loizenai | Mobile & Web Programming Tutorials

RabbitMQ Topic Exchange Spring Boot Example

– Tutorial: “RabbitMQ Topic Exchange Spring Boot Example” + Github Sourcecode

Topic exchange is powerful and can behave like other exchanges. In the tutorial, I show you how to build an example “RabbitMQ Topic Exchange Spring Boot Example” with github sourcecode.

* Technologies:
– Java 8
– Maven
– Spring Tool Suite
– Spring Boot
– RabbitMQ

RabbitMQ Topic Exchange

routing_key of messages sent to a topic exchange must be a list of words, delimited by dots, example:

– #.error
– *.prod.*
– sys.#

Note:
* (star) must be an exactly one word.
# (hash) can be zero or more words.

Springboot RabbitMQ Topic Exchange Architecture

With the above topic exchange design,
– when we send a message with routing key: sys.dev.info, it will just be delivered to Q1.
– when we send a message with routing key: app.prod.error, it will just be delivered to Q2.
– when we send a message with routing key: sys.test.error, it will be delivered to both queues {Q1, Q2}.

Topic exchange is strong tool and it can act as other exchanges as below:

– When a queue is bound with “#” (hash) binding key – it is as an fanout exchange.
– When don’t use * & # in bindings, it will behave as a direct exchange.

Practices – RabbitMQ Topic Exchange Spring Boot Example

In the tutorial, we create 2 SpringBoot project as below:

Springboot RabbitMQ Topic Project Structures

* Step to do:
– Create SpringBoot projects
– Define data model
– Implement RabbitMq Producer
– Implement RabbitMq consumer
– Run and check results

Create SpringBoot Projects

Using SpringToolSuite, create 2 SpringBoot projects, then add need dependency spring-boot-starter-amqp:


<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-amqp</artifactId>
</dependency>

Define Java Data Model

Create Log data model for both projects:


package com.loizenai.rabbitmq.model;

public class Log {
	private String content;
	private String routingKey;
	
	public Log(){};
	
	public Log(String content, String routingKey){
		this.content = content;
		this.routingKey = routingKey;
	}
	
	public String getContent(){
		return this.content;
	}
	
	public void setContent(String content){
		this.content = content;
	}
	
	public String getRoutingKey(){
		return this.routingKey;
	}
	
	public void setRoutingKey(String routingKey){
		this.routingKey = routingKey;
	}
	
	@Override
	public String toString() {
		return String.format("{content = %s, routingKey = %s}", content, routingKey);
	}
}

Configure SpringBoot RabbitMQ Producer – RabbitMQ Topic Exchange Spring Boot Example


package com.loizenai.rabbitmq.config;

import org.springframework.amqp.core.AmqpTemplate;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.amqp.support.converter.Jackson2JsonMessageConverter;
import org.springframework.amqp.support.converter.MessageConverter;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class RabbitMqConfig {
	
    @Bean
    public MessageConverter jsonMessageConverter(){
        return new Jackson2JsonMessageConverter();
    }
    
    public AmqpTemplate rabbitTemplate(ConnectionFactory connectionFactory) {
        final RabbitTemplate rabbitTemplate = new RabbitTemplate(connectionFactory);
        rabbitTemplate.setMessageConverter(jsonMessageConverter());
        return rabbitTemplate;
    }
}

Open application.properties, add configuration:


spring.rabbitmq.host=localhost
spring.rabbitmq.port=5672
spring.rabbitmq.username=guest
spring.rabbitmq.password=guest
jsa.rabbitmq.exchange=jsa.exchange.logs
jsa.rabbitmq.queue=jsa.queue
jsa.rabbitmq.routingkey=jsa.routingkey

Implement SpringBoot RabbitMq Producer – RabbitMQ Topic Exchange Spring Boot Example


package com.loizenai.rabbitmq.producer;

import org.springframework.amqp.core.AmqpTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

import com.loizenai.rabbitmq.model.Log;

