SpringBoot+RabbitMQ （保证消息100%投递成功并被消费）

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一、先扔一张图

• 简略介绍163邮箱授权码的获取

• 编写发送邮件工具类

• 编写RabbitMQ配置文件

• 生产者发起调用

• 消费者发送邮件

• 定时任务定时拉取投递失败的消息, 重新投递

• 各种异常情况的测试验证

org.springframework.boot
spring-boot-starter-amqp



org.springframework.boot
spring-boot-starter-mail

# rabbitmq
spring.rabbitmq.host=localhost
spring.rabbitmq.port=5672
spring.rabbitmq.username=guest
spring.rabbitmq.password=guest
# 开启confirms回调 P -> Exchange
spring.rabbitmq.publisher-confirms=true
# 开启returnedMessage回调 Exchange -> Queue
spring.rabbitmq.publisher-returns=true
# 设置手动确认(ack) Queue -> C
spring.rabbitmq.listener.simple.acknowledge-mode=manual
spring.rabbitmq.listener.simple.prefetch=100

# mail
spring.mail.host=smtp.163.com
spring.mail.username=18621142249@163.com
spring.mail.password=123456wangzai
spring.mail.from=18621142249@163.com
spring.mail.properties.mail.smtp.auth=true
spring.mail.properties.mail.smtp.starttls.enable=true
spring.mail.properties.mail.smtp.starttls.required=true

CREATE TABLE `msg_log` (
  `msg_id` varchar(255) NOT NULL DEFAULT '' COMMENT '消息唯一标识',
  `msg` text COMMENT '消息体, json格式化',
  `exchange` varchar(255) NOT NULL DEFAULT '' COMMENT '交换机',
  `routing_key` varchar(255) NOT NULL DEFAULT '' COMMENT '路由键',
  `status` int(11) NOT NULL DEFAULT '0' COMMENT '状态: 0投递中 1投递成功 2投递失败 3已消费',
  `try_count` int(11) NOT NULL DEFAULT '0' COMMENT '重试次数',
  `next_try_time` datetime DEFAULT NULL COMMENT '下一次重试时间',
  `create_time` datetime DEFAULT NULL COMMENT '创建时间',
  `update_time` datetime DEFAULT NULL COMMENT '更新时间',
  PRIMARY KEY (`msg_id`),
  UNIQUE KEY `unq_msg_id` (`msg_id`) USING BTREE
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COMMENT='消息投递日志';

@Component
@Slf4j
public class MailUtil {

    @Value("${spring.mail.from}")
    private String from;

    @Autowired
    private JavaMailSender mailSender;

    /**
     * 发送简单邮件
     *
     * @param mail
     */
    public boolean send(Mail mail) {
        String to = mail.getTo();// 目标邮箱
        String title = mail.getTitle();// 邮件标题
        String content = mail.getContent();// 邮件正文

        SimpleMailMessage message = new SimpleMailMessage();
        message.setFrom(from);
        message.setTo(to);
        message.setSubject(title);
        message.setText(content);

        try {
            mailSender.send(message);
            log.info("邮件发送成功");
            return true;
        } catch (MailException e) {
            log.error("邮件发送失败, to: {}, title: {}", to, title, e);
            return false;
        }
    }

}

@Configuration
@Slf4j
public class RabbitConfig {

    @Autowired
    private CachingConnectionFactory connectionFactory;

    @Autowired
    private MsgLogService msgLogService;

    @Bean
    public RabbitTemplate rabbitTemplate() {
        RabbitTemplate rabbitTemplate = new RabbitTemplate(connectionFactory);
        rabbitTemplate.setMessageConverter(converter());

        // 消息是否成功发送到Exchange
        rabbitTemplate.setConfirmCallback((correlationData, ack, cause) -> {
            if (ack) {
                log.info("消息成功发送到Exchange");
                String msgId = correlationData.getId();
                msgLogService.updateStatus(msgId, Constant.MsgLogStatus.DELIVER_SUCCESS);
            } else {
                log.info("消息发送到Exchange失败, {}, cause: {}", correlationData, cause);
            }
        });

        // 触发setReturnCallback回调必须设置mandatory=true, 否则Exchange没有找到Queue就会丢弃掉消息, 而不会触发回调
        rabbitTemplate.setMandatory(true);
        // 消息是否从Exchange路由到Queue, 注意: 这是一个失败回调, 只有消息从Exchange路由到Queue失败才会回调这个方法
        rabbitTemplate.setReturnCallback((message, replyCode, replyText, exchange, routingKey) -> {
            log.info("消息从Exchange路由到Queue失败: exchange: {}, route: {}, replyCode: {}, replyText: {}, message: {}", exchange, routingKey, replyCode, replyText, message);
        });

        return rabbitTemplate;
    }

    @Bean
    public Jackson2JsonMessageConverter converter() {
        return new Jackson2JsonMessageConverter();
    }

