SpringBoot引入RabbitMQ（二）：关于无法消费消息的问题

来源：互联网收集：自由互联发布时间：2022-05-30

前文：SpringBoot引入RabbitMQ（一）：引入进SpringBoot中在前文中，就出现过一次无法发送消息的问题原因：SpringBoot在启动时，就会自动生成配置好的Queue、Exchange、Key等等，但是如果初次

前文：SpringBoot引入RabbitMQ（一）：引入进SpringBoot中

在前文中，就出现过一次无法发送消息的问题

原因：SpringBoot在启动时，就会自动生成配置好的Queue、Exchange、Key等等，但是如果初次启动时只有生产者或者消费者的情况下，并不会建立他们，所以发送消息失败。

解决：生产者、消费者都配置好之后，逐一启动即可自动生成，然后就可以正常发送消息了

现在生产者、消费者分开放在两个Demo中，再模拟一下收发消息

生产者：

原项目做生产者，具体搭建方法参考上文

OutSendMessageDTO

package com.zyuan.boot.rabbitmq.message.dto;


@Data
public class OutSendMessageDTO implements Serializable {

    private static final long serialVersionUID = 1L;

    private Long id;

    private String messageInfo;

}

MqConstant

public class MqConstant {public static final String OUT_SEND_MESSAGE_QUEUE = "outSendMessageQueue";
    public static final String OUT_SEND_MESSAGE_EXCHANGE = "outSendMessageExchange";
    public static final String OUT_SEND_MESSAGE_KEY = "outSendMessageKey";
}

OutSendMessageProducer

import com.zyuan.boot.rabbitmq.message.constant.MqConstant;
import com.zyuan.boot.rabbitmq.message.dto.OutSendMessageDTO;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;

@Component
public class OutSendMessageProducer {

    @Autowired
    private RabbitTemplate rabbitTemplate;

    public void sendOutMessage(OutSendMessageDTO outSendMessageDTO) {
        System.out.println("外发了一条消息");
        try {
            rabbitTemplate.convertAndSend(MqConstant.OUT_SEND_MESSAGE_EXCHANGE, MqConstant.OUT_SEND_MESSAGE_KEY, outSendMessageDTO);
            System.out.println("外发消息成功");
        } catch (Exception e) {
            System.out.println("外发消息失败");
            e.printStackTrace();
        }
    }

}

测试类：

@SpringBootTest
@RunWith(SpringRunner.class)
public class RabbitMqTest {
    @Autowired
    private OutSendMessageProducer outSendMessageProducer;

    @Test
    public void sendOutMessage() {
        OutSendMessageDTO outSendMessageDTO = new OutSendMessageDTO();
        outSendMessageDTO.setId(9999999L);
        outSendMessageDTO.setMessageInfo("这是外发的消息");
        outSendMessageProducer.sendOutMessage(outSendMessageDTO);
    }
}

消费者：

将OutSendMessageDTO、MqConstant复制过来

OutSendMessageConsumer

import com.rabbitmq.client.Channel;
import com.zyuan.boot.rabbitmqconsum.message.constant.MqConstant;
import com.zyuan.boot.rabbitmqconsum.message.dto.OutSendMessageDTO;
import org.springframework.amqp.core.Message;
import org.springframework.amqp.rabbit.annotation.*;
import org.springframework.messaging.handler.annotation.Payload;
import org.springframework.stereotype.Component;

import java.io.IOException;

@Component
public class OutSendMessageConsumer {

    @RabbitListener(
            bindings = {
                    @QueueBinding(
                            value = @Queue(value = MqConstant.OUT_SEND_MESSAGE_QUEUE),
                            exchange = @Exchange(value = MqConstant.OUT_SEND_MESSAGE_EXCHANGE),
                            key = MqConstant.OUT_SEND_MESSAGE_KEY
                    )
            }
    )
    public void consumeFirstMessage(@Payload OutSendMessageDTO outSendMessageDTO, Channel channel, Message message) {
        System.out.println("消费到了外发的信息:" + outSendMessageDTO.toString());
        try {
            channel.basicAck(message.getMessageProperties().getDeliveryTag(), false);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

}