Getting Started

Description

• Create a Sender
• Create a Reciever
• Run an Application

Prerequisites

• JDK 21
• Maven
• Docker
• IntelliJ IDEA

Project Structure

.
├── pom.xml
└── src
    ├── main
    │   ├── java
    │   │   └── org
    │   │       └── example
    │   │           ├── CommonConfigs.java
    │   │           ├── MessagePublisher.java
    │   │           └── MessageSubscriber.java
    │   └── resources
    └── test
        └── java

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>org.example</groupId>
    <artifactId>rabbitmq-getting-started</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>22</maven.compiler.source>
        <maven.compiler.target>22</maven.compiler.target>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    </properties>

    <dependencies>
        <dependency>
            <groupId>com.rabbitmq</groupId>
            <artifactId>amqp-client</artifactId>
            <version>5.24.0</version>
        </dependency>
    </dependencies>
</project>

CommonConfigs.java

package org.example;

public class CommonConfigs {
  public static final String DEFAULT_QUEUE = "Queue-Getting-Started";
  public static final String AMQP_URL = "amqp://guest:guest@localhost:5672/";
}

MessagePublisher.java

package org.example;

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

public class MessagePublisher {
  public static void main(String[] args) throws Exception {
    ConnectionFactory factory = new ConnectionFactory();
    Connection connection = factory.newConnection(CommonConfigs.AMQP_URL);
    Channel channel = connection.createChannel();

    channel.queueDeclare(CommonConfigs.DEFAULT_QUEUE, true, false, false, null);
    for (int i = 0; i < 4; i++) {
      String message = CommonConfigs.DEFAULT_QUEUE + " with rabbitMQ - Msg" + i;
      //publish - (exchange, routingKey, properties, message)
      channel.basicPublish("", CommonConfigs.DEFAULT_QUEUE, null, message.getBytes());
    }
    channel.close();
    connection.close();
  }
}

MessageSubscriber.java

package org.example;

import com.rabbitmq.client.*;

import java.io.IOException;
import java.util.concurrent.TimeoutException;

public class MessageSubscriber {

  public static void main(String[] args) throws IOException, TimeoutException {
    ConnectionFactory factory = new ConnectionFactory();
    Connection connection = factory.newConnection(CommonConfigs.AMQP_URL);
    Channel channel = connection.createChannel();

    DeliverCallback deliverCallback = (s, delivery) -> {
      System.out.println(new String(delivery.getBody(), "UTF-8"));
    };

    CancelCallback cancelCallback = s -> {
      System.out.println(s);
    };
    channel.basicConsume(CommonConfigs.DEFAULT_QUEUE, true, deliverCallback, cancelCallback);
  }
}

Running

Intellij IDE:

Run:

MessagePublisher

MessageSubscriber
Output:

Queue-Getting-Started with rabbitMQ - Msg0
Queue-Getting-Started with rabbitMQ - Msg1
Queue-Getting-Started with rabbitMQ - Msg2
Queue-Getting-Started with rabbitMQ - Msg3

---

Source Code:
https://github.com/ZbCiok/zjc-examples/tree/main/reactive-messaging/rabbitmq/rabbitmq-getting-started