@Component
public class Producer {
	
	@Autowired
	private AmqpTemplate amqpTemplate;
	
	@Value("${jsa.rabbitmq.exchange}")
	private String exchange;
	
	public void produce(Log logs){
		String routingKey = logs.getRoutingKey();
		amqpTemplate.convertAndSend(exchange, routingKey, logs);
		System.out.println("Send msg = " + logs);
	}
}

Implement SpringBoot RabbitMQ Producer Client


package com.loizenai.rabbitmq;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

import com.loizenai.rabbitmq.model.Log;
import com.loizenai.rabbitmq.producer.Producer;

@SpringBootApplication
public class SpringRabbitMqProducerApplication  implements CommandLineRunner{

	public static void main(String[] args) {
		SpringApplication.run(SpringRabbitMqProducerApplication.class, args);
	}
	
	@Autowired
	Producer producer;

	@Override
	public void run(String... args) throws Exception {
		
		/**
		 *  1
		 */
		String content = "2014-03-05 10:58:51.1  INFO 45469 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/7.0.52";
		String routingKey = "sys.dev.info";
		
		// send to RabbitMQ
		producer.produce(new Log(content, routingKey));
		
		/**
		 *  2
		 */
		content = "2017-10-10 10:57:51.10 ERROR in ch.qos.logback.core.joran.spi.Interpreter@4:71 - no applicable action for [springProperty], current ElementPath is [[configuration][springProperty]]";
		routingKey = "sys.test.error";
		
		// send to RabbitMQ
		producer.produce(new Log(content, routingKey));
		
		/**
		 *  3
		 */
		content = "2017-10-10 10:57:51.112  ERROR java.lang.Exception: java.lang.Exception";
		routingKey = "app.prod.error";
		
		// send to RabbitMQ
		producer.produce(new Log(content, routingKey));
	}
}

Configure SpringBoot RabbitMq Consumer


package com.loizenai.rabbitmq.config;

import org.springframework.amqp.rabbit.config.SimpleRabbitListenerContainerFactory;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.support.converter.Jackson2JsonMessageConverter;
import org.springframework.amqp.support.converter.MessageConverter;
import org.springframework.boot.autoconfigure.amqp.SimpleRabbitListenerContainerFactoryConfigurer;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class RabbitMqConfig {
	
    @Bean
    public MessageConverter jsonMessageConverter(){
        return new Jackson2JsonMessageConverter();
    }
    
    @Bean
    public SimpleRabbitListenerContainerFactory jsaFactory(ConnectionFactory connectionFactory,
            SimpleRabbitListenerContainerFactoryConfigurer configurer) {
        SimpleRabbitListenerContainerFactory factory = new SimpleRabbitListenerContainerFactory();
        configurer.configure(factory, connectionFactory);
        factory.setMessageConverter(jsonMessageConverter());
        return factory;
    }
}

Open application.properties, add configuration:


spring.rabbitmq.host=localhost
spring.rabbitmq.port=5672
spring.rabbitmq.username=guest
spring.rabbitmq.password=guest
jsa.rabbitmq.queue=jsa.logs.sys
#jsa.rabbitmq.queue=jsa.logs.prod.error

Implement Spring Boot Consumer


package com.loizenai.rabbitmq.consumer;

import org.apache.commons.logging.Log;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;


@Component
public class Consumer {
	
	@RabbitListener(queues="${jsa.rabbitmq.queue}", containerFactory="jsaFactory")
    public void recievedMessage(Log logs) {
        System.out.println("Recieved Message: " + logs);
    }
}

Run and Check Results

– Setup RabbitMq Exchange, Queues:

Enable rabbitmq_management by cmd: rabbitmq-plugins enable rabbitmq_management --online

Then go to: http://localhost:15672 -> login with user/password: guest/guest

Spring Boot RabbitMQ Topic Exchange Connection

– Add exchange:

Go to http://localhost:15672/#/exchanges, add exchange: jsa.exchange.logs

Springboot Rabbitmq Topic Exchange - Create Exchange — Springboot Rabbitmq Topic Exchange – Create Exchange

– Add Queue:

Go to http://localhost:15672/#/queues, add 2 queues: jsa.logs.sys, jsa.logs.prod.error.

