rabbitmq(9)延时消息

rabbitmq

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

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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

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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);
}
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