httpWebRequest.AutomaticDecompression does not set "Accept_Encoding: gzip" header - c#

I am using a web service reference in my .net 3.0 app and I'm trying to set up gzip decoding.
When I use SoapUI the responses are compressed with gzip because the the header 'Accept-Encoding: gzip,deflate' is set in the request. When my .net request is sent it does not have this header so the server is not compressing the response.
I found this link which describes exactly what I want to do. I implemented the code and verified with the debugger that it was being executed on every request, but it is still not adding the 'Accept-Encoding:gzip' header.
Next I added the header manually in the class from the link.
httpWebRequest.Headers.Add("Accept-Encoding", "gzip");
Finally I received a compressed response from the server! But no, now I get an malformed xml exception which I'm pretty sure is because the response is not being decompressed even though the following is set by using the class from the link.
httpWebRequest.AutomaticDecompression = DecompressionMethods.GZip;;
I cannot understand what is going wrong.

Ok I figured out a solution to my problem.
Since I am using a web reference you have to set EnableDecompression = true on the web reference object.
So the solution is something like this
var client = new ReferredService
{
EnableDecompression = true
}
where ReferredService is the web reference name.

Related

API GET Request Returns HTML/Text instead of JSON

This is my first time working with a RESTful API and Xamarin and etc. I have so far made a simple REST API. I have written a GET call to it that, if I write http://localhost:[num]/api/Name, it will return a JSON file of the matching Emu's information. I have tested this with Postman, so I know that it works.
I have now written an app that will call this API in order to catch this information and then display it. So far, I've got it connected to the server hosting my API, but I'm unable to get it to return JSON. Instead it seems to be returning text/HTTP.
From what I've searched up on previous Stack Overflow threads, it seems that I was missing Headers requesting that reply be in a JSON format. When I added in code that was on the official .NET documentation on Microsoft's website, it gave me issues with my Json Deserialiser. I have also added in the information in the header to make sure that it returns json.
Here is the code for the function:
async private void Submit_OnClicked(object sender, EventArgs e)
{
var nameValue = EmuName.Text;
var baseAddr = new Uri("http://my_url/HelloEmu/");
var client = new HttpClient { BaseAddress = baseAddr };
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
string url = (string)nameValue;
var returnedJson = await client.GetStringAsync(url);
Models.EmuItemModel MyEmu = JsonConvert.DeserializeObject<Models.EmuItemModel>(returnedJson);
ReturnedName.Text = MyEmu.Name;
ReturnedAge.Text = MyEmu.Age.ToString();
ReturnedWeight.Text = MyEmu.Weight.ToString();
My code actually faults on the line ReturnedWeight.Text = MyEmu.Weight.ToString()
But I'm guessing the more majour issue is occuring during deserialisng the object, because it seemingly "skips" over the preceeding two lines when I run it in the debugger.
When I run it in Visual Studio 2019, the value of "returnedJson" is this:
"<html><head><meta http-equiv=\"refresh\" content=\"0;url=http://lookup.t-mobile.com/search/?q=http://my_url/HelloEmu/Keith&t=0\"/></head><body><script>window.location=\"http://lookup.t-mobile.com/search/?q=\"+escape(window.location)+\"&r=\"+escape(document.referrer)+\"&t=0\";</script></body></html>"
I think this is an HTML output. I would love any hints about what on earth I'm doing wrong!
EDIT: Since it almost seems like the HTML is returning an error message, perhaps it could do with my url??? I've published the website using the File system method. So to access the API in Postman I'll use http://localhost:[port]/api/values, calling my website in a regular ol' browser makes it go http://my_url/HelloEmu. I get a 403 "no directory" method in return...
EDIT: Here is the Postman code:
enter image description here
Usually it happens because there are missing headers or some other malformed request, Download RestSharp DLL from NuGet, and then you can use the following, in postman, go to "Code":
And choose C# you will see a code snippet (Example):

