在ASP.NET Web API中，当我们的API发生改变，就涉及到版本问题了。如何实现API的版本呢？
1、通过路由设置版本
最简单的一种方式是通过路由设置，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、通过HttpControllerSelector
通过更改HttpControllerSelector也可以实现。
首先写一个继承 DefaultHttpControllerSelector的类。
using System.Web.http.Dispatcher public class CountingKsControllerSelector : DefaultHttpControllerSelector
{
private HttpConfiguraion _config; public CountgKsControllerSelector(HttpConfiguraiton cofig) : base(config)
{
_config = config;
} //设计就是返回HttpControllerDesriptor的过程
public override System.Web.Http.Controllers.HttpControllerDescriptor SelectController(HttpRequestMessage request)
{
//获取所有的controller键值集合
var controllers = GetControllerMapping(); //获取路由数据
var routeData = request.GetRouteData(); //从路由中获取当前controller的名称
var controllerName = (string)routeData.Values["controller"]; HttpControllerDescriptor descriptor; if(controllers.TryGetValue(controllerName, out descriptor))
{
var version = ""; //从QueryString中获取版本
var newName = string.Concat(controllerName, "V", version); HttpControllerDescriptor versionedDescriptor; if(controllers.TryGetValue(newName, out versionedDescriptor))
{
return versionedDescriptor;
} return descriptor;
} return null; }
}
在WebApiConfig.cs注册自定义的ControllerSelector
config.Services.Replace(typeof(IHttpControllerSelector), new CountingKsControllerSelector(config) );
以上是大致的实现思路。具体来说可以通过如下几种方式实现。
■ 通过Query String实现版本
客户端大致这样请求：
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;
} //设计就是返回HttpControllerDesriptor的过程
public override System.Web.Http.Controllers.HttpControllerDescriptor SelectController(HttpRequestMessage request)
{
//获取所有的controller键值集合
var controllers = GetControllerMapping(); //获取路由数据
var routeData = request.GetRouteData(); //从路由中获取当前controller的名称
var controllerName = (string)routeData.Values["controller"]; HttpControllerDescriptor descriptor; if(controllers.TryGetValue(controllerName, out descriptor))
{
//var version = "2"; //从QueryString中获取版本
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; } //从QueryString中获取版本
private string GetVersionFromQueryString(HttpRequestMessage request)
{
var query = HttpUtility.ParseQueryString(request.RequestUri.Query);
var version = query["v"];
if(version != null)
{
return version;
} return "";
}
}
■ 通过Header实现版本
客户端大致这样请求：
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 "";
}
■ 通过Accept-Header实现版本
客户端大致这样请求：
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 ""; }
■ 通过MediaType实现版本
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));
}
}
在客户端大致这样请求：
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[].Value;
}
}
return "";
}
■ 使用SDammann.WebApi.Versioning
https://github.com/Sebazzz/SDammann.WebApi.Versioning