rabbitmq(9)延时消息

快来打我* 2022-05-29 14:09 152阅读 0赞

### 1、概述 ###

rabbitmq没有直接支持延时消息的功能，但可以通过死信队列实现延时消息的功能。

### 2、代码 ###

#### 2.1、生产者 ####

private final static String QUEUE_NAME = "MAIN_QUEUE";
    private final static String _DIRECT_NAME = "_delay_delay";
    
    public static void main(String[] args) throws Exception {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("192.168.1.7");
        factory.setUsername("root");
        factory.setPassword("123456");
    
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();
    
        channel.queueDeclare(QUEUE_NAME, true, false, false, null);
        channel.queueBind(QUEUE_NAME, "amq.direct", QUEUE_NAME);
    
        Map<String, Object> arguments = new HashMap<>();
        arguments.put("x-dead-letter-exchange", "amq.direct");
        arguments.put("x-dead-letter-routing-key", QUEUE_NAME);
        channel.queueDeclare(_DIRECT_NAME, true, false, false, arguments);
    
        // 延迟5秒
        long delay = 5*1000;
    
        String message = "Hello World!";
        AMQP.BasicProperties.Builder builder = new AMQP.BasicProperties.Builder();
        AMQP.BasicProperties properties = builder.expiration(delay+"").build();
        channel.basicPublish("", _DIRECT_NAME, properties, message.getBytes());
        System.out.println(" [x] Sent '" + message + "'");
    
        channel.close();
        connection.close();
    }

#### 2.2、消费者 ####

private final static String QUEUE_NAME = "MAIN_QUEUE";
    
    public static void main(String[] args) throws Exception {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("192.168.1.7");
        factory.setUsername("root");
        factory.setPassword("123456");
    
        Connection connection = factory.newConnection();
        Channel channel = connection.createChannel();
    
        channel.queueDeclare(QUEUE_NAME, true, false, false, null);
        System.out.println(" [*] Waiting for messages.");
        Consumer consumer = new DefaultConsumer(channel) {
            @Override
            public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties,
                    byte[] body) throws IOException {
                String message = new String(body, "UTF-8");
                System.out.println(" [x] Received '" + message + "'");
            }
        };
        channel.basicConsume(QUEUE_NAME, true, consumer);
    }