Put call works in PostMan but not in RestSharp: Getting a bad request

I want to call an endpoint with a Put command.
In Postman
I can put example https://example.com/customers/106. I then add a body of type application/json (under raw).
When I Put this body to the endpoint, I get a 200 OK.
The endpoint I use requires two custom headers and a content-type, which I have made under headers. So I add three headers: X-AppSecretToken, X-AgreementGrantToken and the Content-Type (to application/json).
In RestSharp
Here I use the following. The putstr is the exact same body I Put as I do in Postman:
var restclient = new RestSharp.RestClient("https://example.com");
var request = new RestRequest("/customers/" + customerId, Method.PUT);
request.AddHeader("X-AppSecretToken", systemToken);
request.AddHeader("X-AgreementGrantToken", userToken);
request.AddHeader("Accept", "application/json");
request.AddJsonBody(putstr);
var response = restclient.Execute(request);
Now, when I do this, I get the following response which is a custom error from the API I am calling:
"{\"message\":\"Error converting value SOME STUFF}}\\\" to type 'eco.rest.Models.Customer'. Path '', line 1, position 605.\",\"errorCode\":\"E00500\",\"developerHint\":\"The JSON payload could not be parsed. The error message should give you a good indication of where the error is located. One common reason for this error is a missing '{' or a '}' in your payload.\",\"logId\":\"123fc6fb4964a141f612ae8ae7571446\",\"httpStatusCode\":400,\"logTime\":\"2018-05-20T21:56:56\"}"
How to fix?
Normally, I'd never ask this question. If someone else asked, I would say: open Fiddler or a similar tool and see how requests are different.
I have some troubles with this, because it's HTTPS.
When I debug through my code, I simply don't see the call inside Fiddler. I also installed Charles, but also no luck. Not sure what the problem is.
However, I thought that someone who reads this can probably come up with the problem. My own assumptions are I maybe have added the headers in a wrong way, the JSON body is encoded different or similar - but I am really unsure how to move on. I hope someone can help!
Your putstr value seems to be a JSON value.
AddJsonBody will convert this JSON value into another JSON value.
You should use the original object instead of putstr.

Can I change the content of an incoming HTTP request using a HTTP Module?

I'm trying to extend my REST service (built using WCF/webHttpBinding) so that clients can upload gzipped data. I'm not sure what the best way to accomplish this but I thought it would be fairly easy by adding a HTTP module which will decompress the data if Content-Encoding for the incoming request is set to gzip.
So I created an class deriving from IHttpModule with the following implementation:
private void OnBeginRequest(object sender, EventArgs e)
{
var app = (HttpApplication) sender;
var context = app.Context;
var contentEncoding = context.Request.Headers["Content-Encoding"];
if (contentEncoding == "gzip")
{
// some debug code:
var decompressedStream = new GZipStream(context.Request.InputStream, CompressionMode.Decompress);
var memoryStream = new MemoryStream();
decompressedStream.CopyTo(memoryStream);
memoryStream.Seek(0, SeekOrigin.Begin);
var streamReader = new StreamReader(memoryStream);
string msg = streamReader.ReadToEnd();
context.Request.InputStream.Seek(0, SeekOrigin.Begin);
app.Request.Filter = //new TestFilterStream(app.Request.Filter);
new System.IO.Compression.GZipStream(
app.Request.Filter, CompressionMode.Decompress);
}
}
The issue I'm seeing is that the GZipStream decompression is never actually performed. I've confirmed that the incoming data is in fact gzip'd (the msg-variable contains the proper data). I've also tried creating my own stream class (TestFilterStream) above and assign that to app.Request.Filter and I've confirmed that no members on the stream class is actually called by ASP.NET. So it seems like while it's possible to specify a filter, that filter isn't actually used.
Isn't HttpApplication.Request.Filter actually used?
I tried setting the Request Filter in two ways:
Using a HttpModule
Setting it in the start of Application_BeginRequest() (Global.asax)
Both with the same results (VS2012 web project + IISExpress):
If there is no input data (GET request or similar), the Filter.Read is not invoked
In case of a POST with actual data, the filter is executed and the web service gets the filtered data
Even if I read from the Request.InputStream before the Filter is set, I still get the filter triggered from my service code.
I have no easy way of testing with Gzippet input, so I have not tried if the actual filter works. However, I know it is getting triggered, since I get an error from GZipStream while it attempts to look for the input.
Perhaps you are having other HttpModules or Filters that disrupt your input or control flow?
This post proposes a method similar to yours, but also states the following, which may be causing some side effects (my tests were not using WCF):
"It appears that this approach trigger a problem in WCF, as WCF relies on the original Content-Length and not the value obtained after decompressing."
I've just done a couple of tests, and my Request.Filter stream is called into, as long as there is a request body and the request body gets read by the http handler. I'm guessing you use either a PUT or a POST, and certainly read the request body, so that shouldn't be a problem.
I suspect Knaģis' comment is correct. Have you tried without the debug code? If I dig into the HttpRequest source, I see a variable _rawContent being written to exactly once; at that same time the request filters are applied. After that the _rawContent value just gets cached, and is never updated (nor reset when a filter is added).
So by calling Request.InputStream in your debug code you are definitely preventing your filter from being applied later on. Reading the Request.Headers collection is no problem.
Are you sure, that application itself should bother?
Usually that's handled per configuration of host (IIS). So, basically, you only need to implement custom GZip support, when you host the service yourself.
You can take a look here

