cpp/examples/old_api/fanout/listener.cpp

/*
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 *
 */


/**
 *  listener.cpp
 *
 *  This program is one of two programs designed to be used
 *  together.
 *
 *    fanout_producer.cpp
 *
 *      Publishes messages to the "amq.fanout" exchange.
 *
 *    listener.cpp  (this program)
 *
 *      Creates a private queue, binds it to the "amq.fanout"
 *      exchange, and reads messages from its queue as they
 *      arrive. Messages sent before the listener binds the queue are
 *      not received.
 *
 *      Multiple listeners can run at the same time.
 *
 */


#include <qpid/client/Connection.h>
#include <qpid/client/Session.h>
#include <qpid/client/Message.h>
#include <qpid/client/MessageListener.h>
#include <qpid/client/SubscriptionManager.h>

#include <cstdlib>
#include <iostream>

using namespace qpid::client;
using namespace qpid::framing;

      
class Listener : public MessageListener{
  private:
    SubscriptionManager& subscriptions;
  public:
    Listener(SubscriptionManager& subscriptions);
    virtual void received(Message& message);
};

Listener::Listener(SubscriptionManager& subs) : subscriptions(subs)
{}

void Listener::received(Message& message) {
    std::cout << "Message: " << message.getData() << std::endl;
    if (message.getData() == "That's all, folks!") {
        std::cout << "Shutting down listener for " << message.getDestination()
                  << std::endl;
        subscriptions.cancel(message.getDestination());
    }
}

int main(int argc, char** argv) {
    const char* host = argc>1 ? argv[1] : "127.0.0.1";
    int port = argc>2 ? atoi(argv[2]) : 5672;

    Connection connection;
    try {
        connection.open(host, port);
        Session session =  connection.newSession();

        //--------- Main body of program --------------------------------------------

        // Each client creates its own private queue, using the 
        // session id to guarantee a unique name. It then routes
        // all messages from the fanout exchange to its own queue
        // by binding to the queue.
        //
        // The binding specifies a binding key, but for a fanout
        // exchange, the binding key is optional and is not used
        // for routing decisions. It can be useful for tracking
        // messages and routing in logs.

        std::string myQueue=session.getId().getName();
        session.queueDeclare(arg::queue=myQueue, arg::exclusive=true,
                             arg::autoDelete=true);

        session.exchangeBind(arg::exchange="amq.fanout", arg::queue=myQueue, arg::bindingKey="my-key");

        // Create a listener and subscribe it to my queue.
        SubscriptionManager subscriptions(session);
        Listener listener(subscriptions);
        subscriptions.subscribe(listener, myQueue);

        // Receive messages until the subscription is cancelled
        // by Listener::received()
        std::cout << "Listening" << std::endl;
        subscriptions.run();

        //---------------------------------------------------------------------------

        connection.close();
        return 0;
    } catch(const std::exception& error) {
        std::cout << error.what() << std::endl;
    }
    return 1;   
}