.NET Core 2.0 Web API 控制器路由（带有可选 [FromBody] 参数的 POST）用于接收 Web 挂钩

Question

目前我尝试实现一个 .NET Core 2.0 Web API web hook。

发送服务器上的 webhook 可以简单地配置为：

"endpoint": "http://localhost:50100/api/Hook"

发送服务器做了两件事：

• 在启动时，它会向定义的端点发送一个空帖子，以检查它是否存在以及支持哪些媒体类型
• 稍后，事件将作为帖子正文中的纯 json 发送到定义的端点

我实现了一个 HookController 并且知道我正面临一个（对我来说）奇怪的路由问题。

控制器实现如下：

    [Route("api/Hook")]
public class HookController : Controller
{
  protected ILogger<HookController> Logger { get; set; }

  public HookController(ILogger<HookController> logger)
  {
    Logger = logger ?? throw new ArgumentNullException(nameof(logger));
  }

  [HttpPost]
  [Produces("application/json")]
  [Consumes("application/json")]
  public IActionResult HookReceiverLookUp()
  {
    Logger.LogInformation("Hook Receiver POST lookup called");
    return Ok();
  }

  [HttpPost]
  [Produces("application/json")]
  [Consumes("application/json")]
  public IActionResult HookReceiverEvent([FromBody] JObject res)
  {
    if (res == null)
    {
      Logger.LogInformation("Lookup called (most likely because post body was null)");
      return Ok();
    }
    Logger.LogInformation("Hook Receiver event");
    return Ok();
  }

}

问题很简单：

• 如果我只有 HookReceiverLookUp 方法，服务器会在启动时识别出有效的端点，但显然此方法无法接收数据
• 如果我只有 HookReceiverEvent 方法，它可以从 POST 正文接收 json，但它不会被识别为有效端点（即使使用 [FromBody] JObject res = null）
• 如果我有这两种方法，接收 Web api 将不会以异常开始

AmbiguousActionException：匹配多个动作。以下操作匹配路线数据并满足所有约束：

---

那么这两种方法之间有什么区别（web api 说没有）以及如何将它们组合成一种方法（因为服务器配置让我只定义一种方法）？

---

我的最终解决方案

根据 Lennarts 的输入，我得到了一份可行的实施草案并正在运行。

public class HookController : Controller
{
  protected ILogger<HookController> Logger { get; set; }

  public HookController(ILogger<HookController> logger)
  {
    Logger = logger ?? throw new ArgumentNullException(nameof(logger));
  }

  //configuration url: http://localhost:[port]/api/Hook/endpoint
  [HttpPost("Endpoint")]
  public IActionResult HookReceiver([FromHeader(Name = "Content-Type")] string type)  //do not bind JObject here
  {

    if (type == null) return HookReceiverLookUp();   //check if it is the initial look up call / ignore body

    //avoiding built in / default model binder and read the body yourself if necessary
    string body;

    using (var reader = new System.IO.StreamReader(Request.Body, System.Text.Encoding.UTF8, true, 1024, true))
    {
      body = reader.ReadToEnd();
    }

    //optionally convert it to Json if you want to work with json
    JObject obj = Newtonsoft.Json.JsonConvert.DeserializeObject<JObject>(body);

    if (obj == null) return Ok(); //what else??

    return HookReceiverEvent(obj);
  }

  private IActionResult HookReceiverLookUp()
  {
    Logger.LogInformation("Hook Receiver POST lookup called");
    return Ok();
  }

  private IActionResult HookReceiverEvent(JObject res)
  {
    Logger.LogInformation("Hook Receiver POST lookup called\r\n" + res.ToString());
    return Ok();
  }

}

非常感谢 Lennart 的大力帮助和耐心。

Answer 1

你可以定义为不同的类型，使用[HttpGet] 代表HookReceiverLookUp() 和[HttpPost] 代表HookReceiverEvent([FromBody] JObject res)。

编辑

然后尝试这样的事情：

[Route("api/Hook")]
[Produces("application/json")]
[Consumes("application/json")]
public class HookController : Controller
{
    private ILogger<HookController> Logger { get; set; }

    public HookController(ILogger<HookController> logger)
    {
        Logger = logger ?? throw new ArgumentNullException(nameof(logger));
    }

    return Request.Headers.Any(
            header => header.Key == "HeaderContentType" && header.Value == "application/json")
            ? HookReceiverEvent(Request.GetBody())
            : HookReceiverLookUp();

    private IActionResult HookReceiverLookUp()
    {
        Logger.LogInformation("Hook Receiver POST lookup called");
        return Ok();
    }

    private IActionResult HookReceiverEvent(JObject res)
    {
        Logger.LogInformation("Hook Receiver event");
        return Ok();
    }
}

那么你还需要一个带有扩展方法的类。我的看起来像这样：

public static class Extensions
{
    public static JObject GetBody(this HttpRequest request)
    {
        string body;
        request.EnableRewind();

        using (var reader = new StreamReader(request.Body, Encoding.UTF8, true, 1024, true))
        {
            body = reader.ReadToEnd();
        }

        request.Body.Position = 0;
        return JsonConvert.DeserializeObject<JObject>(body);
    }
}