Spring boot RabbitMq 实现分布式事务

分布式事务：

• 指事务的操作位于不同的节点上，需要保证事务的ACID特性。
• eg: 下单场景下，库存和订单如果不在同一节点上，就涉及分布式事务

大致思路流程：

测试表：

代码：

死信交互机

import org.springframework.amqp.core.Binding;
import org.springframework.amqp.core.BindingBuilder;
import org.springframework.amqp.core.FanoutExchange;
import org.springframework.amqp.core.Queue;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

/**
 * @author xiaoshu
 * @description
 * @date 2022年03月19日 16:53
 */
@Configuration
public class DeadMq {

    @Bean
    public FanoutExchange fanoutDeadExchange(){
        return new FanoutExchange("fanout_dead_exchange");
    }

    @Bean
    public Queue deadQueue(){
        return new Queue("fanout_dead_order_queue");
    }

    @Bean
    public Binding deadBind(){
        return BindingBuilder.bind(deadQueue()).to(fanoutDeadExchange());
    }

}

声明订单交换机，订单队列 -> 死信交换机

import org.springframework.amqp.core.*;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import java.util.HashMap;
import java.util.Map;

/**
 * @Description MQ分布书事务，消息可靠生产
 * @Author Hexiaoshu
 * @Date 2021/7/10
 * @modify
 */
@Configuration
public class TransactionalRabbitMqConfig {
    /**
     * 发布订阅型，order交互机
     * @return FanoutExchange
     */
    @Bean
    public FanoutExchange transactionFanoutExchange(){
        return new FanoutExchange("fanout_transaction_order_exchange");
    }

    /**
     * 绑定订单交换机
     * @return Queue
     */
    @Bean
    public Queue transactionOrderQueue(){
        Map<String,Object> args = new HashMap<>();
        //args.put("x-message-ttl",10000);//过期时间int 类型
        //绑定死信交换机
        //args.put("x-max-length",5);//最大长度5条，超过进入死信队列
        args.put("x-dead-letter-exchange","fanout_dead_exchange");//指定死信交换机
        //args.put("x-dead-letter-routing-key","");//fanout 不用配置
        return new Queue("fanout_transaction_order_queue",true,false,false,args);
    }

    @Bean
    public Binding fanoutOrderBinding(){
        return BindingBuilder.bind(transactionOrderQueue()).to(transactionFanoutExchange());
    }
}

订单服务：推送订单-》MQ， 处理 -死信订单

import com.model.MyOrder;
import com.rabbitmq.client.Channel;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.RabbitHandler;
import org.springframework.amqp.rabbit.annotation.RabbitListener;

/**
 * @Description
 * @Author Hexiaoshu
 * @Date 2021/7/3
 * @modify
 */
@RabbitListener(queues = {"fanout_dead_order_queue"})
public interface OrderService {

    /**
     * 分布式事务 订单处理示例
     * @param myOrder
     */
    void transactionOrder(MyOrder myOrder);

    /**
     * 死信，问题订单处理
     * @param meeage
     * @param channel
     * @param message
     */
    @RabbitHandler
    void deadOrderHandler(String meeage, Channel channel, Message message);
}

	/**
     * TODO 这里加事务是，rabbitTemplate.convertAndSend(),这个方法在消息推送配置上可能报错，不会触发消息投递确认。
     */
    @Override
    @Transactional(rollbackFor = Exception.class)
    public void transactionOrder(MyOrder myOrder) {
        String exchangeName="fanout_transaction_order_exchange";
        MyOrderTmr curTmrOrder = new MyOrderTmr().setOrderId(myOrder.getOrderId()).setCreateTime(new Date()).setStatus(0);
        //添加订单
        int orderFlag = orderMapper.insert(myOrder);
        if (orderFlag>0){
            //设置订单MQ消息，冗余表；表示订单消息处理状态; status 0，默认未投递成功 ，1投递成功。 2产品服务，库存数量扣减成功
            int orderTmrFlag = orderTmrMapper.insert(curTmrOrder);
            if (orderTmrFlag>0){
                //投递消息到交换机
                rabbitTemplate.convertAndSend(exchangeName,"", JsonUtil.toStr(myOrder),new CorrelationData(String.valueOf(myOrder.getOrderId())));
            }
        }
    }

    @Override
    public void deadOrderHandler(String msg, Channel channel, Message message) {
        try {
            System.out.println("处理失败消息");
            System.out.println("消息内容："+msg);
            MyOrder order = JsonUtil.toObj(msg, MyOrder.class);
            orderMapper.updateByPrimaryKeySelective(order.setStatus(2));
            System.out.println("修改订单状态：2");
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);
        } catch (Exception e) {
            //处理异常，拒绝确认消息, 推送到死信交换机
            try {
                System.out.println("处理失败,拒绝消息");
                channel.basicNack(message.getMessageProperties().getDeliveryTag(),
                        false, false);
            } catch (IOException ex) {
                ex.printStackTrace();
            }
            System.err.println("get msg1 failed msg = "+msg);
            e.printStackTrace();
        }
    }

