.net 使用 HttpClient 时记录请求响应消息

发布于09月21日

我有一个方法可以完成下面这样的帖子

var response = await client.PostAsJsonAsync(url, entity);

if (response.IsSuccessStatusCode)
{
        // read the response as strongly typed object
        return await response.Content.ReadAsAsync<T>();
}

我的问题是如何获得从Entity对象发布的实际JSON.我想记录发布的JSON，所以不用自己做JSON序列化就可以了.

推荐答案

你可以这样做的一个例子:

注意:

LoggingHandler在将请求处理到HttpClientHandler之前截取请求，HttpClientHandler最终写入连线.
PostAsJsonAsync扩展在内部创建ObjectContent，当在LoggingHandler中调用ReadAsStringAsync()时，它会导致格式化程序

Logging handler:

public class LoggingHandler : DelegatingHandler
{
    public LoggingHandler(HttpMessageHandler innerHandler)
        : base(innerHandler)
    {
    }

    protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
    {
        Console.WriteLine("Request:");
        Console.WriteLine(request.ToString());
        if (request.Content != null)
        {
            Console.WriteLine(await request.Content.ReadAsStringAsync());
        }
        Console.WriteLine();

        HttpResponseMessage response = await base.SendAsync(request, cancellationToken);

        Console.WriteLine("Response:");
        Console.WriteLine(response.ToString());
        if (response.Content != null)
        {
            Console.WriteLine(await response.Content.ReadAsStringAsync());
        }
        Console.WriteLine();

        return response;
    }
}

Chain the above LoggingHandler with HttpClient:

HttpClient client = new HttpClient(new LoggingHandler(new HttpClientHandler()));
HttpResponseMessage response = client.PostAsJsonAsync(baseAddress + "/api/values", "Hello, World!").Result;

Output:个

Request:
Method: POST, RequestUri: 'http://kirandesktop:9095/api/values', Version: 1.1, Content: System.Net.Http.ObjectContent`1[
[System.String, mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]], Headers:
{
  Content-Type: application/json; charset=utf-8
}
"Hello, World!"

Response:
StatusCode: 200, ReasonPhrase: 'OK', Version: 1.1, Content: System.Net.Http.StreamContent, Headers:
{
  Date: Fri, 20 Sep 2013 20:21:26 GMT
  Server: Microsoft-HTTPAPI/2.0
  Content-Length: 15
  Content-Type: application/json; charset=utf-8
}
"Hello, World!"