Given either a url or a HttpResponse instance, I need to send back a HttpResponse (note Response not Request) with Status code 200. I've tried a generic HttpClient.PostAsync and GetAsync, but I can't configure the status code.
This is basically a handshake for subscribing to events for a remote service. I send a Request, get an OK back from the server and now it's expecting me to reply to the OK with my own OK.
Any ideas on how to go about this? I don't have an incoming request to respond to.
var resp = new HttpResponseMessage(HttpStatusCode.OK);
// need to sent this to the url. no content necessary.
Here's some things I cannot do:
var client = new HttpClient();
var resp = await client.GetAsync(url);
-------------------
var content = new ByteArrayContent(new byte[0]);
var client = new HttpClient();
var resp = await client.PostAsync(url, content);
When you invoke HttpClient calls you are creating HttpRequestMessages. There are a number of helper methods (like some PostAsync overloads or PostAsJsonAsync) which let you pass in a plain old C# object, which it then wraps for you. These values get set in the Content property of the HttpRequestMessage, wrapped by an instance of HttpContent. You're also perfectly free to create these request messages yourself, setting the status code and content to anything you like. HttpResponseMessage (note Response, not Request) is the type you'll get back from your client call, which you can use to read the response code or data sent back to you (stored in HttpResponseMessage.Content, not to be confused with HttpRequestMessage.Content, which you would have already set).
That said, you CAN set your request content to an instance of HttpResponseMessage, but that would be a little bit odd. Generally, the objects you use for your content should be simple objects which exist simply to define the shape of your requests' body (like JSON).
This article goes over the basics pretty well: Calling a Web API from a .Net Client
You should be able to set the status directly on the HttpResponse object
Something like this...
HttpResponse().StatusCode = 200;
Related
I really am not sure what is happening.
I'm using an HttpClient to post XML content to a remote server using the PostAsync method like this:
using var content = new StringContent(payload, Encoding.UTF8, "application/xml");
using var response = await _httpClient.PostAsync(string.Empty, content);
... where payload is a string, and relative uri is empty because I just need to call base uri of httpclient.
I can perform same request in Postman and it works fine.
The issue is, for some reason httpclient actually performs a GET request instead of POST, and ignores content whatsoever:
I've checked in Postman, and it seems like it is a normal response from the server to GET request.
I've also tried
using var response = await _httpClient.SendAsync(new HttpRequestMessage(HttpMethod.Post, string.Empty){Content = content});
... and it gives the same result.
This looks like a very weird issue to me, as I've never seen http client behaving like this in the past. Could anyone please explain why is this happening? Thanks!
OK, so the issue was actually with server.
It redirected all the requests with URLs not ending with "/", like http://address.com/page to the same address but ending with "/" - http://address.com/page/, and lost the method and content in process.
As #Jimi mentioned, the RequestMessage field in HttpResponseMessage contains the info about the last request that reached the server, therefore initial request data was lost, and I mistook it for HttpClient making wrong requests.
How can I call HTTP GET using JSON parameters in content body?
I tried this:
HttpWebRequest.WebRequest.Create(_uri);
httpWebRequest.ContentType = "application/json";
httpWebRequest.Method = "GET";
httpWebRequest.Headers.Add("X-AUTH-TOKEN", _apiKey);
using(var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream())) {
string _json = "\"{\"filter\": {\"relation\": \"equals\", \"attribute\": \"state\", \"value\": \"CA\" }, \"insights\": {\"field\": \"family.behaviors\", \"calculations\": [\"fill_count\"]}}";
streamWriter.Write(_json);
streamWriter.Flush();
streamWriter.Close();
}
var httpResponse = (HttpWebResponse) httpWebRequest.GetResponse();
using(var streamReader = new StreamReader(httpResponse.GetResponseStream())) {
var result = streamReader.ReadToEnd();
}
but it throws an exception:
"Cannot send a content-body with this verb-type."
If you use .NET core, the new HttpClient can handle this. Otherwise you can use System.Net.Http.WinHttpHandler package, but it has a ton of dependencies. See answer
https://stackoverflow.com/a/47902348/1030010
for how to use these two.
I can't use .NET core and I don't want to install System.Net.Http.WinHttpHandler.
I solved it by using reflection, to trick WebRequest that it is legal to send body with a GET request (which is according to latest RFC). What I do is to set ContentBodyNotAllowed to false for HTTP verb "GET".
var request = WebRequest.Create(requestUri);
request.ContentType = "application/json";
request.Method = "GET";
var type = request.GetType();
var currentMethod = type.GetProperty("CurrentMethod", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(request);
var methodType = currentMethod.GetType();
methodType.GetField("ContentBodyNotAllowed", BindingFlags.NonPublic | BindingFlags.Instance).SetValue(currentMethod, false);
using (var streamWriter = new StreamWriter(request.GetRequestStream()))
{
streamWriter.Write("<Json string here>");
}
var response = (HttpWebResponse)request.GetResponse();
Note, however, that the attribute ContentBodyNotAllowed belongs to a static field, so when its value changes, it remains in effect for the rest of the program. That's not a problem for my purposes.
