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/*
* 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.
*/
using System;
using System.Configuration;
using System.IO;
using System.Text;
using System.Threading;
using org.apache.qpid.client;
using org.apache.qpid.transport;
namespace org.apache.qpid.example.pubsub
{
/// <summary>
/// This program is one of two programs designed to be used
/// together. These programs use the topic exchange.
///
/// Publisher:
///
/// Publishes to a broker, specifying a routing key.
///
/// Listener (this program):
///
/// Reads from a queue on the broker using a message listener.
///
/// </summary>
internal class Listener
{
public static int _count = 4;
private static void Main(string[] args)
{
string host = ConfigurationManager.AppSettings["Host"];
int port = int.Parse(ConfigurationManager.AppSettings["Port"]);
string virtualhost = ConfigurationManager.AppSettings["VirtualHost"];
string username = ConfigurationManager.AppSettings["Username"];
string password = ConfigurationManager.AppSettings["Password"];
Client connection = new Client();
try
{
connection.Connect(host, port, virtualhost, username, password);
IClientSession session = connection.CreateSession(50000);
//--------- Main body of program --------------------------------------------
lock (session)
{
Console.WriteLine("Listening for messages ...");
// Create a listener
prepareQueue("usa", "usa.#", session);
prepareQueue("europe", "europe.#", session);
prepareQueue("news", "#.news", session);
prepareQueue("weather", "#.weather", session);
while (_count > 0)
{
Monitor.Wait(session);
}
}
//---------------------------------------------------------------------------
connection.Close();
}
catch (Exception e)
{
Console.WriteLine("Error: \n" + e.StackTrace);
}
}
private static void prepareQueue(string queue, string routing_key, IClientSession session)
{
// Create a unique queue name for this consumer by concatenating
// the queue name parameter with the Session ID.
Console.WriteLine("Declaring queue: " + queue);
session.QueueDeclare(queue, Option.EXCLUSIVE, Option.AUTO_DELETE);
// Route messages to the new queue if they match the routing key.
// Also route any messages to with the "control" routing key to
// this queue so we know when it's time to stop. A publisher sends
// a message with the content "That's all, Folks!", using the
// "control" routing key, when it is finished.
session.ExchangeBind(queue, "amq.topic", routing_key);
session.ExchangeBind(queue, "amq.topic", "control");
// subscribe the listener to the queue
IMessageListener listener = new MessageListener(session);
session.AttachMessageListener(listener, queue);
session.MessageSubscribe(queue);
}
}
public class MessageListener : IMessageListener
{
private readonly IClientSession _session;
private readonly RangeSet _range = new RangeSet();
public MessageListener(IClientSession session)
{
_session = session;
}
public void MessageTransfer(IMessage m)
{
BinaryReader reader = new BinaryReader(m.Body, Encoding.UTF8);
byte[] body = new byte[m.Body.Length - m.Body.Position];
reader.Read(body, 0, body.Length);
ASCIIEncoding enc = new ASCIIEncoding();
string message = enc.GetString(body);
Console.WriteLine("Message: " + message + " from " + m.Destination);
// Add this message to the list of message to be acknowledged
_range.Add(m.Id);
if (message.Equals("That's all, folks!"))
{
Console.WriteLine("Shutting down listener for " + m.DeliveryProperties.GetRoutingKey());
Listener._count--;
// Acknowledge all the received messages
_session.MessageAccept(_range);
lock (_session)
{
Monitor.Pulse(_session);
}
}
}
}
}
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