spring-amqp

Spring AMQP (RabbitMQ) - Quick Reference

Full Reference: See advanced.md for exchange types (topic, fanout), consumer patterns (multi-method, request-reply), error handling, DLQ processing, and testing.

Deep Knowledge: Use mcp__documentation__fetch_docs with technology: rabbitmq for comprehensive documentation.

Dependencies

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

Configuration

spring:
  rabbitmq:
    host: localhost
    port: 5672
    username: guest
    password: guest
    listener:
      simple:
        acknowledge-mode: manual
        concurrency: 3
        max-concurrency: 10
        prefetch: 10

Exchange, Queue, Binding Setup

@Configuration
public class RabbitMQConfig {

    public static final String EXCHANGE = "orders.exchange";
    public static final String QUEUE = "orders.queue";
    public static final String ROUTING_KEY = "orders.created";

    @Bean
    public DirectExchange ordersExchange() {
        return new DirectExchange(EXCHANGE);
    }

    @Bean
    public Queue ordersQueue() {
        return QueueBuilder.durable(QUEUE)
            .withArgument("x-dead-letter-exchange", "orders.dlx")
            .withArgument("x-dead-letter-routing-key", "dead")
            .build();
    }

    @Bean
    public Binding ordersBinding() {
        return BindingBuilder.bind(ordersQueue()).to(ordersExchange()).with(ROUTING_KEY);
    }

    @Bean
    public Jackson2JsonMessageConverter messageConverter() {
        return new Jackson2JsonMessageConverter();
    }
}

Producer

@Service
@RequiredArgsConstructor
public class OrderProducer {

    private final RabbitTemplate rabbitTemplate;

    public void sendOrder(OrderEvent event) {
        rabbitTemplate.convertAndSend(EXCHANGE, ROUTING_KEY, event);
    }

    public void sendWithHeaders(OrderEvent event, String correlationId) {
        rabbitTemplate.convertAndSend(EXCHANGE, ROUTING_KEY, event, message -> {
            message.getMessageProperties().setCorrelationId(correlationId);
            message.getMessageProperties().setDeliveryMode(MessageDeliveryMode.PERSISTENT);
            return message;
        });
    }
}

Consumer

@Service
public class OrderConsumer {

    @RabbitListener(queues = "orders.queue")
    public void consume(
            @Payload OrderEvent event,
            @Header(AmqpHeaders.DELIVERY_TAG) long deliveryTag,
            @Header(AmqpHeaders.CORRELATION_ID) String correlationId,
            Channel channel) throws IOException {

        try {
            processOrder(event);
            channel.basicAck(deliveryTag, false);
        } catch (Exception e) {
            channel.basicNack(deliveryTag, false, false); // Send to DLQ
        }
    }
}

Best Practices

Do	Don't
Use manual acknowledgment	Auto-ack without processing
Configure DLX/DLQ	Silently lose failed messages
Set message TTL	Keep messages forever
Use persistent delivery	Transient for important messages
Configure prefetch	Unbounded prefetch

When NOT to Use This Skill

• Raw RabbitMQ - Use rabbitmq skill for server configuration
• Kafka integration - Use spring-kafka skill
• Generic messaging patterns - Consult messaging-expert

Anti-Patterns

Anti-Pattern	Problem	Solution
Auto-ack without processing	Message loss	Use manual acknowledgment
No DLQ configured	Lost failed messages	Configure dead letter exchange
Unbounded prefetch	Memory issues	Set appropriate prefetch count
Blocking in listener	Thread exhaustion	Use async processing
No retry policy	Temporary failures cause loss	Configure retry with backoff

Quick Troubleshooting

Problem	Diagnostic	Fix
Connection refused	Check RabbitMQ running	Verify host/port
Message not consumed	Check queue binding	Verify routing key
Messages in DLQ	Check x-death header	Fix processing error
Consumer not starting	Check @RabbitListener	Verify queue exists
Serialization error	Check message type	Configure Jackson converter

Production Checklist

• Connection factory configured
• Manual acknowledgment mode
• DLX/DLQ configured
• Retry policy set
• Message converter configured
• Publisher confirms enabled
• Prefetch count optimized
• Error handler implemented
• Message TTL set
• Monitoring enabled

Reference Documentation

• Spring AMQP Reference