[Java知识库]RabbitMQ整合SpringBoot

实现延迟队列功能

application.properties添加如下配置

spring.rabbitmq.host=IP
spring.rabbitmq.port=PORT
spring.rabbitmq.username=USERNAME
spring.rabbitmq.password=PASSWORD

实现延迟队列的功能

1. 首先添加TTL配置类

/**
 * ttl队列 配置文件类代码
 */
@Configuration
public class TtlQueueConfig {
    public static final String X_EXCHANGE = "X";
    public static final String QUEUE_A = "QA";
    public static final String QUEUE_B = "QB";
    public static final String Y_DEAD_LETTER_EXCHANGE = "Y";
    public static final String DEAD_LETTER_QUEUE = "QD";
    public static final String QUEUE_C = "QC";


    @Bean("queueC")
    public Queue queueC() {
        Map<String, Object> args = new HashMap<>(3);
        //设置死信交换机
        args.put("x-dead-letter-exchange",Y_DEAD_LETTER_EXCHANGE);
        args.put("x-dead-letter-routing-key","YD");

        //设置死信routingkey
        return QueueBuilder.durable(QUEUE_C).withArguments(args).build();
    }

    @Bean
    public Binding queuecBindingX(@Qualifier("queueC") Queue queueC,
                                  @Qualifier("xExchange") DirectExchange xExchange){
        return BindingBuilder.bind(queueC).to(xExchange).with("XC");
    }


    // 声明 xExchange
    @Bean("xExchange")
    public DirectExchange xExchange(){
        return new DirectExchange(X_EXCHANGE);
    }
    // 声明 xExchange
    @Bean("yExchange")
    public DirectExchange yExchange(){
        return new DirectExchange(Y_DEAD_LETTER_EXCHANGE);
    }
    //声明队列 A ttl 为 10s 并绑定到对应的死信交换机
    @Bean("queueA")
    public Queue queueA(){
    Map<String, Object> args = new HashMap<>(3);
    //声明当前队列绑定的死信交换机
    args.put("x-dead-letter-exchange", Y_DEAD_LETTER_EXCHANGE);
    //声明当前队列的死信路由 key
    args.put("x-dead-letter-routing-key", "YD");
    //声明队列的 TTL
    args.put("x-message-ttl", 10000);
    return QueueBuilder.durable(QUEUE_A).withArguments(args).build();
    }
    // 声明队列 A 绑定 X 交换机
    @Bean
    public Binding queueaBindingX(@Qualifier("queueA") Queue queueA,
                                  @Qualifier("xExchange") DirectExchange xExchange){
        return BindingBuilder.bind(queueA).to(xExchange).with("XA");
    }
    //声明队列 B ttl 为 40s 并绑定到对应的死信交换机
    @Bean("queueB")
    public Queue queueB(){
        Map<String, Object> args = new HashMap<>(3);
        //声明当前队列绑定的死信交换机
        args.put("x-dead-letter-exchange", Y_DEAD_LETTER_EXCHANGE);
        //声明当前队列的死信路由 key
        args.put("x-dead-letter-routing-key", "YD");
        //声明队列的 TTL
        args.put("x-message-ttl", 40000);
        return QueueBuilder.durable(QUEUE_B).withArguments(args).build();
    }
    //声明队列 B 绑定 X 交换机
    @Bean
    public Binding queuebBindingX(@Qualifier("queueB") Queue queue1B,
                                  @Qualifier("xExchange") DirectExchange xExchange){
        return BindingBuilder.bind(queue1B).to(xExchange).with("XB");
    }
    //声明死信队列 QD
    @Bean("queueD")
    public Queue queueD(){
        return new Queue(DEAD_LETTER_QUEUE);
    }
    //声明死信队列 QD 绑定关系
    @Bean
    public Binding deadLetterBindingQAD(@Qualifier("queueD") Queue queueD,
                                        @Qualifier("yExchange") DirectExchange yExchange){
        return BindingBuilder.bind(queueD).to(yExchange).with("YD");
    } }

