I have a method that does a POST like below
var response = await client.PostAsJsonAsync(url, entity);
if (response.IsSuccessStatusCode)
{
// read the response as strongly typed object
return await response.Content.ReadAsAsync<T>();
}
My question is how can I obtain the actual JSON that got posted from the entity object. I would like to log the JSON that gets POSTED, so it will be nice to have that without me having to do a json serialize myself.
This question is related to
c#
.net
asp.net-mvc-4
asp.net-web-api
An example of how you could do this:
Some notes:
LoggingHandler intercepts the request before it handles it to HttpClientHandler which finally writes to the wire.
PostAsJsonAsync extension internally creates an ObjectContent and when ReadAsStringAsync() is called in the LoggingHandler, it causes the formatter
inside ObjectContent to serialize the object and that's the reason you are seeing the content in json.
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:
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!"
The easiest solution would be to use Wireshark and trace the HTTP tcp flow.
Network tracing also available for next objects (see article on msdn)
Put next lines of code to the configuration file
<configuration>
<system.diagnostics>
<sources>
<source name="System.Net" tracemode="includehex" maxdatasize="1024">
<listeners>
<add name="System.Net"/>
</listeners>
</source>
<source name="System.Net.Cache">
<listeners>
<add name="System.Net"/>
</listeners>
</source>
<source name="System.Net.Http">
<listeners>
<add name="System.Net"/>
</listeners>
</source>
<source name="System.Net.Sockets">
<listeners>
<add name="System.Net"/>
</listeners>
</source>
<source name="System.Net.WebSockets">
<listeners>
<add name="System.Net"/>
</listeners>
</source>
</sources>
<switches>
<add name="System.Net" value="Verbose"/>
<add name="System.Net.Cache" value="Verbose"/>
<add name="System.Net.Http" value="Verbose"/>
<add name="System.Net.Sockets" value="Verbose"/>
<add name="System.Net.WebSockets" value="Verbose"/>
</switches>
<sharedListeners>
<add name="System.Net"
type="System.Diagnostics.TextWriterTraceListener"
initializeData="network.log"
/>
</sharedListeners>
<trace autoflush="true"/>
</system.diagnostics>
</configuration>
See http://mikehadlow.blogspot.com/2012/07/tracing-systemnet-to-debug-http-clients.html
To configure a System.Net listener to output to both the console and a log file, add the following to your assembly configuration file:
<system.diagnostics>
<trace autoflush="true" />
<sources>
<source name="System.Net">
<listeners>
<add name="MyTraceFile"/>
<add name="MyConsole"/>
</listeners>
</source>
</sources>
<sharedListeners>
<add
name="MyTraceFile"
type="System.Diagnostics.TextWriterTraceListener"
initializeData="System.Net.trace.log" />
<add name="MyConsole" type="System.Diagnostics.ConsoleTraceListener" />
</sharedListeners>
<switches>
<add name="System.Net" value="Verbose" />
</switches>
</system.diagnostics>
Source: Stackoverflow.com