Parameter 0 of method listenerAdapter in "package/class" required a bean of type 'com.example.messagingrabbitmq.Receiver' that could not be found

Hеllo, all,

I am building a simple RabbitMQ AMQP server with Spring/Docker to run the server itself and I am following this guide: https://spring.io/guides/gs/messaging-rabbitmq/#scratch

The classes are literally copied from there.

I have 3 classes in src/main/java/com.example.messagingrabbitmq and they are the following:

MessagingRabbitmqApplication:

package com.example.messagingrabbitmq;
import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.Queue;
import org.springframework.amqp.core.TopicExchange;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer;
import org.springframework.amqp.rabbit.listener.adapter.MessageListenerAdapter;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
@SpringBootApplication
public class MessagingRabbitmqApplication {
static final String topicExchangeName = "spring-boot-exchange";
static final String queueName = "spring-boot";
@Bean
Queue queue() {
return new Queue(queueName, false);
}
@Bean
TopicExchange exchange() {
return new TopicExchange(topicExchangeName);
}
@Bean
Binding binding(Queue queue, TopicExchange exchange) {
return BindingBuilder.bind(queue).to(exchange).with("foo.bar.#");
}
@Bean
SimpleMessageListenerContainer container(ConnectionFactory connectionFactory,
MessageListenerAdapter listenerAdapter) {
SimpleMessageListenerContainer container = new SimpleMessageListenerContainer();
container.setConnectionFactory(connectionFactory);
container.setQueueNames(queueName);
container.setMessageListener(listenerAdapter);
return container;
}
@Bean
MessageListenerAdapter listenerAdapter(Receiver receiver) {
return new MessageListenerAdapter(receiver, "receiveMessage");
}
public static void main(String[] args) throws InterruptedException {
SpringApplication.run(MessagingRabbitmqApplication.class, args).close();
}
}

Receiver:

package com.example.messagingrabbitmq;
import java.util.concurrent.CountDownLatch;
import org.springframework.stereotype.Component;
@Component
public class Receiver {
private CountDownLatch latch = new CountDownLatch(1);
public void receiveMessage(String message) {
System.out.println("Received <" + message + ">");
latch.countDown();
}
public CountDownLatch getLatch() {
return latch;
}
}

Runner:

package com.example.messagingrabbitmq;
import java.util.concurrent.TimeUnit;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.boot.CommandLineRunner;
import org.springframework.stereotype.Component;
@Component
public class Runner implements CommandLineRunner {
private final RabbitTemplate rabbitTemplate;
private final Receiver receiver;
public Runner(Receiver receiver, RabbitTemplate rabbitTemplate) {
this.receiver = receiver;
this.rabbitTemplate = rabbitTemplate;
}
@Override
public void run(String... args) throws Exception {
System.out.println("Sending message...");
rabbitTemplate.convertAndSend(MessagingRabbitmqApplication.topicExchangeName, "foo.bar.baz", "Hello from RabbitMQ!");
receiver.getLatch().await(10000, TimeUnit.MILLISECONDS);
}
}

I tried to run the program from the MessagingRabbitmqApplication java class, but resulted in the following error:

Description:
Parameter 0 of method listenerAdapter in com.example.messagingrabbitmq.MessagingRabbitmqApplication required a bean of type 'com.example.messagingrabbitmq.Receiver' that could not be found.
Action:
Consider defining a bean of type 'com.example.messagingrabbitmq.Receiver' in your configuration.
Process finished with exit code 1

I tried to create a Receiver Bean in Receiver.java class with the following, but it resulted in the same error:

   @Bean
Receiver receiver() {
return new Receiver();
}

I also have a question on how to set up my application.properties file so the Queues/Exchanges can be set up in my running Docker container? It is currently running on 'localhost:15672'.

Thank you very much for the help in advance.

Update:

I checked your existing code, it's working fine.

TestAmqpApplication :

package com.example.testamqp;
import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.Queue;
import org.springframework.amqp.core.TopicExchange;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.listener.SimpleMessageListenerContainer;
import org.springframework.amqp.rabbit.listener.adapter.MessageListenerAdapter;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
@SpringBootApplication
public class TestAmqpApplication {
static final String topicExchangeName = "spring-boot-exchange";
static final String queueName = "spring-boot";
@Bean
Queue queue() {
return new Queue(queueName, false);
}
@Bean
TopicExchange exchange() {
return new TopicExchange(topicExchangeName);
}
@Bean
Binding binding(Queue queue, TopicExchange exchange) {
return BindingBuilder.bind(queue).to(exchange).with("foo.bar.#");
}
@Bean
SimpleMessageListenerContainer container(ConnectionFactory connectionFactory,
MessageListenerAdapter listenerAdapter) {
SimpleMessageListenerContainer container = new SimpleMessageListenerContainer();
container.setConnectionFactory(connectionFactory);
container.setQueueNames(queueName);
container.setMessageListener(listenerAdapter);
return container;
}
@Bean
MessageListenerAdapter listenerAdapter(Receiver receiver) {
return new MessageListenerAdapter(receiver, "receiveMessage");
}
public static void main(String[] args) {
SpringApplication.run(TestAmqpApplication.class, args);
}
} 

Receiver:

package com.example.testamqp;
import org.springframework.stereotype.Component;
import java.util.concurrent.CountDownLatch;
@Component
public class Receiver {
private CountDownLatch latch = new CountDownLatch(1);
public void receiveMessage(String message) {
System.out.println("Received <" + message + ">");
latch.countDown();
}
public CountDownLatch getLatch() {
return latch;
}
}

Runner:

package com.example.testamqp;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.boot.CommandLineRunner;
import org.springframework.stereotype.Component;
import java.util.concurrent.TimeUnit;
@Component
public class Runner implements CommandLineRunner {
private final RabbitTemplate rabbitTemplate;
private final Receiver receiver;
public Runner(Receiver receiver, RabbitTemplate rabbitTemplate) {
this.receiver = receiver;
this.rabbitTemplate = rabbitTemplate;
}
@Override
public void run(String... args) throws Exception {
System.out.println("Sending message...");
rabbitTemplate.convertAndSend(TestAmqpApplication.topicExchangeName, "foo.bar.baz", "Hello from RabbitMQ!");
receiver.getLatch().await(10000, TimeUnit.MILLISECONDS);
}
}

Screenshot of the console output:

Compile your project with maven properly. Do Maven clean and install phases again.

If you are still facing issue, then do this steps:

• Also, invalidate cache for the project in Intellij.
  

• Last but not the least, create a fresh project and try again.