NServiceBus - Part 2

Continuing writing down my findings getting NServiceBus up and running.

Overal structure, simple:

There are two config sections that are important regarding NServiceBus

* MsmqTransportConfig
* UnicastBusConfig

MsmqTransportConfig

This section have information about the messages going in to the current process.

UnicastBusConfig

This section is used to say where a message should be sent.

Example:

The following section says that a specific message should be sent to a queue named testqueue on the 10.21.50.11 machine.

  <UnicastBusConfig>
    <MessageEndpointMappings>
      <add Messages="NServiceBusDemo.SomeMessage, NServiceBusDemo"
           Endpoint="testqueue@10.21.50.11"/>
    </MessageEndpointMappings>
  </UnicastBusConfig>

The following section says that all messages in the NServiceBusDemo assembly should be sent to the queue name testqueue on the local machine.

  <UnicastBusConfig>
    <MessageEndpointMappings>
      <add Messages="NServiceBusDemo" Endpoint="testqueue"/>
    </MessageEndpointMappings>
  </UnicastBusConfig>

Message Format

This class is used as the message for this example

    [Serializable]
    public class SomeMessage : IMessage
    {
        public string Text;
    }

By default there are two formatters available for serializing the messages to MSMQ. Binary and Xml. For both serializers a Label is set on the Message (MSMQ) with the following data:

<CorrId></CorrId><WinIdName>NO\mteinum</WinIdName>

The ResponseQueue on the Message is set to the inputqueue defined in MsmqTransportConfig

For my example:

DIRECT=OS:MORTEN\private$\NServiceBusDemoInputQueue

The body is the output from the XML.MessageSerializer:

<?xml version="1.0"?>
<Messages xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xmlns:xsd="http://www.w3.org/2001/XMLSchema"
    xmlns="http://tempuri.net/NServiceBusDemo">
 <SomeMessage>
  <Text>FooBar</Text>
 </SomeMessage>
</Messages>

If we are sending two messages, one of SomeMessage and another of type AnotherMessage, the serialized stream will look like:

<?xml version="1.0"?>
<Messages xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xmlns:xsd="http://www.w3.org/2001/XMLSchema"
          xmlns="http://tempuri.net/NServiceBusDemo">
 <SomeMessage>
  <Text>Hello World!</Text>
 </SomeMessage>
 <AnotherMessage>
  <Text>Hello World!</Text>
 </AnotherMessage>
</Messages>

Custom formatter

SOAP ...? :) Is it possible? sure :)

First we need to create a serializer class implementing the NServiceBus.Serialization.IMessageSerializer interface.

And since we want a SOAP formatted message we will use the formatter from the System.Runtime.Serialization.Formatters.Soap namespace.

And the implementation:

    public class SoapMessageSerializer : IMessageSerializer
    {
        private readonly SoapFormatter _formatter;

        public SoapMessageSerializer()
        {
            _formatter = new SoapFormatter
            {
                AssemblyFormat = FormatterAssemblyStyle.Simple,
                TypeFormat = FormatterTypeStyle.TypesWhenNeeded
            };
        }

        public void Serialize(IMessage[] messages, Stream stream)
        {
            _formatter.Serialize(stream, messages);
        }

        public IMessage[] Deserialize(Stream stream)
        {
            return (IMessage[])_formatter.Deserialize(stream);
        }
    }

We then need to configure the bus to use this, and we then need an extension class:

    public static class ConfigureSoapSerializer
    {
        public static Configure SoapSerializer(this Configure config)
        {
            config.Configurer.ConfigureComponent(
                typeof(SoapMessageSerializer),
                ComponentCallModelEnum.Singleton);

            return config;
        }
    }

We can then start the bus using this extension method

            var bus = Configure.With()
                .Log4Net()
                .StructureMapBuilder()
                .SoapSerializer()
                .MsmqTransport()
                .UnicastBus()
                    .ImpersonateSender(false)
                .CreateBus()
                .Start();

                bus.Send(new SomeMessage { Text = "Hello World!" });

And the message on the queue:

<SOAP-ENV:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                   xmlns:xsd="http://www.w3.org/2001/XMLSchema"
       xmlns:SOAP-ENC="http://schemas.xmlsoap.org/soap/encoding/"
       xmlns:SOAP-ENV="http://schemas.xmlsoap.org/soap/envelope/"
       xmlns:clr="http://schemas.microsoft.com/soap/encoding/clr/1.0"
       SOAP-ENV:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
 <SOAP-ENV:Body>
  <SOAP-ENC:Array SOAP-ENC:arrayType="a1:IMessage[1]"
     xmlns:a1="http://schemas.microsoft.com/clr/nsassem/NServiceBus/NServiceBus">
   <item href="#ref-3" />
  </SOAP-ENC:Array>
  <a2:SomeMessage id="ref-3"
     xmlns:a2="http://schemas.microsoft.com/clr/nsassem/NServiceBusDemo/NServiceBusDemo">
   <Text id="ref-5">Hello World!
  </a2:SomeMessage>
 </SOAP-ENV:Body>
</SOAP-ENV:Envelope>

Happy coding!