SpringBoot+RabbitMQ 保证消息100%投递成功并被消费

image.png

本文主要是通过发送邮件来展示关于RabbitMQ很多方面的知识点, 如:
1.消息发送确认机制
2.消费确认机制
3.消息的重新投递
4.消费幂等性, 等等
二、实现思路
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 判定是否重复消费 发送邮件成功后修改状态
定时任务定时拉取状态为投递失败的消息, 进行重新投递

项目技术：springboot，RabbitMQ，javaMail，mysql， mybatisPlus
1.创建springboot项目 引入依赖

    4.0.0
    
        org.springframework.boot
        spring-boot-starter-parent
        2.3.4.RELEASE
         
    
    com.rabbitmail
    rabbit-mail-0921
    0.0.1-SNAPSHOT
    rabbit-mail-0921
    Demo project for Spring Boot

    
        1.8
    

    
        
            org.springframework.boot
            spring-boot-starter-web
        

        
            org.projectlombok
            lombok
        
        
            com.google.code.gson
            gson
        

        
        
            com.baomidou
            mybatis-plus-boot-starter
            3.2.0
        
        
            mysql
            mysql-connector-java
            runtime
        

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

        
            org.springframework.boot
            spring-boot-starter-test
            test
            
                
                    org.junit.vintage
                    junit-vintage-engine
                
            
        
        
            org.springframework.amqp
            spring-rabbit-test
            test
        


        
        
            org.apache.commons
            commons-lang3
            3.4
        
        




        
        
            com.google.guava
            guava
            26.0-jre
        
        
        
            joda-time
            joda-time
            2.10
        
        
            org.apache.commons
            commons-collections4
            4.1
        

    

    
        
            
                org.springframework.boot
                spring-boot-maven-plugin
            
        
    

2.application.properties

server.port=8888
spring.datasource.url = jdbc:mysql://127.0.0.1:3306/rabbit_mail?characterEncoding=utf8&allowMultiQueries=true&useSSL=false
spring.datasource.username = root
spring.datasource.password = root
spring.datasource.driver-class-name = com.mysql.jdbc.Driver
mybatis.mapperLocations = classpath:mapper/**/*.xml
##########################################################


##########################################################
# rabbitmq
spring.rabbitmq.host=127.0.0.1
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.qiye.aliyun.com
spring.mail.username = [email protected]
spring.mail.password= xxxxx
[email protected]
spring.mail.properties.mail.smtp.auth= true
spring.mail.properties.mail.smtp.starttls.enable= true
spring.mail.properties.mail.smtp.starttls.required= true
spring.mail.properties.mail.smtp.ssl.enable= true
spring.mail.default-encoding: utf-8

3.mysql表结构

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'

4.发送邮件util MailUtil

@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;
        }
    }
}

5.RabbitConfig

@Configuration
@Slf4j
public class RabbitConfig {
    @Autowired
    private CachingConnectionFactory connectionFactory;

    @Autowired
    private IMsgLogService 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();
    }

    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);
    }
}

6.单元测试 测试发送消息

@Autowired
    IMsgLogService iMsgLogService;

    @Autowired
    private RabbitTemplate rabbitTemplate;

    @Test
    void  send(Mail mail) {
        String msgId = UUID.randomUUID().toString();
        mail.setMsgId(msgId);

        MsgLog msgLog = new MsgLog();
        msgLog.setMsgId(msgId)
                .setMsg(new Gson().toJson(mail))
                .setExchange(RabbitConfig.MAIL_EXCHANGE_NAME)
                .setRoutingKey( RabbitConfig.MAIL_ROUTING_KEY_NAME);
        iMsgLogService.save(msgLog);// 消息入库

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

    }

6.MailConsumer消费消息, 发送邮件
其实就完成了3件事: 1.保证消费幂等性, 2.发送邮件, 3.更新消息状态, 手动ack

@Component
@Slf4j
public class MailConsumer {
    @Autowired
    private IMsgLogService msgLogService;

    @Autowired
    private MailUtil mailUtil;

    @RabbitListener(queues = RabbitMqConfig.MAIL_QUEUE_NAME)
    public void consume(String content, Message message, Channel channel) throws IOException {
        Mail mail = new Gson().fromJson(content,Mail.class);
        log.info("收到消息: {}", mail.toString());

        String msgId = mail.getMsgId();
        MsgLog msgLog = msgLogService.getById(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);
        }
    }
}

7.定时任务重新投递发送失败的消息

@Component
@Slf4j
public class ResendMsg {

    @Autowired
    private IMsgLogService 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)");
        System.out.println("开始执行定时任务(重新投递消息)");

        List msgLogs = 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(), 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)");
    }

8.其他相关代码
实体类

@Data
@EqualsAndHashCode(callSuper = false)
@Accessors(chain = true)
@TableName("msg_log")
public class MsgLog implements Serializable {

    private static final long serialVersionUID = 1L;

    /**
     * 消息唯一标识
     */
    private String msgId;

    /**
     * 消息体, json格式化
     */
    private String msg;

    /**
     * 交换机
     */
    private String exchange;

    /**
     * 路由键
     */
    private String routingKey;

    /**
     * 状态: 0投递中 1投递成功 2投递失败 3已消费
     */
    private Integer status;

    /**
     * 重试次数
     */
    private Integer tryCount;

    /**
     * 下一次重试时间
     */
    private LocalDateTime nextTryTime;

    /**
     * 创建时间
     */
    private LocalDateTime createTime;

    /**
     * 更新时间
     */
    private LocalDateTime updateTime;

发送邮件对象 Mail

@Getter
@Setter
@NoArgsConstructor
@AllArgsConstructor
public class Mail {
    private String to;

    private String title;

    private String content;

    private String msgId;// 消息id
}

常量类Constant

public class Constant {

    public interface LogType {
        Integer LOGIN = 1;// 登录
        Integer LOGOUT = 2;// 登出
    }

    public interface MsgLogStatus {
        Integer DELIVERING = 0;// 消息投递中
        Integer DELIVER_SUCCESS = 1;// 投递成功
        Integer DELIVER_FAIL = 2;// 投递失败
        Integer CONSUMED_SUCCESS = 3;// 已消费
    }
}

MsgLogMapper.java

public interface MsgLogMapper extends BaseMapper {

    List selectTimeoutMsg();

}

MsgLogMapper.xml

    
        select *
        from msg_log
        where status = 0
        and next_try_time <= now()
    

IMsgLogService.java

public interface IMsgLogService extends IService {

    void updateStatus(String msgId, Integer status);

    List selectTimeoutMsg();

    void updateTryCount(String msgId, LocalDateTime tryTime);

}

MsgLogServiceImpl.java

@Service
public class MsgLogServiceImpl extends ServiceImpl implements IMsgLogService {

    @Autowired
    private MsgLogMapper msgLogMapper;

    @Override
    public void updateStatus(String msgId, Integer status) {
        MsgLog msgLog = new MsgLog();
        msgLog.setMsgId(msgId);
        msgLog.setStatus(status);
        msgLog.setUpdateTime(LocalDateTime.now());
        msgLogMapper.updateById(msgLog);
    }



    @Override
    public List selectTimeoutMsg() {
        return msgLogMapper.selectTimeoutMsg();
    }

    @Override
    public void updateTryCount(String msgId, LocalDateTime tryTime) {
        LocalDateTime nextTryTime = tryTime.plusMinutes(1);
        MsgLog msgLog = new MsgLog();
        msgLog.setMsgId(msgId);
        msgLog.setNextTryTime(nextTryTime);
        msgLogMapper.updateById(msgLog);
    }
}