RabbitMq的work&topic&fanout模式

1、异步处理：传统的注册成功，注册写入数据库，在发送邮箱，在发送短信，则返回注册成功，利用rabbitmq异步处理，直接写入数据库后返回注册成功，之后再去rabbitmq消费发送邮箱和短信。

2、双11狂欢节，传统做法应用解耦：订单系统访问库存系统，这种做法有缺点，库存系统出现故障，订单会丢失，可以采用rabbitmq，订单系统下单成功，写入rabbitmq返回下单成功，订阅模式，库存系统去rabbitmq消费。

3、流量削峰，秒杀活动中，人流量太大，存入rabbitmq：可以控制人数，订单超过值，直接丢弃,秒杀失败，缓解短时间流量太大压垮应用。

首先引入maven包，集成springboot在代码配置文件加上：

  
            org.springframework.boot
            spring-boot-starter-amqp
        

# ----- RabbitMq -------- #
spring.rabbitmq.virtual-host=/
spring.rabbitmq.host=localhost
spring.rabbitmq.port=5672
spring.rabbitmq.username=admin
spring.rabbitmq.password=admin

@Component
public class RabbitQuestConfig {

    @Bean
    public Queue create(){
        return new Queue("work");
    }
}

接口里写上：

  @RequestMapping("/work")
    public void work() {
        String str = "work";
        for (int i = 0; i < 100; i++) {
            rabbitTemplate.convertAndSend("work", str);
        }
    }

@Component
@Slf4j
public class ConsumerRabbitMq {

    @Resource
    private RabbitMqMapper rabbitMqMapper;


    @RabbitListener(queues = "work")
    public void test(String message) {
        System.out.println("work消费成功1:" + message);
    }

    @RabbitListener(queues = "work")
    public void test2(String message) {
        System.out.println("work消费成功2:" + message);
    }
}

topic 是RabbitMQ中最灵活的一种方式，可以根据routing_key自由的绑定不同的队列

@Configuration
public class TopicRabbitConfig {

    final static String message = "topic_message";
    final static String messages = "topic_messages";

    @Bean
    public Queue topicMessage() {
        return new Queue(TopicRabbitConfig.message);
    }

    @Bean
    public Queue topicMessages() {
        return new Queue(TopicRabbitConfig.messages);
    }

    
    @Bean
    TopicExchange topicExchange() {
        return new TopicExchange("topicExchange");
    }

    
    @Bean
    Binding bindExchangeMessage(Queue topicMessage, TopicExchange topicExchange) {
        return BindingBuilder.bind(topicMessage).to(topicExchange).with("topic.message");
    }

    
    @Bean
    Binding bindExchangeMessages(Queue topicMessages, TopicExchange topicExchange) {
        return BindingBuilder.bind(topicMessages).to(topicExchange).with("topic.#");
    }
}

 
    @RequestMapping("/topic")
    public void topic() {
        for (int i = 0; i < 50; i++) {
            String topicMessage1 = "topicMessage1";
            rabbitTemplate.convertAndSend("topicExchange", "topic.message", topicMessage1);

            String topicMessage2 = "2topicMessage2";
            rabbitTemplate.convertAndSend("topicExchange", "topic.messages", topicMessage2);
        }
    }


//消费者：
@RabbitListener(queues = "topic_message")
    public void topicMessage1(String message) {
        System.out.println("topicMessage 消费成功只能消费 topicMessage1:" + message);
    }

    
    @RabbitListener(queues = "topic_messages")
    public void topicMessage2(String message) {
        System.out.println("topicMessages 消费 topicMessage1 & topicMessage2:" + message);
    }

@Configuration
public class FanoutRabbitConfig {

   @Bean
    public Queue aMessage(){
       return new Queue("a_message");
   }

    @Bean
    public Queue bMessage(){
        return new Queue("b_message");
    }

    @Bean
    FanoutExchange fanoutExchange(){
       return new FanoutExchange("fanoutExchange");
    }

    @Bean
    Binding bindingExchangeA(Queue aMessage,FanoutExchange fanoutExchange){
       return BindingBuilder.bind(aMessage).to(fanoutExchange);
    }

    @Bean
    Binding bindingExchangeB(Queue bMessage,FanoutExchange fanoutExchange){
        return BindingBuilder.bind(bMessage).to(fanoutExchange);
    }
}

生产者和消费者

 
    @RequestMapping("/fanout")
    public void fanout() {
        String fanout = "fanout";
        rabbitTemplate.convertAndSend("fanoutExchange", "", fanout);

    }


    
    @RabbitListener(queues = {"a_message"})
    public void fanoutA(String message) {
        System.out.println("fanout广播消费：" + message);
    }

    @RabbitListener(queues = {"b_message"})
    public void fanoutB(String message) {
        System.out.println("fanout广播消费：" + message);
    }

(完...)