    /**
     * 订单消息投递确认，投递成功修改消息冗余状态
     * 分布式订单业务例子， 订单服务 -> RabbitMq (Exchange) -> 订单配送服务消费订单
     */
    @PostConstruct
    public void regCallBack(){
        rabbitTemplate.setConfirmCallback((correlationData, ack, cause) -> {
            System.out.println("cause:"+cause);
            assert correlationData != null;
            String orderId = correlationData.getId();
            //ack 为true代表收到消息
            if (!ack){
                System.out.println("MQ队列应答--失败，OrderId:"+orderId+",删除订单相关数据");
                orderMapper.deleteByPrimaryKey(new MyOrder().setOrderId(Long.parseLong(orderId)));
                orderTmrMapper.deleteByPrimaryKey(new MyOrderTmr().setOrderId(Long.parseLong(orderId)));
                return;
            }
            try {
                System.out.println("MQ队列应答--成功, 修改订单冗余状态 status=1，OrderId:"+orderId);
                //修改冗余消息状态,确认收到消息
                orderTmrMapper.updateByPrimaryKeySelective(new MyOrderTmr().setOrderId(Long.parseLong(orderId)).setStatus(1));
            }catch (Exception ex){
                System.out.println("本地消息出现异常"+ex.getMessage());
            }
        });
    }

另一节点库存服务：

import com.rabbitmq.client.Channel;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.RabbitHandler;
import org.springframework.amqp.rabbit.annotation.RabbitListener;

/**
 * @Description 订单消息接收
 * @Author Hexiaoshu
 * @Date 2021/7/11
 * @modify
 */
@RabbitListener(queues = {"fanout_transaction_order_queue"})
public interface TransactionalOrderConsumer {

    @RabbitHandler
    void orderHandler(String meeage, Channel channel, Message message);

}

import com.consumer.TransactionalOrderConsumer;
import com.mapper.ProductMapper;
import com.model.MyOrder;
import com.model.Product;
import com.rabbitmq.client.Channel;
import com.util.JsonUtil;
import org.springframework.amqp.core.Message;
import org.springframework.stereotype.Service;
import javax.annotation.Resource;
import java.io.IOException;

/**
 * @Description
 * @Author Hexiaoshu
 * @Date 2021/7/11
 * @modify
 */
@Service("transactionalOrderConsumer")
public class TransactionalOrderConsumerImpl implements TransactionalOrderConsumer {

    @Resource
    ProductMapper productMapper;

    /**
     * 处理派送订单
     */
    @Override
    public void orderHandler(String msg, Channel channel, Message message) {
        //处理状态，默认成功，false
        boolean handlerFlag=false;
        long msgTag = message.getMessageProperties().getDeliveryTag();
        try {
            //确认消息处理，返回ack
            System.out.println("消息内容："+msg);
            //报错，死信测试
            //int i=1/0;
            MyOrder order = JsonUtil.toObj(msg, MyOrder.class);
            Product curProduct = productMapper.selectByPrimaryKey( new Product().setId(order.getProductId()));
            //修改产品数量
            Product product1 = curProduct.setCount(curProduct.getCount()-1);
            productMapper.updateByPrimaryKey(product1);
            System.out.println("产品数量修改成功："+product1);
        } catch (Exception e) {
            handlerFlag=true;
            e.printStackTrace();
        }finally {
            if (handlerFlag){
                //确认消息
                toDo(channel, msgTag);
            }else {
                //拒绝消息
                toReject(channel, msgTag);
            }
        }
    }

    /**
     * 拒绝消息
     * @param channel 通道
     * @param msgTag  消息标识
     */
    private void toReject(Channel channel,Long msgTag){
        try {
            channel.basicNack(msgTag, false,false);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    /**
     * 确认消息
     * @param channel 通道
     * @param msgTag  消息标识
     */
    private void toDo(Channel channel,Long msgTag){
        try {
            channel.basicAck(msgTag, false);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}

测试入口

@RestController
public class OrderController {
    @Resource
    private OrderService orderService;

    @GetMapping("/sendOrder")
    public String order(){
        String orderName="购买白象方便面";
        long orderId = SnowflakeIdWorker.id();
        long productId = 1L;
        MyOrder curMyOrder = new MyOrder().setOrderId(orderId).setProductId(productId).setOrderName(orderName).setCreateTime(new Date());
        orderService.transactionOrder(curMyOrder);
        return "订单生产成功";
    }

}