– Binding the queues with above exchange:

SpringBoot RabbitMQ Topic Exchange Bindling

Run & Check Results

– Run SpringBoot-RabbitMQ-Producer with commandline mvn spring-boot:run.

– Console’s logs:


Send msg = {content = 2014-03-05 10:58:51.1  INFO 45469 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/7.0.52, routingKey = sys.dev.info}
Send msg = {content = 2017-10-10 10:57:51.10 ERROR in ch.qos.logback.core.joran.spi.Interpreter@4:71 - no applicable action for [springProperty], current ElementPath is [[configuration][springProperty]], routingKey = sys.test.error}
Send msg = {content = 2017-10-10 10:57:51.112  ERROR java.lang.Exception: java.lang.Exception, routingKey = app.prod.error}

– See queues’ status:

SpringBoot RabbitMQ Topic Message Queue After Sending

– Run Spring-Boot-RabbitMQ-Consumer which listen to jsa.logs.sys queue with configuration: jsa.rabbitmq.queue=jsa.logs.sys:

– Console’s logs:


Recieved Message: {content = 2014-03-05 10:58:51.1  INFO 45469 --- [           main] org.apache.catalina.core.StandardEngine  : Starting Servlet Engine: Apache Tomcat/7.0.52, routingKey = sys.dev.info}
Recieved Message: {content = 2017-10-10 10:57:51.10 ERROR in ch.qos.logback.core.joran.spi.Interpreter@4:71 - no applicable action for [springProperty], current ElementPath is [[configuration][springProperty]], routingKey = sys.test.error}

– See queues’s status:

SpringBoot RabbitMQ Topic After Consume in jsa.logs_.sys_

– Run Spring-Boot-RabbitMQ-Consumer which listen to jsa.logs.prod.error queue with configuration: jsa.rabbitmq.queue=jsa.logs.prod.error:

– Console’s Logs:


Recieved Message: {content = 2017-10-10 10:57:51.10 ERROR in ch.qos.logback.core.joran.spi.Interpreter@4:71 - no applicable action for [springProperty], current ElementPath is [[configuration][springProperty]], routingKey = sys.test.error}
Recieved Message: {content = 2017-10-10 10:57:51.112  ERROR java.lang.Exception: java.lang.Exception, routingKey = app.prod.error}

– See queues’s status:

SpringBoot RabbitMQ Topic After Consume in jsa.logs_.prod_.error_

– Reference Link: RabbitMQ Topic Exchange

Source Code

SpringBoot-RabbitMQ-Producer
Spring-RabbitMQ-Consumer

RabbitMQ Publish/Subscribe Java Example + SpringBoot

– Tutorial “Rabbitmq Publish/Subscribe Java Example with SpringBoot”

In the tutorial, I guide how to create Spring RabbitMq Publish/Subcribe pattern by using fanout exchanges of RabbitMQ and SpringBoot.

Spring RabbitMq Publish/Subcribe pattern – RabbitMQ Publish/Subscribe Java Example + SpringBoot

We create a Publisher, and 3 Subcribers and using fanout exchanges of RabbitMQ for create a Publish/Subcribe Pattern System:

* Flow messages:

– Publisher will send messages to the fanout exchange.
– The fanout exchange routes messages to all of the queues that are bound to it and the routing key is ignored.
– Subcribers instances recieves messages from the queues.

