public static IFailedMessageHandler CreateFailureHandler(FailureHandlerType type, string queueName, string deadQueueName, string retryQueueName)
{
IFailedMessageHandler failureHandler = null;
if (type == FailureHandlerType.Discard)
{
failureHandler = new DiscardMessageHandler();
}
if (type == FailureHandlerType.AlwaysRollback)
{
failureHandler = new AlwaysRollBackHandler();
}
else if (type == FailureHandlerType.SendToBack)
{
failureHandler = new SendToBackHandler(
CreateAndGetQueue(deadQueueName));
}
else if (type == FailureHandlerType.RetrySendToDead)
{
failureHandler = new RetrySendToDeadLetterQueueHandler(
CreateAndGetQueue(deadQueueName));
}
else if (type == FailureHandlerType.SeparateRetry)
{
failureHandler = new SeparateRetryQueueHandler(
CreateAndGetQueue(retryQueueName));
}
return(failureHandler);
}
public void receiveMessage(IFailedMessageHandler failedMessageHandler)
{
if (incomingQueue == null)
{
throw new NullReferenceException("La coda di ricezione non è stata specificata");
}
gotMessage = null;
SetFormatter();
MessageQueueTransaction transaction = new MessageQueueTransaction();
transaction.Begin();
// Message message = null;
try
{
gotMessage = incomingQueue.Receive(TimeSpan.Zero, transaction);
Log("Received message ID: " + gotMessage.Id);
ProcessMessage();
transaction.Commit();
Log("Message processed OK");
}
catch (Exception e)
{
Log("Message failed");
TransactionAction transactionAction = TransactionAction.ROLLBACK;
if (gotMessage == null)
{
Log("Message couldn't be received: " + e.Message);
Log("Message couldn't be received (stak: " + e.StackTrace);
}
else
{
try
{
transactionAction = failedMessageHandler.HandleFailedMessage(gotMessage, transaction);
}
catch (Exception failureHandlerException)
{
Log("Error during failure handling: " + failureHandlerException.Message);
}
}
if (transactionAction == TransactionAction.ROLLBACK)
{
transaction.Abort();
Log("Transaction rolled back");
}
else
{
transaction.Commit();
Log("Transaction commited - message removed from queue");
}
}
}
/// <summary>
/// Receive message wrapped with a transaction to handle failures based on handler passed into ctor
/// </summary>
/// <param name="failedMessageHandler">Determines what implementation should be taken in the event of poisoned messages.</param>
private bool ReceiveMessage(msmq.MessageQueue incomingQueue, IFailedMessageHandler failedMessageHandler)
{
incomingQueue.MessageReadPropertyFilter.SetAll();
using (var transaction = new MessageQueueTransaction())
{
transaction.Begin();
Message message = null;
try
{
message = incomingQueue.Receive(TimeSpan.Zero, transaction);
Logger.LogDebug("Received message ID: " + message.Id);
ProcessMessage(message);
transaction.Commit();
Logger.LogDebug("Message processed OK");
return true;
}
catch (MessageQueueException msgQueueError)
{
if (msgQueueError.Message == "Time out for the requested operation has expired.")
{
// No message found to process before TimeSpan expired
// {gulp} Swallow exception
return false;
}
}
catch (Exception e)
{
Logger.LogDebug("Message failed");
TransactionAction transactionAction = TransactionAction.ROLLBACK;
if (message == null)
{
Logger.LogDebug("Message couldn't be received: " + e.Message);
}
else
{
try
{
transactionAction = failedMessageHandler.HandleFailedMessage(message, transaction);
}
catch (Exception failureHandlerException)
{
Logger.LogDebug("Error during failure handling: " + failureHandlerException.Message);
}
}
if (transactionAction == TransactionAction.ROLLBACK)
{
transaction.Abort();
Logger.LogDebug("Transaction rolled back");
}
else
{
transaction.Commit();
Logger.LogDebug("Transaction committed - message removed from queue");
}
}
return false;
}
}
private int ProcessMessages(msmq.MessageQueue queue, string retryQueueAddress, int messageMaxToProcessAtOneTime, IFailedMessageHandler failedMsgHandler)
{
int messageCount = 0;
while (queue.CanRead && messageCount < messageMaxToProcessAtOneTime)
{
bool msgReceivedSuccess = ReceiveMessage(queue, failedMsgHandler);
if (msgReceivedSuccess)
{
messageCount++;
}
else
{
return messageCount;
}
}
return messageCount;
}
