流程

1.声明exchange、queue、RoutingKey
2. 在hotel-admin中进行增删改（SQL），完成消息发送
3. 在hotel-demo中完成消息监听，并更新elasticsearch数据
4. 测试同步

1.引入依赖

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

我这里的mq是挂在了docker上，虚拟机地址是192.168.116.128。到时候这个根据自己的项目改就行

 spring: rabbitmq:host: 192.168.116.128 # 主机名port: 5672 # 端口virtual-host: / # 虚拟主机username: itcast # 用户名password: 123321 # 密码

2.声明交换机、队列和绑定关系

package cn.itcast.hotel.constants;public class MqConstants {/*** 交换机*/public final static String HOTEL_EXCHANGE = "hotel.topic";/*** 监听新增和修改的队列*/public final static String HOTEL_INSERT_QUEUE = "hotel.insert.queue";/*** 监听删除的队列*/public final static String HOTEL_DELETE_QUEUE = "hotel.delete.queue";/*** 新增或修改的RoutingKey*/public final static String HOTEL_INSERT_KEY = "hotel.insert";/*** 删除的RoutingKey*/public final static String HOTEL_DELETE_KEY = "hotel.delete";
}

在hotel-demo中，定义配置类，声明队列、交换机：

package cn.itcast.hotel.config;import cn.itcast.hotel.constants.MqConstants;
import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.Queue;
import org.springframework.amqp.core.TopicExchange;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;@Configuration
public class MqConfig {// 定义交换机@Beanpublic TopicExchange topicExchange(){return new TopicExchange(MqConstants.HOTEL_EXCHANGE,true,false);}// 定义队列@Beanpublic Queue insertQueue(){return new Queue(MqConstants.HOTEL_INSERT_QUEUE,true);}@Beanpublic Queue deleteQueue(){return new Queue(MqConstants.HOTEL_DELETE_QUEUE,true);}// 定义绑定关系@Beanpublic Binding insertQueueBinding(){return BindingBuilder.bind(insertQueue()).to(topicExchange()).with(MqConstants.HOTEL_INSERT_KEY);}@Beanpublic Binding deleteQueueBinding(){return BindingBuilder.bind(deleteQueue()).to(topicExchange()).with(MqConstants.HOTEL_DELETE_KEY);}
}

3.发送MQ消息

在hotel-admin中的增、删、改业务中分别发送MQ消息,具体怎么添加根据：

    // 新增@PostMappingpublic void saveHotel(){//数据库新增操作rabbitTemplate.convertAndSend(MqConstants.HOTEL_EXCHANGE,MqConstants.HOTEL_INSERT_KEY,hotel.getId());}// 更新@PutMapping()public void updateById(){//数据库修改操作rabbitTemplate.convertAndSend(MqConstants.HOTEL_EXCHANGE,MqConstants.HOTEL_INSERT_KEY,hotel.getId());}// 删除@DeleteMapping("/{id}")public void deleteById() {// 数据库删除操作rabbitTemplate.convertAndSend(MqConstants.HOTEL_EXCHANGE,MqConstants.HOTEL_DELETE_KEY,id);}

4.监听MQ消息

接收MQ消息

hotel-demo接收到MQ消息要做的事情包括：

• 新增消息：根据传递的hotel的id查询hotel信息，然后新增一条数据到索引库
• 删除消息：根据传递的hotel的id删除索引库中的一条数据

1）首先在hotel-demo的cn.itcast.hotel.service包下的IHotelService中新增新增、删除业务

void deleteById(Long id);void insertById(Long id);

2）给hotel-demo中的cn.itcast.hotel.service.impl包下的HotelService中实现业务：

@Override
public void deleteById(Long id) {try {// 1.准备RequestDeleteRequest request = new DeleteRequest("hotel", id.toString());// 2.发送请求client.delete(request, RequestOptions.DEFAULT);} catch (IOException e) {throw new RuntimeException(e);}
}@Override
public void insertById(Long id) {try {// 0.根据id查询酒店数据Hotel hotel = getById(id);// 转换为文档类型HotelDoc hotelDoc = new HotelDoc(hotel);// 1.准备Request对象IndexRequest request = new IndexRequest("hotel").id(hotel.getId().toString());// 2.准备Json文档request.source(JSON.toJSONString(hotelDoc), XContentType.JSON);// 3.发送请求client.index(request, RequestOptions.DEFAULT);} catch (IOException e) {throw new RuntimeException(e);}
}

编写监听类

package cn.itcast.hotel.mq;import cn.itcast.hotel.constants.MqConstants;
import cn.itcast.hotel.service.IHotelService;
import org.springframework.amqp.rabbit.annotation.RabbitListener;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;@Component
public class HotelListener {// 专门用于消息监听的类@Autowiredprivate IHotelService hotelService;@RabbitListener(queues = MqConstants.HOTEL_INSERT_QUEUE)public void listenHotelInsertOrUpdate(Long id){hotelService.insertById(id);}@RabbitListener(queues = MqConstants.HOTEL_DELETE_QUEUE)public void listenHotelDelete(Long id){hotelService.deleteById(id);}
}