SpringBoot整合rabbitMq实现消息延时发送

2020 年 11 月 15 日
笔记

实现思路：利用mq的ttl设置消息失效时间当达到设置时间后通过交换机到达死信队列中，消费者端绑定读取死信队列中信息来达到延时发送消息的功能。

demo 如下：

（1）在pom.xml 中引入rabbitMq相关包

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

（2）创建rabbitMq连接的工具类

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）创建生产者发送消息

public class Send {

    private final static String QUEUE_NAME = "msg_ttl_queue";

    public static void main(String[] argv) throws Exception {
        //获取连接
        Connection connection = MqConnectionUtil.getConnection();
        //创建通道
        Channel channel = connection.createChannel();
        //设置延时队列
        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);
        //声明队列
        channel.queueDeclare(QUEUE_NAME, true, false, false, null);
        //绑定路由(delay-queue队列消息失效之后转发到msg_ttl_queue中)
        channel.queueBind(QUEUE_NAME, "delay-exchange", "msg_ttl_routingKey");
        //设置延时属性
        AMQP.BasicProperties.Builder builder = new AMQP.BasicProperties.Builder();
        //设置延时时间 1分钟
        AMQP.BasicProperties properties = builder.expiration("60000").deliveryMode(2).build();
        //消息内容
        SimpleDateFormat sft = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String message = "生产者创建时间： " + sft.format(new Date());
        channel.basicPublish("", "delay_queue", properties, message.getBytes());
        System.out.println("Sent： '" + message + "'");
        //关闭通道和连接
        channel.close();
        connection.close();
    }
}

（4）创建对应的消费者接受消息

public class Receive {

    private final static String QUEUE_NAME = "msg_ttl_queue";

    public static void main(String[] argv) throws Exception {
        //获取连接
        Connection connection = MqConnectionUtil.getConnection();
        //创建通道
        Channel channel = connection.createChannel();
        // 声明队列
        channel.queueDeclare(QUEUE_NAME, true, false, false, null);
        // 定义队列的消费者
        MyConsumer myConsumer = new MyConsumer(channel);
        // 监听队列
        channel.basicConsume(QUEUE_NAME, true, myConsumer);
    }
}

自定义消费者类为：

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("消费者接受时间：" + 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));
    }
}