java - Rabbitmq java客户端消费者handleDelivery方法没有被调用

Question

这是一个非常人为的rabbitmq应用程序示例，它在一个主方法中既是消息的生产者又是消息的消费者。问题是重写的handleDelivery方法中的代码永远不会被执行。我使用 Rabbitmq 仪表板并看到队列已满并消耗。并且handleConsumeOk 中的行被打印。由于我是rabbitmq的新手，我想知道我是否做了一些根本性错误的事情，或者我只是得到了“当该消费者收到 basic.deliver 时调用”的想法错误。

public class RabbitMain {

    public static void main(String[] args) throws IOException, TimeoutException, InterruptedException {
        Connection connection = Utils.getConnection("test");
        String payload = "hello world!";
        try (Channel channel = connection.createChannel()){
            channel.exchangeDeclare("sampleExchange", BuiltinExchangeType.TOPIC, true);
            channel.basicPublish("sampleExchange", "testKey", null, payload.getBytes());
        }

        System.out.println("Consume...");

        try (Channel channel = connection.createChannel()){
            channel.exchangeDeclare("sampleExchange", BuiltinExchangeType.TOPIC, true);
            channel.queueDeclare("testQueue", true, false, false, null);
            channel.queueBind("testQueue", "sampleExchange", "testKey");

            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);
                    System.out.println("Received: " + message);
                }

                @Override
                public void handleConsumeOk(String consumerTag) {
                    System.out.println("handled consume ok");
                }
            };

            Thread.sleep(2000);

            channel.basicConsume("testQueue", true, consumer);
        }
    }
}

Answer 1

在任何队列绑定(bind)到消息之前，您将消息发布到exhnage。 RabbitMQ 将丢弃任何无法路由到队列的消息。

做

channel.queueDeclare("testQueue", true, false, false, null);
channel.queueBind("testQueue", "sampleExchange", "testKey");

在调用channel.basicPublish之前。