2. 在控制层编写生产者代码

@Slf4j
@RequestMapping("ttl")
@RestController
public class SendMsgController {
    @Autowired
    private RabbitTemplate rabbitTemplate;
    @GetMapping("sendMsg/{message}")
    public void sendMsg(@PathVariable String message){
        log.info("当前时间：{},发送一条信息给两个 TTL 队列:{}", new Date(), message);
        rabbitTemplate.convertAndSend("X", "XA", "消息来自 ttl 为 10S 的队列: "+message);
        rabbitTemplate.convertAndSend("X", "XB", "消息来自 ttl 为 40S 的队列: "+message);
    }
//    开始发消息
    @GetMapping("sendExpirationMsg/{message}/{ttlTime}")
    public void sendMsg(@PathVariable String message,@PathVariable String ttlTime) {
        log.info("当前时间：{},发送一条时长{}毫秒 TTL 信息给队列 C:{}", new Date(),ttlTime, message);
        rabbitTemplate.convertAndSend("X","XC",message,(Message msg)->{
            //设置发送消息时候的延迟时长
            msg.getMessageProperties().setExpiration(ttlTime);
            return msg;
        });
    }

3. 配置消费者监听器

/**
 * 队列ttl消费者
 */
@Slf4j
@Component
public class DeadLetterQueueConsumer {
    @RabbitListener(queues = "QD")
    public void receiveD(Message message, Channel channel) throws IOException {
        String msg = new String(message.getBody());
        log.info("当前时间：{},收到死信队列信息{}", new Date().toString(), msg);
    }
}

以上代码存在一定的问题

如果使用在消息属性上设置 TTL 的方式，消
息可能并不会按时“死亡“，因为 RabbitMQ 只会检查第一个消息是否过期，如果过期则丢到死信队列，
如果第一个消息的延时时长很长，而第二个消息的延时时长很短，第二个消息并不会优先得到执行。

使用RabbitMQ插件实现延迟队列

在官网上下载 https://www.rabbitmq.com/community-plugins.html，下载
rabbitmq_delayed_message_exchange 插件，然后解压放置到 RabbitMQ 的插件目录。
进入 RabbitMQ 的安装目录下的 plgins 目录，执行下面命令让该插件生效，然后重启 RabbitMQ
/usr/lib/rabbitmq/lib/rabbitmq_server-3.8.8/plugins
rabbitmq-plugins enable rabbitmq_delayed_message_exchange
添加延时插件以后,新增交换机多了一个Type类型

接下来开始编写代码，步骤跟上面一样

/**
 * @ClassName DelayedQueueConfig
 * @Description
 * @Author tunan
 * @Date 2022/07/14/0:04
 */
@Configuration
public class DelayedQueueConfig {
//    交换机
    public static final String DELAYED_EXCHANGE_NAME = "delayed.exchange"
//    队列
    public static final String DELAYED_QUEUE_NAME = "delayed.queue";
//    routingkey
    public static final String DELAYED_ROUTING_KEY = "delayed.routingkey";
    @Bean
    public Queue delayedQueue() {
        return new Queue(DELAYED_QUEUE_NAME);
    }
    @Bean
    public Binding delayedQueueBinding(@Qualifier("delayedQueue") Queue delayedQueue,
                                       @Qualifier("delayedExchange") CustomExchange delayedExchange
    ) {
        return BindingBuilder.bind(delayedQueue).to(delayedExchange).with(DELAYED_ROUTING_KEY).noargs();
    }


    @Bean
    public CustomExchange delayedExchange() {
        Map<String, Object> args = new HashMap<>();
        args.put("x-delayed-type","direct");
        /**
         * (String name, String type, boolean durable, boolean autoDelete, Map<String, Object> arguments)
         *                            持久化                                其他参数
         */
        return new CustomExchange(DELAYED_EXCHANGE_NAME,"x-delayed-message",true,false,args);
    }
}

//    开始发消息，基于插件的消息，及延迟的时间
    public static final String DELAYED_EXCHANGE_NAME = "delayed.exchange";
    public static final String DELAYED_ROUTING_KEY = "delayed.routingkey";
    @GetMapping("sendDelayMsg/{message}/{delayTime}")
    public void sendMsg(@PathVariable String message,@PathVariable Integer delayTime) {
        log.info(" 当 前 时 间 ： {}, 发送一条延迟 {} 毫秒的信息给队列 delayed.queue:{}", new
                Date(),delayTime, message);
        rabbitTemplate.convertAndSend(DelayedQueueConfig.DELAYED_QUEUE_NAME,DelayedQueueConfig.DELAYED_ROUTING_KEY,message,(Message msg)->{
            //设置发送消息时候的延迟时长
            msg.getMessageProperties().setDelay(delayTime);
            return msg;
        });

    }

@Component
@Slf4j
public class DelayQueue {
    @RabbitListener(queues = DelayedQueueConfig.DELAYED_QUEUE_NAME)
    public void receive(Message message) {
        String msg = new String(message.getBody());
        log.info("当前时间：{},收到延时队列的消息：{}", new Date().toString(), msg);
    }
}

测试结果，第二个消息先被消费掉，符合预期