Spring Boot [Publisher- Subscriber] - Rabbit MQ using Docker
RabbitMQ is an open-source message-broker software that originally implemented the Advanced Message Queuing Protocol and has since been extended with a plug-in architecture to support Streaming Text Oriented Messaging Protocol, MQ Telemetry Transport, and other protocols.
JMS[Java Message Service] is a service used to send messages between a subscriber and a publisher. The Publisher adds the message in a queue and a Subscriber[service] can access that message from the queue.
There are different Messaging services such as:-
1) Rabbit MQ
2) Active MQ
3) Feign Client
4) Kafka
We will be using Rabbit MQ for this project.
Docker is required to be installed on the machine.
Installation
1) Clone the Repo from here Click Here & run the following commands.
docker-compose up
Output
Post a request using Postman on:-
localhost:8081/order/taj
Send this in body:-
{
"name" : "Sandwitch",
"qty" : 2,
"price" : 212
}
Usage
MessagingConfig.java
@Configuration
public class MessagingConfig {
@Bean
public Queue queue() {
return new Queue(Constants.QUEUE);
}
@Bean
public TopicExchange exchange() {
return new TopicExchange(Constants.EXCHANGE);
}
@Bean
public Binding binding(Queue queue , TopicExchange exchange) {
return BindingBuilder.bind(queue).to(exchange).with(Constants.ROUTING_KEY);
}
@Bean
public MessageConverter converter() {
return new Jackson2JsonMessageConverter();
}
@Bean
public AmqpTemplate template(ConnectionFactory connectionFactory) {
final RabbitTemplate rabbitTemplate = new RabbitTemplate(connectionFactory);
rabbitTemplate.setMessageConverter(converter());
return rabbitTemplate;
}
}
OrderPublisher.java
@RestController
@RequestMapping("/order")
public class OrderPublisher {
@Autowired
private RabbitTemplate rabbitTemplate;
@PostMapping("/{restaurantName}")
public String bookOrder(@RequestBody Order order, @PathVariable String restaurantName ) {
order.setOrderId(UUID.randomUUID().toString());
OrderStatus orderStatus = new OrderStatus(order, "PROCESS", "Order Successfully Placed"+ restaurantName);
rabbitTemplate.convertAndSend(Constants.EXCHANGE,Constants.ROUTING_KEY, orderStatus);
return "success!!";
}
}
User.java (consumer)
@Component
public class User {
@RabbitListener(queues = Constants.QUEUE )
public void consumeMessageFromQueue(OrderStatus orderStatus) {
System.out.println("Message Received from queue: " +orderStatus );
}
}
Constants.java
Constants are defined in the class.
public class Constants {
public static final String QUEUE = "rabbit_queue";
public static final String EXCHANGE = "rabbit_exchange";
public static final String ROUTING_KEY = "rabbit_routingKey";
}
Configuration
docker-compose.yml
version: '3.3'
services:
#service 1: definition of mysql database
rabbitmq:
image: rabbitmq:3-management
container_name: rabbitmq
restart: always
ports:
- "15672:15672"
- "5672:5672"
#service 3: definition of your spring-boot app
orderservice: #it is just a name, which will be used only in this file.
image: order-service #name of the image after dockerfile executes
container_name: order-service-app #name of the container created from docker image
build:
context: . #docker file path (. means root directory)
dockerfile: Dockerfile #docker file name
ports:
- "8081:8080" #docker containter port with your os port
restart: always
environment:
- SPRING_RABBITMQ_HOST=rabbitmq
depends_on: #define dependencies of this app
- rabbitmq #dependency name (which is defined with this name 'db' in this file earlier)
Dockerfile
FROM openjdk:11 as rabbitmq
EXPOSE 8081
WORKDIR /app
# Copy maven executable to the image
COPY mvnw .
COPY .mvn .mvn
# Copy the pom.xml file
COPY pom.xml .
# Copy the project source
COPY ./src ./src
COPY ./pom.xml ./pom.xml
RUN chmod 755 /app/mvnw
RUN ./mvnw package -DskipTests
ENTRYPOINT ["java","-jar","target/springboot-demo-activemq-0.0.1-SNAPSHOT.jar"]
Top comments (0)