ASP.NET Web API中實現版本的幾種方式

 

在ASP.NET Web API中，當我們的API發生改變，就涉及到版本問題了。如何實現API的版本呢？

 

1、通過路由設置版本

 

最簡單的一種方式是通過路由設置，不同的路由，不同的版本，不同的controller。

 

config.Routes.MapHttpRoute(
    name: "Food",
    routeTemplate: "api/v1/nutrition/foods/{foodid}",
    defaults:...
)

config.Routes.MapHttpRoute(
    name: "Foodv2",
    routeTemplate: "api/v2/nutrition/foods/{foodid}",
    defaults:...
)

 

2、通過HttpControllerSelector

 

通過更改HttpControllerSelector也可以實現。

 

首先寫一個繼承 DefaultHttpControllerSelector的類。

 

using System.Web.http.Dispatcher

public class CountingKsControllerSelector : DefaultHttpControllerSelector
{
    private HttpConfiguraion _config;
    
    public CountgKsControllerSelector(HttpConfiguraiton cofig) : base(config)
    {
        _config = config;
    }
    
    //設計就是返回HttpControllerDesriptor的過程
    public override System.Web.Http.Controllers.HttpControllerDescriptor SelectController(HttpRequestMessage request)
    {
        //獲取所有的controller鍵值集合
        var controllers = GetControllerMapping();
        
        //獲取路由數據
        var routeData = request.GetRouteData();
        
        //從路由中獲取當前controller的名稱
        var controllerName = (string)routeData.Values["controller"];
        
        HttpControllerDescriptor descriptor;
        
        if(controllers.TryGetValue(controllerName, out descriptor))
        {
            var version = "2";
            
            //從QueryString中獲取版本 
            var newName = string.Concat(controllerName, "V", version);
            
            HttpControllerDescriptor versionedDescriptor;
            
            if(controllers.TryGetValue(newName, out versionedDescriptor))
            {
                return versionedDescriptor;
            }
            
            return descriptor;
        }
        
        return null;
        
    }
}

 

在WebApiConfig.cs注冊自定義的ControllerSelector

 

config.Services.Replace(typeof(IHttpControllerSelector), new CountingKsControllerSelector(config) );

 

以上是大致的實現思路。具體來說可以通過如下幾種方式實現。

 

■ 通過Query String實現版本

客戶端大致這樣請求：

http://localhost:8901/api/nutrition/foods/4492/measures/7269?v=2

 

using System.Web.http.Dispatcher

public class CountingKsControllerSelector : DefaultHttpControllerSelector
{
    private HttpConfiguraion _config;
    
    public CountgKsControllerSelector(HttpConfiguraiton cofig) : base(config)
    {
        _config = config;
    }
    
    //設計就是返回HttpControllerDesriptor的過程
    public override System.Web.Http.Controllers.HttpControllerDescriptor SelectController(HttpRequestMessage request)
    {
        //獲取所有的controller鍵值集合
        var controllers = GetControllerMapping();
        
        //獲取路由數據
        var routeData = request.GetRouteData();
        
        //從路由中獲取當前controller的名稱
        var controllerName = (string)routeData.Values["controller"];
        
        HttpControllerDescriptor descriptor;
        
        if(controllers.TryGetValue(controllerName, out descriptor))
        {
            //var version = "2";
            
            //從QueryString中獲取版本 
            var version = GetVersionFromQueryString(request);
            
            var newName = string.Concat(controllerName, "V", version);
            
            HttpControllerDescriptor versionedDescriptor;
            
            if(controllers.TryGetValue(newName, out versionedDescriptor))
            {
                return versionedDescriptor;
            }
            
            return descriptor;
        }
        
        return null;
        
    }
    
    //從QueryString中獲取版本 
    private string GetVersionFromQueryString(HttpRequestMessage request)
    {
        var query = HttpUtility.ParseQueryString(request.RequestUri.Query);
        var version = query["v"];
        if(version != null)
        {
            return version;
        }
        
        return "1";
    }
}

 

■ 通過Header實現版本

客戶端大致這樣請求：

User-Agent:Fiddler
Host:locahohost:8901
X-CountingKs-Version:2

 

private string GetVersionFromHeader(HttpRequestMessage request)
{
    const string HEADER_NAME = "X-CountingKs-Version";
    
    if(request.Headers.Contains(HEADER_NAME))
    {
        var header = request.Headers.GetValues(HEADER_NAME).FirstOrDefault();
        
        if(header != null)
        {
            return header;
        }
    }
    return "1";
}

 

■ 通過Accept-Header實現版本

客戶端大致這樣請求：

User-Agent:Fiddler
Host:locahohost:8901
Accept: application/json;version=2

 

private string GetVersionFromAcceptHeaderVersion(HttpRequestMessage request)
{
    var accept = request.Headers.Accept;
    
    foreach(var mime in accept)
    {
        if(mime.MediaType == "applicaiton/json")
        {
            var value = mime.Parameters
                .Where(v => v.Name.Equals("version",StringComparison.OrdinalIngoreCase))
                .FirstOrDefault();
            
            return value.Value;
        }
    }
    
    return "1";
    
}

 

■ 通過MediaType實現版本

在WebApiConfig.cs中

 

var jsonFormatter = config.Formatters.OfType<JsonMediaTypeFormatter>().FirstOrDefault();
jsonFormatter.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();

CreateMediaTypes(jsonFormatter);


private static void CreateMediaTypes(JsonMediaTypeFormatter jsonFormatter)
{
    var mediaTypes = new string[]
    {
        "application/vnd.counting,s.food.v1+json",
        "application/vnd.countingks.measure.v1+json",
        "application/vnd.countgks.measure.v2+json",
        "applicatikon/vnd.countingks.diary.v1+json",
        "application/vnd.countingks.diaryEntry.v1+json"
    };
    
    foreach(var mediaType in mediaTypes)
    {
        jsonFormatter.SupportedMeidaTypes.Add(new MediaTypeHeaderValue(mediaType));
    }
}

 

在客戶端大致這樣請求：

User-Agent:Fiddler
Host:localhost:8901
Accept:application/vnd.countingks.food.v1+json

 

private string GetVersonFromMediaType(HttpRequestMessage request)
{
    var accept = request.Headers.Accept;
    var ex = new Regex(@"application\/vnd\.countingks\.([a-z]+)\.v([0-9]+)\+json". RegexOptions.IgnoreCase);
    
    foreach(var mime in accept)
    {
        var match = ex.Match(mime.MediaType);
        if(match != null)
        {
            return match.Groups[2].Value;
        }
    }
    return "1";
}

 

■ 使用SDammann.WebApi.Versioning

https://github.com/Sebazzz/SDammann.WebApi.Versioning