HowTo: Receive messages from a session-enabled Message Broker

With the Message Broker API, you can send and receive messages from a Message Broker, in particular, session-enabled.

This article contains an example that shows how to receive messages from a session-enabled Azure Service Bus.

The Session ID has to be set for the Receive operation, as a session receiver is defined to be used until the session lock expires.

Consider that it is mandatory for session-enabled queues or topics to set the Session ID for each message you send. Otherwise, you get an exception from Azure Service Bus. The Session ID for each message is set as a MessageProperty.     

Receiving a message

The following code is the one used to receive a message:

&BrokerReceiverOptions = new()
&BrokerReceiverOptions.ReceiveMode = ReceiveModeOptions.ReceiveAndDelete
&BrokerReceiverOptions.SessionId = &SessionId

&receiveMessageOptions = new()
&receiveMessageOptions.MaxMessages = 3
&receiveMessageOptions.MaxWaitTime = 3
&receiveMessageOptions.BrokerReceiverOptions = &BrokerReceiverOptions

&MessageCollection = &MessageBroker.ReceiveMessages(&BrokerReceiverOptions.ToJson(), &errorMessages,&success)

Sending a message with a Session ID

The following code is the one used for sending a message with a Session ID:

&Message = new()
&Message.MessageId = GUID.NewGuid().ToString()
&Message.MessageBody = !"message body"

//Broker Properties 

&MessageProperty = new()
&MessageProperty.PropertyKey = !"SessionId"
&MessageProperty.PropertyValue = &SessionId.Trim()
&Message.MessageAttributes.Add(&MessageProperty)

//SEND

&success = &MessageBroker.SendMessage(&Message,"",&errorMessages)

if not &success
    for &errorMessage in &errorMessages
        msg(format(!"%1 (%2)",&errorMessage.Description, &errorMessage.Id), status)
    endfor
endif

&MessageBroker.Dispose()

Variables defined in the example

 

For the generated code, for Peek Lock operations, the lock is released when the lock expires (Message Lock duration defined for the queue or topic).
For Receive and Delete operations, the lock is released when the operation finishes.

See Also

Session-features