ASP.NET的Web API记录入站请求内容 [英] ASP.NET Web API Logging Inbound Request Content
问题描述
我想注销的Web API请求内容 - 即JSON字符串。我实现了一个ITraceWriter类（<一个href=\"http://www.asp.net/web-api/overview/testing-and-debugging/tracing-in-aspnet-web-api\">example)并配置它，使网页API在管道调用它。但是，如果我读request.Content或复制到到流读它不适用于产生一个空模型的方法。<一href=\"http://stackoverflow.com/questions/13021089/why-is-the-body-of-a-web-api-request-read-once\">This帖子有关问题的会谈一点点。任何人都有经验注销入站Web API请求的内容，知道最好的方法是什么呢？
感谢
更新
我创建了一个简单的示例Web API项目，以排除任何东西在我的项目，我仍然看到，该模型也会因为日志为空。我要做的只是通过张贴Fidder酒店试连续几次，看看我的模型进来空。有了断点，它可能工作这就是为什么我认为有一个同步/计时问题。关于如何得到这个任何想法来工作？
标题：
的User-Agent：提琴手
主机：本地主机：56824
内容类型：应用程序/ JSON
内容长度：22
正文：
{
A：1，B：测试
}
这里的code：
控制器：
公共类ValuesController：ApiController
{
[HttpPost]
公共无效后（ValuesModel模型）
{
如果（型号== NULL）
{
的Debug.WriteLine（模式为空！）;
}
其他
{
的Debug.WriteLine（模式是不为空！）;
}
}
}
型号：
公共类ValuesModel
{
公众诠释A {搞定;组; }
公共字符串B {搞定;组; }
}
日志：
公共类APITraceLogger：DelegatingHandler
{
保护覆盖System.Threading.Tasks.Task＆LT; Htt的presponseMessage＆GT; SendAsync（HTT prequestMessage要求，System.Threading.CancellationToken的CancellationToken）
{
如果（request.Content！= NULL）
{
//这可能会导致模型为空
。request.Content.ReadAsStringAsync（）ContinueWith（S =＆GT;
{
字符串requestText = s.Result;
的Debug.WriteLine（requestText）;
}）; //所以可以这样
//request.Content.ReadAsByteArrayAsync（）
// .ContinueWith（（任务）= GT;
// {
//字符串requestText = System.Text.UTF8Encoding.UTF8.GetString（task.Result）;
//的Debug.WriteLine（requestText）;
//}）;
}
//执行的请求，这不会阻止
VAR响应= base.SendAsync（请求的CancellationToken）; // 去做：
//一旦响应异步处理，登录响应数据
//到数据库
返回响应;
}
}
在WebApiConfig类布线起来记录：
config.MessageHandlers.Add（新APITraceLogger（））;
更新乙
现在看来似乎如果我改变记录以下code添加的await，异步和返回结果现在工作。看起来似乎我不是在异步code或一个真正的计时问题什么的理解。
公共类APITraceLogger：DelegatingHandler
{
保护异步覆盖System.Threading.Tasks.Task其中p型Htt presponseMessage＆GT; SendAsync（HTT prequestMessage要求，System.Threading.CancellationToken的CancellationToken）
{
如果（request.Content！= NULL）
{ //这似乎工作 - 是它，因为它是同步的？这是一个潜在的问题？
VAR requestText =等待request.Content.ReadAsStringAsync（）;
的Debug.WriteLine（requestText）;
}
//执行的请求，这不会阻止
VAR响应= base.SendAsync（请求的CancellationToken）; // 去做：
//一旦响应异步处理，登录响应数据
//到数据库
返回response.Result;
}
}
由于菲利普在该职位ReadAsStringAsync或ReadAsByteArrayAsync方法提到内部缓存请求的内容。这意味着，即使你传入的请求的流类型是一个非缓冲流，你可以放心地做一个ReadAsStringAsync / ReadAsByteArrayAsync在例如消息处理程序，并且也期望模型绑定做工精细。
在默认情况下，请求的流在两个虚拟主机提供商和selfhost案件缓冲。但是，如果你想检查是否使用ReadAsStringAsync / ReadAsByteArrayAsync和型号招投标工作正常，即使在非缓冲模式下，您可以执行以下操作来强制非缓冲模式：
公共类CustomBufferPolicySelector：WebHostBufferPolicySelector
{
公众覆盖布尔UseBufferedInputStream（对象hostContext）
{
//注意：默认情况下，请求流始终处于缓冲模式。
//返回base.UseBufferedInputStream（hostContext）; 返回false;
}
}config.Services.Replace（typeof运算（IHostBufferPolicySelector），新CustomBufferPolicySelector（））;
仅供参考......上述政策选择仅适用于目前的虚拟主机。如果你想做好SelfHost类似的试验，然后执行以下操作：
//注意：默认情况下，传输模式是TransferMode.Buffered
config.TransferMode = System.ServiceModel.TransferMode.StreamedRequest;
完成上述职务的更新A：
您可以修改您的处理程序如下图所示：
公共类LoggingHandler：DelegatingHandler
{
保护覆盖异步任务＆LT; Htt的presponseMessage＆GT; SendAsync（HTT prequestMessage请求的CancellationToken的CancellationToken）
{
如果（request.Content！= NULL）
{
字符串requestContent =等待request.Content.ReadAsStringAsync（）;
} HTT presponseMessage响应=等待base.SendAsync（请求的CancellationToken）; 如果（response.Content！= NULL）
{
字符串responseContent =等待response.Content.ReadAsStringAsync（）;
} 返回响应;
}
}
I’m trying to log out Web API Request Content – i.e. the json string. I implemented an ITraceWriter class (example) and configured it so that Web API calls it in the pipeline. But if I read the request.Content or copy into to a stream to read it is not available for the method resulting in a null model. This post talks about that issue a little. Anyone have experience logging out inbound Web API request content and know what the best approach is?
