Chapter 48. WCF QuickStart

48.1. Introduction

The WCF quickstart application shows how to configure your WCF services using dependency injection and how to to apply AOP advice to your services. It is based on the same interfaces used in the portable service abstractions quickstart example that demonstrates similar features for .NET Remoting, Enterprise Services, and ASMX web sevices. The quickstart example is only available as a VS.NET 2008 solution.

There are two server applications in the solution, one is a web application where the WCF service will be hosted, and the other is a self-hosting console application, Spring.WcfQuickStart.Server.2008. The client application is located in Sprng.WcfQuickStart.ClientApp.2008. To run the solution make sure that all three projects are set to startup.

[Note]Note

To follow this Quarts QuickStart load the solution file found in the directory <spring-install-dir>\examples\Spring\Spring.WcfQuickStart

48.2. The server side

The service contract is shown below

    [ServiceContract(Namespace = "http://Spring.WcfQuickStart")]
    public interface ICalculator
    {
        [OperationContract]
        double Add(double n1, double n2);
        [OperationContract]
        double Subtract(double n1, double n2);
        [OperationContract]
        double Multiply(double n1, double n2);
        [OperationContract]
        double Divide(double n1, double n2);
        [OperationContract]
        string GetName();
    }

and the implementation is straightforward, only adding a property that controls how long each method should sleep. An abbreviated listing of the implementation is shown below

    public class CalculatorService : ICalculator
    {
        private int sleepInSeconds;

        public int SleepInSeconds
        {
            get { return sleepInSeconds; }
            set { sleepInSeconds = value; }
        }

        public double Add(double n1, double n2)
        {
            Thread.Sleep(sleepInSeconds*1000);
            return n1 + n2;
        }


        // other methods omitted for brevity.

    }

48.2.1. WCF Dependency Injection and AOP in self-hosted application

The approach using dynamic proxies is used in the console application inside the Spring.WcfQuickStart.Server.2008 project. For more information on this approach refer to this section in the reference docs. The configuration of your service is done as you would typically do with Spring, including applying of any AOP advice. The class is hosted inside the console application through the use of Spring's ServiceHostFactoryObject exporter. The configuration for the server console application is shown below.

    <objects xmlns="http://www.springframework.net"
             xmlns:aop="http://www.springframework.net/aop">
     
      <!-- Service definition -->
      <object id="calculator" singleton="false"
              type="Spring.WcfQuickStart.CalculatorService, Spring.WcfQuickStart.ServerApp">
        <property name="SleepInSeconds" value="1"/>
      </object>

      <object id="serviceOperation" type="Spring.Aop.Support.SdkRegularExpressionMethodPointcut, Spring.Aop">
        <property name="pattern" value="Spring.WcfQuickStart.*"/>
      </object>
      
      <object id="perfAdvice" type="Spring.WcfQuickStart.SimplePerformanceInterceptor, Spring.WcfQuickStart.ServerApp">
        <property name="Prefix" value="Service Layer Performance"/>
      </object>
      
      <aop:config>
        <aop:advisor pointcut-ref="serviceOperation" advice-ref="perfAdvice"/>
      </aop:config>

      <!-- host the service object -->
      <object id="calculatorServiceHost" type="Spring.ServiceModel.Activation.ServiceHostFactoryObject, Spring.Services">
        <property name="TargetName" value="calculator" />
      </object>

    </objects>

Look at the standard WCF configuration section in App.config for additional configuration details. In that section you will see that the name of the WCF service corresponds to the name of the service object inside the spring container.

48.2.2. WCF Dependency Injection and AOP in IIS web application

Much of the configuration ob the objects is the same as before, the .svc file though refers to the name of the service inside the Spring container as well as using Spring's Spring.ServiceModel.Activation.ServiceHostFactory. The .svc file is shown below.

<%@ ServiceHost Language="C#" Debug="true" Service="calculator" 
                                           Factory="Spring.ServiceModel.Activation.ServiceHostFactory" %>

48.3. Client access

The project Spring.WcfQuickStart.ClientApp.2008 is a console application that calls the two WCF services. It creates a client side proxy based on using ChannelFactory<T>.CreateChannel. Running the client application produces the following output.

--- Press <return> to continue ---
Web Calculator
Add(1, 1) : 2
Divide(11, 2) : 5.5
Multiply(2, 5) : 10
Subtract(7, 4) : 3

ServerApp Calculator
Add(1, 1) : 2
Divide(11, 2) : 5.5
Multiply(2, 5) : 10
Subtract(7, 4) : 3

--- Press <return> to continue ---