CTRL+C");

    Consumer consumer = new DefaultConsumer(channel) {
      @Override
      public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body)
          throws IOException {
        String message = new String(body, "UTF-8");
        System.out.println(" [x] Received '" + message + "'");
      }
    };
    channel.basicConsume(QUEUE_NAME, true, consumer);
  }
}

You can create a service in AEM to do so (https://helpx.adobe.com/experience-manager/using/aem_wordpress.html). 

AEM-rabbitmw reference martial :-  https://github.com/viveksachdeva/aem-utils

Blog link: - http://vivekaem.blogspot.in/2015/07/aem-implement-queue-using-rabbitmq.html

I hope this would be helpful to you.

Thanks and Regards

Kautuk Sahni