首页 > 解决方案 > 指定主题时使用直接交换的 RabbitMQ

问题描述

在我的应用程序中,我有 3 个类:
- 公司,它雇用工人来从事 3 种工作中的任何一种
- 工人,每个人可以做 2 份工作
- 管理员,它接收程序中所有消息的副本,并且可以向所有公司、所有工人或只是每个人

work.companies.companyName用于公司密钥和work.workers.workerName工作人员密钥,它们都使用默认交换和队列进行通信。管理员通过admin主题交换接收消息。

问题在于管理员 -> 其他所有人的沟通。它的工作原理与直接交换完全一样 - 我可以让公司和工人获得任何名称,甚至像“#”、“company1.#”等,他们不会收到任何东西,除非在管理员中我明确地使用“ work.companies.company1”。
我希望能够使用例如“work.companies.#”向所有公司发送消息。我究竟做错了什么?

管理员.java:

public class Administrator
{
    public static void main(String[] args) throws IOException, TimeoutException
    {
        new Thread(new TopicListener("admin", ign -> {})).start();
        TopicWriter writer = new TopicWriter();
    // lots of code

主题监听器.java:

public class TopicListener implements Runnable
{
    private final String EXCHANGE_NAME = "space";
    private String key;
    private Consumer<String> msgHandler;

    public TopicListener(String key, Consumer<String> msgHandler)
    {
        this.key = key;
        this.msgHandler = msgHandler;
    }

    @Override
    public void run()
    {
        try
        {
            ConnectionFactory factory = new ConnectionFactory();
            factory.setHost("localhost");
            Connection connection = factory.newConnection();
            Channel channel = connection.createChannel();

            channel.exchangeDeclare(EXCHANGE_NAME, "topic");

            String queueName = channel.queueDeclare().getQueue();
            channel.queueBind(queueName, EXCHANGE_NAME, key);

            com.rabbitmq.client.Consumer consumer = new DefaultConsumer(channel)
            {
                @Override
                public void handleDelivery(String consumerTag, Envelope envelope, AMQP.BasicProperties properties, byte[] body)
                {
                    String msg = new String(body, StandardCharsets.UTF_8);
                    System.out.println("Received: \"" + msg + "\"");
                    msgHandler.accept(msg);
                }
            };

            channel.basicConsume(queueName, true, consumer);
        }
        catch (IOException | TimeoutException e)
        { e.printStackTrace(); }
    }
}

TopicWriter.java:

public class TopicWriter
{
    private final String EXCHANGE_NAME = "space";
    private final Channel channel;

    public TopicWriter() throws IOException, TimeoutException
    {
        ConnectionFactory factory = new ConnectionFactory();
        factory.setHost("localhost");
        Connection connection = factory.newConnection();
        this.channel = connection.createChannel();

        channel.exchangeDeclare(EXCHANGE_NAME, "topic");
    }

    public void send(String msg, String key) throws IOException
    {
        channel.basicPublish(
                EXCHANGE_NAME,
                key,
                null,
                msg.getBytes(StandardCharsets.UTF_8));
    }
}

Company.java 包含:

new Thread(new TopicListener("space.agencies." + agencyID, ign -> {})).start();

Worker.java 包含:

new Thread(new TopicListener("space.carriers." + carrierID, consumer)).start();

标签: javarabbitmqrabbitmq-exchange

解决方案


我发现问题出在哪里:我试图使用 Topic 向每个人发送消息,在 RabbitMQ 中,Topic 用于指定谁应该接收消息。“#”或“*”应该在队列键声明中使用,而不是在使用给定键发送消息时使用。


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