實現思路：利用mq的ttl設定訊息失效時間 當達到設定時間後通過交換機到達死信佇列中，消費者端繫結讀取死信佇列中資訊來達到延時傳送訊息的功能。

demo 如下：

（1）在pom.xml 中引入rabbitMq相關包

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-amqp</artifactId>
        </dependency>

（2）建立rabbitMq連線的工具類

public class MqConnectionUtil {

    public static Connection getConnection() throws Exception {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        factory.setPort(5672);
        factory.setVirtualHost("virtualHost_wl");
        factory.setUsername("admin");
        factory.setPassword("admin");
        Connection connection = factory.newConnection();
        return connection;
    }
}

（3）建立生產者傳送訊息

public class Send {

    private final static String QUEUE_NAME = "msg_ttl_queue";

    public static void main(String[] argv) throws Exception {
        //獲取連線
        Connection connection = MqConnectionUtil.getConnection();
        //建立通道
        Channel channel = connection.createChannel();
        //設定延時佇列
        HashMap<String, Object> args = new HashMap<>();
        args.put("x-dead-letter-exchange", "delay-exchange");
        args.put("x-dead-letter-routing-key", "msg_ttl_routingKey");
        channel.queueDeclare("delay_queue", true, false, false, args);
        //宣告佇列
        channel.queueDeclare(QUEUE_NAME, true, false, false, null);
        //繫結路由(delay-queue佇列訊息失效之後轉發到msg_ttl_queue中)
        channel.queueBind(QUEUE_NAME, "delay-exchange", "msg_ttl_routingKey");
        //設定延時屬性
        AMQP.BasicProperties.Builder builder = new AMQP.BasicProperties.Builder();
        //設定延時時間 1分鐘
        AMQP.BasicProperties properties = builder.expiration("60000").deliveryMode(2).build();
        //訊息內容
        SimpleDateFormat sft = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String message = "生產者建立時間： " + sft.format(new Date());
        channel.basicPublish("", "delay_queue", properties, message.getBytes());
        System.out.println("Sent： '" + message + "'");
        //關閉通道和連線
        channel.close();
        connection.close();
    }
}

（4）建立對應的消費者接受訊息

public class Receive {

    private final static String QUEUE_NAME = "msg_ttl_queue";

    public static void main(String[] argv) throws Exception {
        //獲取連線
        Connection connection = MqConnectionUtil.getConnection();
        //建立通道
        Channel channel = connection.createChannel();
        // 宣告佇列
        channel.queueDeclare(QUEUE_NAME, true, false, false, null);
        // 定義佇列的消費者
        MyConsumer myConsumer = new MyConsumer(channel);
        // 監聽佇列
        channel.basicConsume(QUEUE_NAME, true, myConsumer);
    }
}

自定義消費者類為：

public class MyConsumer extends DefaultConsumer {
    public MyConsumer(Channel channel) {
        super(channel);
    }

    @Override
    public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body) throws IOException {
        SimpleDateFormat sft = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        System.out.println("消費者接受時間：" + sft.format(new Date()));
        System.out.println("consumerTag: " + consumerTag);
        System.out.println("envelope: " + envelope);
        System.out.println("properties: " + properties);
        System.out.println("body: " + new String(body));
    }
}

生產者傳送訊息到延時佇列：

 到達設定的失效時間1分鐘後到達指定的佇列中：

 設定的延時交換機為：

控制檯列印資訊為：

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