Practice – Rabbitmq Publish/Subscribe Java Example + SpringBoot

* Technologies:

– Java 8
– Maven 3.6.1
– Spring Tool Suite
– Spring Boot
– RabbitMQ

We create 2 SpringBoot projects {Publisher, Subcriber}:

* Step to do:
– Create SpringBoot projects
– Create Publiser/Subcriber
– Setup RabbitMQ exchange, queues
– Run and check results

Create SpringBoot projects – RabbitMQ Publish/Subscribe Java Example + SpringBoot

Using Spring Tool Suite, create 2 Spring Starter Projects then add amqp dependency for both of them:


<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-amqp</artifactId>
</dependency>

– With Spring-Rabbit-MQ-Publiser, we add more web dependency for creating RestController:


<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>

Create SpringBoot RabbitMQ Publisher – RabbitMQ Publish/Subscribe Java Example + SpringBoot

– Add RabbitMq configuration:


spring.rabbitmq.host=localhost
spring.rabbitmq.port=5672
spring.rabbitmq.username=guest
spring.rabbitmq.password=guest
jsa.rabbitmq.exchange=jsa.fanout

– Implement RabbitMQ Publisher:


package com.loizenai.rabbitmq.publisher;

import org.springframework.amqp.core.AmqpTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Component;

@Component
public class Publisher {
	
	@Autowired
	private AmqpTemplate amqpTemplate;
	
	@Value("${jsa.rabbitmq.exchange}")
	private String exchange;
	
	public void produceMsg(String msg){
		amqpTemplate.convertAndSend(exchange, "",msg);
		System.out.println("Send msg = " + msg);
	}
}

– Implement a sending RestAPI:


package com.loizenai.rabbitmq.web;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestParam;
import org.springframework.web.bind.annotation.RestController;

import com.loizenai.rabbitmq.publisher.Publisher;

@RestController
public class WebController {
	
	@Autowired
	Publisher publisher;
	
	@RequestMapping("/send")
	public String sendMsg(@RequestParam("msg")String msg){
		publisher.produceMsg(msg);
		return "Done";
	}
}

Create Spring RabbitMQ Subcriber

– Add RabbitMq configuration:


spring.rabbitmq.host=localhost
spring.rabbitmq.port=5672
spring.rabbitmq.username=guest
spring.rabbitmq.password=guest
jsa.rabbitmq.queue=jsa.queue.1

– Create RabbitMQ Subcriber:


package com.loizenai.rabbitmq.subcriber;

import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.stereotype.Component;

@Component
public class Subcriber {

	@RabbitListener(queues="${jsa.rabbitmq.queue}")
    public void recievedMessage(String msg) {
        System.out.println("Recieved Message: " + msg);
    }
}

Setup RabbitMQ Exchange, Queues – RabbitMQ Publish/Subscribe Java Example + SpringBoot

Enable rabbitmq_management by cmd: rabbitmq-plugins enable rabbitmq_management --online

Go to: http://localhost:15672. Then login with user/password: guest/guest.

– Add an RabbitMQ Exchange:

Create a fanout exchange: jsa.fanout

– Add RabbitMQ Queues:

Create 3 RabbitMq queues {jsa.queue.1, jsa.queue.2, jsa.queue.3}:

Binding all above queues with the fanout exchange jsa.fanout:

Run and Check results

Build 2 SpringBoot projects {Publisher, Subcriber} with the commandline: mvn clean install.

Run Publisher with commandline: mvn spring-boot:run, then send a message by a request: localhost:8080/send?msg=Hello World!

– See status of the Queues:

Run 3 Subcriber instances which different configured values of jsa.rabbitmq.queue: {jsa.queue.1, jsa.queue.2, jsa.queue.3}.

See console logs of each Subcriber instances, we got the same message: ‘Recieved Message: Hello World!’.

– Again, check status of the queues:

– All messages has been consumed by Subcribers.

– Reference Link: RabbitMQ Publish/Subscribe

SourceCode – RabbitMQ Publish/Subscribe Java Example + SpringBoot

– SpringBoot-RabbitMQ-Publisher
– SpringBoot-RabbitMQ-Subcriber

Category: RabbitMQ