ServiceStack，业务逻辑放在哪里？

Question

我对派生自 Service 的类有疑问，它是 ServiceStack 库的一部分。如果我设置一个派生自Service 的单独类并将Get 或Any 方法放在其中，那么一切运行正常，但是，问题是该类本身没有引用任何业务逻辑。只要我返回静态数据就可以了，但是如果我想将它集成到业务逻辑中，那就行不通了。我希望 Get 方法成为我的业务逻辑所在的同一类的一部分。那是糟糕的设计吗？如果我能做些什么来解决它？我得到的错误是派生自Service 的类无论出于何种原因都会被实例化（根据我目前的理解，这对我来说意义不大）。派生自Service 的类是否应该不只是整理路由逻辑？

这里有一些代码来说明我的问题：

这段代码运行良好，但问题是 DTO 类对 ClassWithBusinessLogic 类的内容一无所知：

public class ClassWithBusinessLogic
{
    public ClassWithBusinessLogic()
    {
        string hostAddress = "http://localhost:1337/";

        WebServiceHost host = new WebServiceHost("MattHost", new List<Assembly>() { typeof(DTOs).Assembly });
        host.StartWebService(hostAddress);
        Console.WriteLine("Host started listening....");

        Console.ReadKey();
    }
}

public class HelloWorldRequest : IReturn<string>
{
    public string FirstWord { get; set; }

    public HelloWorldRequest(string firstWord)
    {
        FirstWord = firstWord;
    }
}

public class DTO : Service
{
    public string Get(HelloWorldRequest request)
    {
        return request.FirstWord + " World!!!";
    }
}

现在，以下实际上是我想要的，但代码的行为出乎意料，基本上它不起作用：

public class ClassWithBusinessLogic : Service
{
    private string SomeBusinessLogic { get; set; }

    public ClassWithBusinessLogic()
    {
        string hostAddress = "http://localhost:1337/";

        //Simplistic business logic
        SomeBusinessLogic = "Hello";

        WebServiceHost host = new WebServiceHost("MyHost", new List<Assembly>() { typeof(DTO).Assembly });
        host.StartWebService(hostAddress);
        Console.WriteLine("Host started listening....");

        Console.ReadKey();
    }

    public string Get(HelloWorldRequest request)
    {
        return SomeBusinessLogic;
    }
}

public class HelloWorldRequest : IReturn<string>
{
    public string FirstWord { get; set; }

    public HelloWorldRequest(string firstWord)
    {
        FirstWord = firstWord;
    }
}

为了运行，还需要以下类：

public class WebServiceHost : AppHostHttpListenerBase
{
    public WebServiceHost(string hostName, List<Assembly> assembliesWithServices) : base(hostName, assembliesWithServices.ToArray())
    {
        base.Init();
    }

    public override void Configure(Funq.Container container)
    { }

    public void StartWebService(string hostAddress)
    {
        base.Start(hostAddress);
    }

    public void StopWebService()
    {
        base.Stop();
    }
}

public class WebServiceClient
{
    private JsonServiceClient Client { get; set; }

    public WebServiceClient(string hostAddress)
    {
        Client = new JsonServiceClient(hostAddress);
    }

    public ResponseType Get<ResponseType>(dynamic request)
    {
        return Client.Get<ResponseType>(request);
    }

    public void GetAsync<ResponseType>(dynamic request, Action<ResponseType> callback, Action<ResponseType, Exception> onError)
    {
        Client.GetAsync<ResponseType>(request, callback, onError);
    }
}

class Client_Entry
{
    static void Main(string[] args)
    {
        Client client = new Client();
    }
}

public class Client
{

    public Client()
    {
        Console.WriteLine("This is the web client. Press key to start requests");
        Console.ReadKey();

        string hostAddress = "http://localhost:1337/";
        WebServiceClient client = new WebServiceClient(hostAddress);

        var result = client.Get<string>(new HelloWorldRequest("Hello"));
        Console.WriteLine("Result: " + result);

        Console.WriteLine("Finished all requests. Press key to quit");
        Console.ReadKey();
    }

    private void OnResponse(HelloWorldRequest response)
    {
        Console.WriteLine(response.FirstWord);
    }

    private void OnError(HelloWorldRequest response, Exception exception)
    {
        Console.WriteLine("Error. Exception Message : " + exception.Message);
    }

}

Answer 1

第二个代码块的读取方式表明您的服务主机和服务是同一个对象。我看到的地方

public ClassWithBusinessLogic()
{
    string hostAddress = "http://localhost:1337/";

    //Simplistic business logic
    SomeBusinessLogic = "Hello";

    WebServiceHost host = new WebServiceHost("MyHost", new List<Assembly>() { typeof(DTO).Assembly });
    host.StartWebService(hostAddress);
    Console.WriteLine("Host started listening....");

    Console.ReadKey();
}

然后，该构造函数实例化 ServiceStack WebServiceHost，传入它自己的程序集 - 这让我相信 ServiceStack 将重新初始化 ClassWithBusinessLogic()，因为它继承自 Service，可能会陷入无限循环。

您需要将您的关注点分开 - 您的 Web 服务主机、您的 Web 服务和您的业务逻辑类都是分开的。以你正在做的方式混合它们只会让你感到沮丧。将它们分成各自的类。您的业​​务逻辑可以通过 IoC 容器传递到您的 Web 服务中。

所以你最终会得到类似的东西：

class BusinessLogicEngine : IBusinessLogic
---> Define your business logic interface and implementation, and all required business object entities

class WebService : Service
   constructor(IBusinessLogic)
---> Purely handles mapping incoming requests and outgoing responses to/from your business object entities. Recommend using AutoMapper (http://automapper.org/) 
---> Should also handle returning error codes to the client so as not to expose sensitive info (strack traces, IPs, etc)


class WebServiceHost
---> Constructor initializes the WebServiceHost with the typeof(WebService) from above.