How to read the messages from rabbitmq other than using listener configuration? - spring

Question

I am attempting to implement Spring Boot API to fetch the RabbitMQ Messages on demand for asynchronous cart notifications in UI. I already have a working implementation with the help of the Registered listener method. But I am looking for an alternative with or without spring.
#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;
}
}
Main Class with Reciever Configuration:
#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();
}
}
My Current Implementation Reference is from: https://spring.io/guides/gs/messaging-rabbitmq/

Answer 1

See RabbitTemplate API:
/**
* Receive a message if there is one from a specific queue. Returns immediately,
* possibly with a null value.
*
* #param queueName the name of the queue to poll
* #return a message or null if there is none waiting
* #throws AmqpException if there is a problem
*/
#Nullable
Message receive(String queueName) throws AmqpException;
/**
* Receive a message if there is one from a specific queue and convert it to a Java
* object. Returns immediately, possibly with a null value.
*
* #param queueName the name of the queue to poll
* #return a message or null if there is none waiting
* #throws AmqpException if there is a problem
*/
#Nullable
Object receiveAndConvert(String queueName) throws AmqpException;
And respective docs: https://docs.spring.io/spring-amqp/reference/html/#polling-consumer