将 POST 请求从 asp.net 核心控制器转发到不同的 URL

Question

我想在不使用中间件的情况下将传入的 POST 请求"按原样"转发到我的 asp.net 核心控制器(包括标头、正文、来自数据)到不同的 URL。

我为 asp.net 找到了一个这样做的例子：https://philsversion.com/2012/09/06/creating-a-proxy-with-apicontroller/

但这不适用于 asp.net 核心，因为调用 返回等待 HTTP。发送异步(这个。请求); asp.net 核心接受 HttpRequestMessage，请求对象类型为 HttpRequest。

我还找到了一些代码，它从HttpRequest创建HttpRequestMessage，请参阅：将Microsoft.AspNetCore.Http.HttpRequest转换为HttpRequestMessage

使用此代码，接收终结点(我转发到的终结点)获取 Body，但不获取 Form 字段。

检查类 HttpRequestMessage 我发现它不包含 FormFields 的属性。

[Microsoft.AspNetCore.Mvc.HttpPost]
[NrgsRoute("api/redirect-v1/{key}")]
public async Task<HttpResponseMessage> Forward(
[FromUri] string key,
CancellationToken cancellationToken)
{
// the URL was shortened, we need to get the original URL to which we want to forward the POST request
var url = await _shortenUrlService.GetUrlFromToken(key, cancellationToken).ConfigureAwait(false);
using (var httpClient = new HttpClient())
{
var forwardUrl = new Uri(url);
Request.Path = new PathString(forwardUrl.PathAndQuery);
// see: https://stackoverflow.com/questions/45759417/convert-microsoft-aspnetcore-http-httprequest-to-httprequestmessage
var requestMessage = Request.ToHttpRequestMessage();
return await httpClient.SendAsync(requestMessage, cancellationToken);
// Problem: Forwards header and body but NOT form fields
}
}

预期结果是在我的接收端点上我有相同的 -头 -身体 - 表单字段 与原始开机自检请求一样。

Answer 1

我最终做了以下事情：

[HttpPost]
[NrgsRoute("api/redirect-v1/{key}")]
public async Task<RedirectResult> Forward(string key, CancellationToken cancellationToken)
{
var url = await _shortenUrlService.GetUrlFromToken(key, cancellationToken).ConfigureAwait(false);
if (string.IsNullOrEmpty(url))
throw new BadRequestException($"Could not create forward URL from parameter {key}", "redirect-error");
using (var httpClient = new HttpClient())
{
var forwardUrl = new Uri(url);
Request.Path = new PathString(forwardUrl.PathAndQuery);
HttpResponseMessage responseMessage;
if (Request.HasFormContentType)
responseMessage = await ForwardFormData(key, httpClient, forwardUrl, cancellationToken);
else
responseMessage = await ForwardBody(key, httpClient, cancellationToken);
var queryParams = forwardUrl.GetQueryStringParams();
var lUlr = queryParams["lurl"];
return new RedirectResult(lUlr);
}
}
private async Task<HttpResponseMessage> ForwardFormData(string key, HttpClient httpClient, Uri forwardUrl, CancellationToken cancellationToken)
{
var formContent = new List<KeyValuePair<string, string>>();
HttpResponseMessage result;
if (Request.ContentType == "application/x-www-form-urlencoded")
{
foreach (var formKey in Request.Form.Keys)
{
var content = Request.Form[formKey].FirstOrDefault();
if (content != null)
formContent.Add(new KeyValuePair<string, string>(formKey, content));
}
var formUrlEncodedContent = new FormUrlEncodedContent(formContent);
result = await httpClient.PostAsync(forwardUrl, formUrlEncodedContent, cancellationToken);
}
else
{
var multipartFormDataContent = new MultipartFormDataContent();
foreach (var formKey in Request.Form.Keys)
{
var content = Request.Form[formKey].FirstOrDefault();
if (content != null)
multipartFormDataContent.Add(new StringContent(content), formKey);
}
result = await httpClient.PostAsync(forwardUrl, multipartFormDataContent, cancellationToken);
}
return result;
}
private async Task<HttpResponseMessage> ForwardBody(string key, HttpClient httpClient, CancellationToken cancellationToken)
{
// we do not have direct access to Content, see: https://stackoverflow.com/questions/41508664/net-core-forward-a-local-api-form-data-post-request-to-remote-api
var requestMessage = Request.ToHttpRequestMessage();
return await httpClient.SendAsync(requestMessage, cancellationToken);
}