Thanks
Update A
I created a simple sample Web API project to rule out anything in my project and I still see that the model will be null because of logging. I simply test a few times in a row by posting via Fidder and see my model comes in null. With breakpoints in place, it might work which is why I think there is a sync/timing issue. Any thoughts on how to get this to work?
Header:
User-Agent: Fiddler
Host: localhost:56824
Content-Type: application/json
Content-Length: 22
Body:
{
"A":1,"B":"test"
}
Here's the code:
Controller:
public class ValuesController : ApiController
{
[HttpPost]
public void Post(ValuesModel model)
{
if (model == null)
{
Debug.WriteLine("model was null!");
}
else
{
Debug.WriteLine("model was NOT null!");
}
}
}
Model:
public class ValuesModel
{
public int A { get; set; }
public string B { get; set; }
}
Logger:
public class APITraceLogger : DelegatingHandler
{
protected override System.Threading.Tasks.Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)
{
if (request.Content != null)
{
// This can cause model to be null
request.Content.ReadAsStringAsync().ContinueWith(s =>
{
string requestText = s.Result;
Debug.WriteLine(requestText);
});
// and so can this
//request.Content.ReadAsByteArrayAsync()
// .ContinueWith((task) =>
// {
// string requestText = System.Text.UTF8Encoding.UTF8.GetString(task.Result);
// Debug.WriteLine(requestText);
// });
}
// Execute the request, this does not block
var response = base.SendAsync(request, cancellationToken);
// TODO:
// Once the response is processed asynchronously, log the response data
// to the database
return response;
}
}
Wiring up logger in WebApiConfig class:
config.MessageHandlers.Add(new APITraceLogger());
Update B
It seems like it is now working if I change the logger to the following code adding the await, async and returning the result. Seems like something I'm not understanding in the async code or truly a timing issue or something.
public class APITraceLogger : DelegatingHandler
{
protected async override System.Threading.Tasks.Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)
{
if (request.Content != null)
{
// This does seem to work - is it because it is synchronous? Is this a potential problem?
var requestText = await request.Content.ReadAsStringAsync();
Debug.WriteLine(requestText);
}
// Execute the request, this does not block
var response = base.SendAsync(request, cancellationToken);
// TODO:
// Once the response is processed asynchronously, log the response data
// to the database
return response.Result;
}
}
As Filip mentions in that post ReadAsStringAsync or ReadAsByteArrayAsync methods buffer the request content internally. This means that even if your incoming request's stream type is a non-buffered stream, you could safely do a ReadAsStringAsync/ReadAsByteArrayAsync at a message handler for example, and also expect the model binding to work fine.
By default, a request's stream is buffered in both webhost and selfhost cases. But if you would like to check if using ReadAsStringAsync/ReadAsByteArrayAsync and model biding works fine even in non-buffered mode, you can do the following to force non-buffered mode:
public class CustomBufferPolicySelector : WebHostBufferPolicySelector
{
public override bool UseBufferedInputStream(object hostContext)
{
//NOTE: by default, the request stream is always in buffered mode.
//return base.UseBufferedInputStream(hostContext);
return false;
}
}
config.Services.Replace(typeof(IHostBufferPolicySelector), new CustomBufferPolicySelector());
Just FYI...the above policy selector works only for Web Host currently. If you would like to do a similar test in SelfHost, then do the following:
//NOTE: by default, the transfer mode is TransferMode.Buffered
config.TransferMode = System.ServiceModel.TransferMode.StreamedRequest;
After Update B of the post above:
You could modify your handler like below:
public class LoggingHandler : DelegatingHandler
{
protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
if (request.Content != null)
{
string requestContent = await request.Content.ReadAsStringAsync();
}
HttpResponseMessage response = await base.SendAsync(request, cancellationToken);
if (response.Content != null)
{
string responseContent = await response.Content.ReadAsStringAsync();
}
return response;
}
}
这篇关于ASP.NET的Web API记录入站请求内容的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
