件，通过RabbitMQ可以帮助我们实现异步、削峰的目的。

今天这篇，我们来看看Spring Boot是如何集成RabbitMQ，发送消息和消费消息的。同时我们介绍下死信队列。

集成RabbitMQ

集成RabbitMQ只需要如下几步即可

1、添加maven依赖

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

2、添加配置文件application.yaml

在application.yaml添加配置内容如下

spring:  rabbitmq:  host: 192.168.1.161           port: 5672  username: guest           password: guest           cache:  channel: size: 10  listener:  type: simple  simple:  acknowledge-mode: auto  concurrency: 5  default-requeue-rejected: true  max-concurrency: 100  retry:  enabled: true #                  initial-interval: 1000ms  max-attempts: 3 #                  max-interval: 1000ms  multiplier: 1                   stateless: true #          publisher-confirms: true</pre> 

注意：

这里最基本的配置只需要配置host,port,username和password四个属性即可

其他属性都有各自的含义，比如retry是用于配置重试策略的，acknowledge-mode是配置消息接收确认机制的。

3、编写配置类

编写RabbitConfig配置类，采用Java Configuration的方式配置RabbitTemplate、Exchange和Queue等信息，具体如下所示

package com.jackie.springbootdemo.config;  import org.springframework.amqp.core.*; import org.springframework.amqp.rabbit.config.SimpleRabbitListenerContainerFactory; import org.springframework.amqp.rabbit.connection.ConnectionFactory; import org.springframework.amqp.rabbit.core.RabbitTemplate; import org.springframework.amqp.support.converter.Jackson2JsonMessageConverter; import org.springframework.beans.factory.InitializingBean; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.beans.factory.annotation.Qualifier; import org.springframework.beans.factory.annotation.Value; import org.springframework.beans.factory.config.ConfigurableBeanFactory; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.context.annotation.Scope;  import java.util.HashMap; import java.util.Map;  @Configuration public class RabbitMQConfig implements InitializingBean {   @Autowired  SimpleRabbitListenerContainerFactory simpleRabbitListenerContainerFactory;      @Override  public void afterPropertiesSet() throws Exception {  simpleRabbitListenerContainerFactory.setMessageConverter(new Jackson2JsonMessageConverter());     }   @Bean("jackson2JsonMessageConverter")  public Jackson2JsonMessageConverter jackson2JsonMessageConverter(ConnectionFactory connectionFactory) {  return new Jackson2JsonMessageConverter();     }   @Bean("rabbitTemplate")  @Scope(ConfigurableBeanFactory.SCOPE_SINGLETON)  public RabbitTemplate rabbitTemplate(ConnectionFactory connectionFactory,                                          @Qualifier("jackson2JsonMessageConverter") Jackson2JsonMessageConverter jackson2JsonMessageConverter) {  RabbitTemplate template = new RabbitTemplate(connectionFactory