springboot整合rabbitMQ系列1 启动服务后便自动创建交换机，队列，绑定关系等

参考博文
SpringBoot整合rabbitMQ,启动服务便创建交换机和队列_rabbitmq配置类在启动时就创建-CSDN博客

启动服务不默认先创建队列的话，在启动消费者时候，消费者服务监听会找不到对应的队列而报错，启动失败

1 application.yml配置

server:
  port: 8021
spring:
  #给项目来个名字
  application:
    name: rabbitmq-test
  #配置rabbitMq 服务器
  rabbitmq:
    host: 127.0.0.1
    port: 5672
    username: need
    password: 123456
    #虚拟host 可以不设置,使用server默认host
    virtual-host: /testhost

2 交换机，队列，绑定等 配置类，核心两个方法拉到最后，其他方法就是正常的创建交换机，队列，绑定等，另外RabbitAdmin 加了@Lazy，解决循环依赖

import org.springframework.amqp.core.*;
import org.springframework.amqp.rabbit.connection.ConnectionFactory;
import org.springframework.amqp.rabbit.core.RabbitAdmin;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.context.annotation.Lazy;
import java.util.HashMap;
 
@Configuration
public class ExchangeQueueBindingConfig {
 
    //自动创建就是靠他
    //开启懒加载，不然会有循环依赖问题
    @Lazy
    @Autowired
    RabbitAdmin rabbitAdmin;
 
    //死信队列
    @Bean
    public Queue createShiXinQueue() {
        return new Queue("shixin_queue", true);
    }
 
    //死信交换机
    @Bean
    public DirectExchange createShiXinExchange() {
        return new DirectExchange("shixin_exchange", true, false);
    }
 
    //死信交换机 死信队列 绑定
    @Bean
    public Binding createShiXinBinding() {
        return BindingBuilder.bind(createShiXinQueue()).to(createShiXinExchange()).with("shixin");
    }
 
    //正常队列
    @Bean
    public Queue createZhengChangQueue() {
        HashMap<String, Object> map = new HashMap<String, Object>();
        map.put("x-dead-letter-exchange", "shixin_exchange");
        map.put("x-dead-letter-routing-key", "shixin");
        return new Queue("zhengchang_queue", true, false, false, map);
    }
 
    //正常交换机
    @Bean
    public TopicExchange createZhengChangExchange() {
        return new TopicExchange("zhengchang_exchange", true, false);
    }
 
    //正常交换机 正常队列 绑定
    @Bean
    public Binding createZhengChangBinding() {
        return BindingBuilder.bind(createZhengChangQueue()).to(createZhengChangExchange()).with("chongqing.#");
    }
 
    //创建初始化RabbitAdmin对象
    @Bean
    public RabbitAdmin rabbitAdmin(ConnectionFactory connectionFactory) {
        RabbitAdmin rabbitAdmin = new RabbitAdmin(connectionFactory);
        // 只有设置为 true，spring 才会加载 RabbitAdmin 这个类
        rabbitAdmin.setAutoStartup(true);
        return rabbitAdmin;
    }
 
    //创建交换机和对列
    @Bean
    public void createExchangeQueue() {
        //死信
        rabbitAdmin.declareExchange(createShiXinExchange());
        rabbitAdmin.declareQueue(createShiXinQueue());
        //正常
        rabbitAdmin.declareExchange(createZhengChangExchange());
        rabbitAdmin.declareQueue(createZhengChangQueue());
    }
}