Connecting to an Instance Without SSL

The following demo shows how to access and use a RabbitMQ instance in a VPC, assuming that the RabbitMQ client is deployed in an ECS.

RabbitMQ instances are compatible with the open-source RabbitMQ protocol. To access a RabbitMQ instance in your service code, see the tutorials for different languages at https://www.rabbitmq.com/getstarted.html.

Prerequisites

A RabbitMQ instance has been created following the instructions in Step 2: Create a RabbitMQ Instance, and the username and password used to create the instance have been obtained.
The Instance Address (Private Network) or Instance Address (Public Network) of the instance has been recorded from the instance details.
An ECS has been created, and its VPC, subnet, and security group configurations are the same as those of the RabbitMQ instance.
You have installed the JDK and configured the environment variables. For details, see Step 1: Prepare the Environment.

Accessing the Instance Using CLI

Run the following command to download RabbitMQ-Tutorial.zip:

$ wget https://dms-demo.obs.cn-north-1.myhuaweicloud.com/RabbitMQ-Tutorial.zip

Run the following command to decompress RabbitMQ-Tutorial.zip:
```
$ unzip RabbitMQ-Tutorial.zip
```
Run the following command to navigate to the RabbitMQ-Tutorial directory, which contains the precompiled JAR file:
```
$ cd RabbitMQ-Tutorial
```
Create messages using the sample project.
```
$ java -cp .:rabbitmq-tutorial.jar Send host port user password
```
host indicates the connection address for accessing the instance. port is the listening port of the instance, which is 5672 by default. user and password indicate the username and password used for accessing the instance.

Figure 1 Sample project for message creation

Press Ctrl+C to exit.
Retrieve messages using the sample project.
```
$ java -cp .:rabbitmq-tutorial.jar Recv host port user password
```
host indicates the connection address for accessing the instance. port is the listening port of the instance, which is 5672 by default. user and password indicate the username and password used for accessing the instance.

Figure 2 Sample project for message retrieval

To stop retrieving messages, press Ctrl+C to exit.

Java Sample Code

Accessing an instance and creating messages

ConnectionFactory factory = new ConnectionFactory();
 factory.setHost(host);
 factory.setPort(port);

 factory.setUsername(user);
 factory.setPassword(password);
 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();

Accessing an instance and retrieving messages

ConnectionFactory factory = new ConnectionFactory();
 factory.setHost(host);
 factory.setPort(port);
 factory.setUsername(user);
 factory.setPassword(password);
 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);