    // 发送邮件
    public static final String MAIL_QUEUE_NAME = "mail.queue";
    public static final String MAIL_EXCHANGE_NAME = "mail.exchange";
    public static final String MAIL_ROUTING_KEY_NAME = "mail.routing.key";

    @Bean
    public Queue mailQueue() {
        return new Queue(MAIL_QUEUE_NAME, true);
    }

    @Bean
    public DirectExchange mailExchange() {
        return new DirectExchange(MAIL_EXCHANGE_NAME, true, false);
    }

    @Bean
    public Binding mailBinding() {
        return BindingBuilder.bind(mailQueue()).to(mailExchange()).with(MAIL_ROUTING_KEY_NAME);
    }

}

@Service
public class TestServiceImpl implements TestService {

    @Autowired
    private MsgLogMapper msgLogMapper;

    @Autowired
    private RabbitTemplate rabbitTemplate;

    @Override
    public ServerResponse send(Mail mail) {
        String msgId = RandomUtil.UUID32();
        mail.setMsgId(msgId);

        MsgLog msgLog = new MsgLog(msgId, mail, RabbitConfig.MAIL_EXCHANGE_NAME, RabbitConfig.MAIL_ROUTING_KEY_NAME);
        msgLogMapper.insert(msgLog);// 消息入库

        CorrelationData correlationData = new CorrelationData(msgId);
        rabbitTemplate.convertAndSend(RabbitConfig.MAIL_EXCHANGE_NAME, RabbitConfig.MAIL_ROUTING_KEY_NAME, MessageHelper.objToMsg(mail), correlationData);// 发送消息

        return ServerResponse.success(ResponseCode.MAIL_SEND_SUCCESS.getMsg());
    }

}

@Component
@Slf4j
public class MailConsumer {

    @Autowired
    private MsgLogService msgLogService;

    @Autowired
    private MailUtil mailUtil;

    @RabbitListener(queues = RabbitConfig.MAIL_QUEUE_NAME)
    public void consume(Message message, Channel channel) throws IOException {
        Mail mail = MessageHelper.msgToObj(message, Mail.class);
        log.info("收到消息: {}", mail.toString());

        String msgId = mail.getMsgId();

        MsgLog msgLog = msgLogService.selectByMsgId(msgId);
        if (null == msgLog || msgLog.getStatus().equals(Constant.MsgLogStatus.CONSUMED_SUCCESS)) {// 消费幂等性
            log.info("重复消费, msgId: {}", msgId);
            return;
        }

        MessageProperties properties = message.getMessageProperties();
        long tag = properties.getDeliveryTag();

        boolean success = mailUtil.send(mail);
        if (success) {
            msgLogService.updateStatus(msgId, Constant.MsgLogStatus.CONSUMED_SUCCESS);
            channel.basicAck(tag, false);// 消费确认
        } else {
            channel.basicNack(tag, false, true);
        }
    }

}

@Component
@Slf4j
public class ResendMsg {

    @Autowired
    private MsgLogService msgLogService;

    @Autowired
    private RabbitTemplate rabbitTemplate;

    // 最大投递次数
    private static final int MAX_TRY_COUNT = 3;

    /**
     * 每30s拉取投递失败的消息, 重新投递
     */
    @Scheduled(cron = "0/30 * * * * ?")
    public void resend() {
        log.info("开始执行定时任务(重新投递消息)");

        ListmsgLogs = msgLogService.selectTimeoutMsg();
        msgLogs.forEach(msgLog -> {
            String msgId = msgLog.getMsgId();
            if (msgLog.getTryCount() >= MAX_TRY_COUNT) {
                msgLogService.updateStatus(msgId, Constant.MsgLogStatus.DELIVER_FAIL);
                log.info("超过最大重试次数, 消息投递失败, msgId: {}", msgId);
            } else {
                msgLogService.updateTryCount(msgId, msgLog.getNextTryTime());// 投递次数+1

                CorrelationData correlationData = new CorrelationData(msgId);
                rabbitTemplate.convertAndSend(msgLog.getExchange(), msgLog.getRoutingKey(), MessageHelper.objToMsg(msgLog.getMsg()), correlationData);// 重新投递

                log.info("第 " + (msgLog.getTryCount() + 1) + " 次重新投递消息");
            }
        });

        log.info("定时任务执行结束(重新投递消息)");
    }

}

七、拓展: 使用动态代理实现消费端幂等性验证和消费确认(ack)

八、总结

推荐阅读：

为什么MySQL不推荐使用uuid或者雪花id作为主键？

再见，Visio！

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