Translating this to a HTTP POST in C#

I am currently experimenting with the HTTP request. I have successfully managed to do get requests and I have read on doing post request with HTTP request.
Now I am trying to work with the yahoo API and in order to use the Yahoo api it states that at
The Message Management API can be used to send a message to another
Yahoo! Messenger contact. The API is very simple to use, as shown
here. Note that the contact that the message is sent to is part of the
URI, using the following format:<server>/v1/message/<network>/<contactID>
POST /v1/message/yahoo/targetYahooId?sid=msgrsessionid
Host: rcore1.messenger.yahooapis.com
Authorization: < Standard OAuth credentials >
Content-Type: application/json;charset=utf-8
Content-Length: 25
{
"message" : "Hey there"
}
Now I have an OAuth string which I obtained from get using the HttpWebRequest object.
The string is something like this
oauth_token=A%3Dvh....aRg--&oauth_token_secret=bd46a....c9239&oauth_expires_in=3600&oauth_session_handle=ALtT.....3J1N4Zg--&oauth_authorization_expires_in=784964948&xoauth_yahoo_guid=TUSKED5...NCIA
UPDATE
Now my question are as follows :
1- If I am using WebRequest object in C# what would my URI look like
2- I understand that it requires a JSON type object. How do i even know what OAuth parameters are ?
One thing you'll need to change is the content type:
request.ContentType = "application/json;charset=utf-8";
And of course, the url.
you need to change the url on the line with the url in it
you need to change the content-type line
you need to make the payload into a json string then convert it to a byte array (byteArray in the sample)
either assemble the json by hand "{ foo:'bar'}" etc or use json.net
and set the content-length
Looks like it's expecting a JSON object for the request body. Depending on the version of .NET you're using, you can either use a Javascript serializer as shown here (https://stackoverflow.com/a/7003815/939080) or JSON.NET (http://james.newtonking.com/projects/json-net.aspx) to convert your form collection into JSON output.
You are asking an open-ended question that would require people to write a bunch of code for you if you want a specific and complete answer. As others have pointed out, there are several issues that you'd need to deal with:
The JSON payload, which would be a straightforward matter of putting the JSON string in the request body via the byteArray used in the code sample.
The content type, which you would need to change as described by jrummell.
The OAuth credentials, which is a kettle of fish you'll need to read about, understand, and acquire a library for. Here's a good place to start looking for a library.

HTTPS Redirect Causing Error "Server cannot append header after HTTP headers have been sent"

I need to check that our visitors are using HTTPS. In BasePage I check if the request is coming via HTTPS. If it's not, I redirect back with HTTPS. However, when someone comes to the site and this function is used, I get the error:
System.Web.HttpException: Server
cannot append header after HTTP
headers have been sent. at
System.Web.HttpResponse.AppendHeader(String
name, String value) at
System.Web.HttpResponse.AddHeader(String
name, String value) at
Premier.Payment.Website.Generic.BasePage..ctor()
Here is the code I started with:
// If page not currently SSL
if (HttpContext.Current.Request.ServerVariables["HTTPS"].Equals("off"))
{
// If SSL is required
if (GetConfigSetting("SSLRequired").ToUpper().Equals("TRUE"))
{
string redi = "https://" +
HttpContext.Current.Request.ServerVariables["SERVER_NAME"].ToString() +
HttpContext.Current.Request.ServerVariables["SCRIPT_NAME"].ToString() +
"?" + HttpContext.Current.Request.ServerVariables["QUERY_STRING"].ToString();
HttpContext.Current.Response.Redirect(redi.ToString());
}
}
I also tried adding this above it (a bit I used in another site for a similar problem):
// Wait until page is copletely loaded before sending anything since we re-build
HttpContext.Current.Response.BufferOutput = true;
I am using c# in .NET 3.5 on IIS 6.
Chad,
Did you try ending the output when you redirect? There is a second parameter that you'd set to true to tell the output to stop when the redirect header is issued. Or, if you are buffering the output then maybe you need to clear the buffer before doing the redirect so the headers are not sent out along with the redirect header.
Brian
This error usually means that something has bee written to the response stream before a redirection is initiated. So you should make sure that the test for https is done fairly high up in the page load function.

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