无法使用 AMQP-CPP 在 RabbitMQ 服务器上成功发布消息

Question

I'm trying to make a simple console application on windows. I have installed AMQP-CPP and included the library on my Visual Studio project. My task is to create the simple communication with the rabbitmq server.

The main function is:

#include <amqpcpp.h>
#include "rabbitmqModels.h"

int main(){

    string msg = "hello world";
    string queueName = "message_queue";
    string exchangeName = "myexchange";
    string routingKey = "hello";

    Address address("amqp://guest:guest@localhost:15672");
    MyConnectionHandler myHandler;
    Connection connection(&myHandler, address);
    Channel channel(&connection);

    channel.declareQueue(queueName);
    channel.declareExchange(exchangeName, direct).onSuccess([]();
    channel.bindQueue(exchangeName, queueName, routingKey);
    channel.publish(exchangeName, routingKey, msg, msg.size());

    return 0;
}

where rabbitmqModels.h code is:

using namespace AMQP;
class MyConnectionHandler : public ConnectionHandler
{
private:
    /**
     *  Method that is called by the AMQP library every time it has data
     *  available that should be sent to RabbitMQ.
     *  @param  connection  pointer to the main connection object
     *  @param  data        memory buffer with the data that should be sent to RabbitMQ
     *  @param  size        size of the buffer
     */
    virtual void onData(Connection* connection, const char* data, size_t size)
    {
        // @todo
        //  Add your own implementation, for example by doing a call to the
        //  send() system call. But be aware that the send() call may not
        //  send all data at once, so you also need to take care of buffering
        //  the bytes that could not immediately be sent, and try to send
        //  them again when the socket becomes writable again
    }

    virtual void onReady(Connection* connection) override
    {
        // @todo
        //  add your own implementation, for example by creating a channel
        //  instance, and start publishing or consuming
        std::cout << "Connection is established...\n";

    }

    virtual void onError(Connection* connection, const char* message)
    {
        // report error
        std::cout << "Connection Error: " << message << std::endl;
    }

    virtual void onClosed(Connection* connection)
    {
        std::cout << "closed" << std::endl;

    }

    virtual void onConnected(Connection* connection)
    {
        std::cout << "connected" << std::endl;
    }
};

The code builds without errors. Note that my rabbitmq server runs on localhost:15672 and I have defined both the queue and the exchange/routing key.

The thing is that I cannot see any message coming to my defined queue on the server. Do I have to use only TCPHandler? I can't find any implementation of TCPHandler for windows. Can you please provide any help? Thanks in advance!

Answer 1

Port 15672 is the default HTTP port for the management web interface and REST API. You want to use the AMQP port which is 5672 .

Change your code to this:

Address address("amqp://guest:guest@localhost:5672");

Please note that the RabbitMQ documentation is very thorough. Please take the time to read it and complete one of the language-specific tutorials.

---

_{the RabbitMQ team monitors the rabbitmq-users mailing list and only sometimes answers questions on StackOverflow.}

Answer 2

It's possible that your application completes execution before the channel is even ready. Try waiting for channel.onReady() before performing any channel operations. To do this you will need an event loop library like libev, libevent or libuv.

main

#include <amqpcpp.h>
#include "rabbitmqModels.h"
#include <amqpcpp/libev.h>
#include <ev.h>

int main()
{

    string msg = "hello world";
    string queueName = "message_queue";
    string exchangeName = "myexchange";
    string routingKey = "hello";

    // Event loop
    auto *loop = EV_DEFAULT;

    Address address("amqp://guest:guest@localhost:5672");
    MyLibEvHandler myHandler(loop);
    Connection connection(&myHandler, address);
    Channel channel(&connection);

    channel.onReady([&channel]() {
        channel.declareQueue(queueName);
        channel.declareExchange(exchangeName, direct).onSuccess([]();
        channel.bindQueue(exchangeName, queueName, routingKey);
        channel.publish(exchangeName, routingKey, msg, msg.size());
    });

    // Run loop
    ev_run(loop, 0);

    return 0;
}

MyLibEvHandler must inherit LibEvHandler

There are good examples here (although they are using TCP): https://github.com/CopernicaMarketingSoftware/AMQP-CPP/tree/master/examples