SpringBoot集成RabbitMQ的四种交换机（Direct、Topic、Fanout、Headers）

以下是四种 RabbitMQ 交换机类型（Direct、Topic、Fanout、Headers）的详细实例代码，展示如何分别实现并使用它们。

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1. Direct Exchange（直连交换机）

Direct Exchange 将消息根据路由键（Routing Key）发送到指定的队列。

配置代码

@Configuration
public class DirectExchangeConfig {
​
    public static final String DIRECT_EXCHANGE = "direct_exchange";
    public static final String DIRECT_QUEUE = "direct_queue";
    public static final String DIRECT_ROUTING_KEY = "direct_key";
​
    @Bean
    public DirectExchange directExchange() {
        return new DirectExchange(DIRECT_EXCHANGE);
    }
​
    @Bean
    public Queue directQueue() {
        return new Queue(DIRECT_QUEUE);
    }
​
    @Bean
    public Binding directBinding(Queue directQueue, DirectExchange directExchange) {
        return BindingBuilder.bind(directQueue).to(directExchange).with(DIRECT_ROUTING_KEY);
    }
}

发送消息

@Component
public class DirectMessageProducer {
    @Autowired
    private RabbitTemplate rabbitTemplate;
​
    public void send(String message) {
        rabbitTemplate.convertAndSend("direct_exchange", "direct_key", message);
        System.out.println("Direct Message Sent: " + message);
    }
}

接收消息

@Component
public class DirectMessageConsumer {
    @RabbitListener(queues = "direct_queue")
    public void receive(String message) {
        System.out.println("Direct Message Received: " + message);
    }
}

2. Topic Exchange（主题交换机）

Topic Exchange 根据通配符匹配路由键发送消息。

配置代码

@Configuration
public class TopicExchangeConfig {
​
    public static final String TOPIC_EXCHANGE = "topic_exchange";
    public static final String TOPIC_QUEUE = "topic_queue";
    public static final String ROUTING_KEY_PATTERN = "topic.#";
​
    @Bean
    public TopicExchange topicExchange() {
        return new TopicExchange(TOPIC_EXCHANGE);
    }
​
    @Bean
    public Queue topicQueue() {
        return new Queue(TOPIC_QUEUE);
    }
​
    @Bean
    public Binding topicBinding(Queue topicQueue, TopicExchange topicExchange) {
        return BindingBuilder.bind(topicQueue).to(topicExchange).with(ROUTING_KEY_PATTERN);
    }
}

发送消息

@Component
public class TopicMessageProducer {
    @Autowired
    private RabbitTemplate rabbitTemplate;
​
    public void send(String message, String routingKey) {
        rabbitTemplate.convertAndSend("topic_exchange", routingKey, message);
        System.out.println("Topic Message Sent: " + message + " with Routing Key: " + routingKey);
    }
}

接收消息

@Component
public class TopicMessageConsumer {
    @RabbitListener(queues = "topic_queue")
    public void receive(String message) {
        System.out.println("Topic Message Received: " + message);
    }
}

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3. Fanout Exchange（广播交换机）

Fanout Exchange 将消息广播到所有绑定的队列，无需路由键。

配置代码

@Configuration
public class FanoutExchangeConfig {
​
    public static final String FANOUT_EXCHANGE = "fanout_exchange";
    public static final String FANOUT_QUEUE_1 = "fanout_queue_1";
    public static final String FANOUT_QUEUE_2 = "fanout_queue_2";
​
    @Bean
    public FanoutExchange fanoutExchange() {
        return new FanoutExchange(FANOUT_EXCHANGE);
    }
​
    @Bean
    public Queue fanoutQueue1() {
        return new Queue(FANOUT_QUEUE_1);
    }
​
    @Bean
    public Queue fanoutQueue2() {
        return new Queue(FANOUT_QUEUE_2);
    }
​
    @Bean
    public Binding fanoutBinding1(Queue fanoutQueue1, FanoutExchange fanoutExchange) {
        return BindingBuilder.bind(fanoutQueue1).to(fanoutExchange);
    }
​
    @Bean
    public Binding fanoutBinding2(Queue fanoutQueue2, FanoutExchange fanoutExchange) {
        return BindingBuilder.bind(fanoutQueue2).to(fanoutExchange);
    }
}

发送消息

@Component
public class FanoutMessageProducer {
    @Autowired
    private RabbitTemplate rabbitTemplate;
​
    public void send(String message) {
        rabbitTemplate.convertAndSend("fanout_exchange", "", message);
        System.out.println("Fanout Message Sent: " + message);
    }
}

接收消息

@Component
public class FanoutMessageConsumer1 {
    @RabbitListener(queues = "fanout_queue_1")
    public void receive(String message) {
        System.out.println("Fanout Queue 1 Received: " + message);
    }
}
​
@Component
public class FanoutMessageConsumer2 {
    @RabbitListener(queues = "fanout_queue_2")
    public void receive(String message) {
        System.out.println("Fanout Queue 2 Received: " + message);
    }
}

4. Headers Exchange（头交换机）

Headers Exchange 根据消息头中的键值对匹配发送消息。

配置代码

@Configuration
public class HeadersExchangeConfig {
​
    public static final String HEADERS_EXCHANGE = "headers_exchange";
    public static final String HEADERS_QUEUE = "headers_queue";
​
    @Bean
    public HeadersExchange headersExchange() {
        return new HeadersExchange(HEADERS_EXCHANGE);
    }
​
    @Bean
    public Queue headersQueue() {
        return new Queue(HEADERS_QUEUE);
    }
​
    @Bean
    public Binding headersBinding(Queue headersQueue, HeadersExchange headersExchange) {
        return BindingBuilder.bind(headersQueue).to(headersExchange).where("header_key").matches("header_value");
    }
}

发送消息

@Component
public class HeadersMessageProducer {
    @Autowired
    private RabbitTemplate rabbitTemplate;
​
    public void send(String message) {
        MessageProperties messageProperties = new MessageProperties();
        messageProperties.setHeader("header_key", "header_value");
        Message amqpMessage = new Message(message.getBytes(), messageProperties);
        rabbitTemplate.convertAndSend("headers_exchange", "", amqpMessage);
        System.out.println("Headers Message Sent: " + message);
    }
}

接收消息

@Component
public class HeadersMessageConsumer {
    @RabbitListener(queues = "headers_queue")
    public void receive(String message) {
        System.out.println("Headers Message Received: " + message);
    }
}

总结

交换机类型	匹配机制	示例用途
Direct	精确匹配路由键（Routing Key）。	点对点通信
Topic	通配符匹配路由键（* 单词，# 多单词）。	广义主题订阅
Fanout	广播消息到所有绑定的队列，无需路由键。	广播通知
Headers	根据消息头的键值对匹配。	高级过滤逻辑

根据你的实际场景，可以选择适合的交换机类型并配置！