It is entirely possible, but you have to use the newer HttpClient class: https://stackoverflow.com/a/47902348/70345
Even tho it is technically allowed to send a body with Get requests, Microsoft has decided for you that you cannot do that.
This can be seen in HttpWebRequest source code:
if (onRequestStream) {
// prevent someone from getting a request stream, if the protocol verb/method doesn't support it
throw new ProtocolViolationException(SR.GetString(SR.net_nouploadonget));
}
So you need to change your verb to Put or Post or have some other workaround.
GET will only receive it.
If you need to specify parameters, please include it in url.
Or you can send JSON BODY if POST or PUT.
HTTP request methods
HTTP defines a set of request methods to indicate the desired action to be performed for a given resource. Although they can also be nouns, these request methods are sometimes referred as HTTP verbs. Each of them implements a different semantic, but some common features are shared by a group of them: e.g. a request method can be safe, idempotent, or cacheable.
GET
The GET method requests a representation of the specified resource. Requests using GET should only retrieve data.
HEAD
The HEAD method asks for a response identical to that of a GET request, but without the response body.
POST
The POST method is used to submit an entity to the specified resource, often causing a change in state or side effects on the server.
PUT
The PUT method replaces all current representations of the target resource with the request payload.
In Addition:
I found this. Long discussion has been held.
HTTP GET with request body
What this means is that it is possible to send BODY with GET, but sending a payload body on a GET request might cause some existing implementations to reject the request (such as Proxy in the middle of the route).
Please be sure to read this article carefully as there are many other points to pay attention to.
By the way, it seems that you can send GET with body using the -i option of cURL command.
Curl GET request with json parameter
So I am trying to build a program in C#. I want to send a really specific request. Exactly as I receive it in fiddler. Right now I am using fiddlers composer feature to send the request. Here is how I get the request in fiddler
How can I send it exactly as shown on the picture but in a C# console application?
Basically looking for a way to get a request in fiddler and implement it directly in to my code in the format that fiddler gives it to me.(In fiddler I can save the request in .txt format. If I could use that same .txt format to send the request then it would be really helpful)
You need to create HttpClient instance and set the headers shown in the fiddler to the same values. Hope this helps. Your URL was HTTPS hence you will need to set for certificate validation OR you will have to set avoid certificate errors on the call.
// Create a client
HttpClient httpClient = new HttpClient();
// Add a new Request Message
HttpRequestMessage requestMessage = new HttpRequestMessage(HttpMethod.Put, "https://yoursitehere/");
// Add our custom headers
requestMessage.Headers.Add("User-Agent", "User-Agent-Here");
requestMessage.Headers.Add("Connection", "MIME-Type-Here");
requestMessage.Headers.Add("Cache-Control", "value-from-fiddler");
requestMessage.Headers.Add("Accept-Language", "value-from-fiddler");
requestMessage.Headers.Add("Accept-Encoding", "value-from-fiddler");
requestMessage.Headers.Add("Accept", "value-from-fiddler");
requestMessage.Headers.Add("User-Agent", "value-from-fiddler");
// Send the request to the server
HttpResponseMessage response = await httpClient.SendAsync(requestMessage);
// Just as an example I'm turning the response into a string here
string responseAsString = await response.Content.ReadAsStringAsync();
I have been banging my head against the wall for the past 1 week now but without any success. Actually I'm writing a C# code(a web api controller action) to call another web api to make a post request with some json data payload in the request body. Syntax-wise there is nothing wrong with the code. But when I directly call the service(web api service) from web browser I get an Html form that has a multiline text box in it, rollback property (as radio button for true and false value for this property), drop down box with 2 options such as html and json (to get response in either format) and a button(for sending request to the server and making edits in the database). Now when I manually put json data inside text box and click the button on that html form edits are done successfully in the database but when programmatically(from my C# code) I send the same json data payload and make a post request edits are never done successfully rather I get an html response body through Fiddler that says status code success 200 but unable to complete operation,some parameters couldn't be recognized.
Here is my code
private static async Task<HttpResponseMessage> GeometryUpdateAsync(Feature updatedFeature, FeatureType featureType, int? objectid = null)
{
var jsonObject = new JObject();
dynamic esriId = jsonObject;
if (objectid == null)
{
objectid = updatedFeature.OBJECTID;
}
esriId.OBJECTID = objectid;
var mergedJsonString = JsonConvert.SerializeObject(new
{
geometry = JObject.Parse(updatedFeature.Geometry.ToString()),
attributes = JObject.Parse(esriId.ToString())
});
mergedJsonString = String.Format("[{0}]", mergedJsonString);
HttpResponseMessage response = null;
using (var client = new HttpClient())
{
//string arguments = "rollbackOnFailure=true&f=pjson&features=";
client.BaseAddress = new Uri("somebaseaddress");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
client.Timeout = TimeSpan.FromSeconds(500.00);
//response = await client.PostAsJsonAsync("someuri", arguments + mergedJsonString);
response = await client.PostAsync("someuri", mergedJsonString, new System.Net.Http.Formatting.JsonMediaTypeFormatter());
if (response.IsSuccessStatusCode)
{
var v = response.Content.ReadAsStringAsync().Result;
}
}
}
When I look at the request body (through fiddler while making a post request through Html form) request body looks like
features=%5B%7B%22geometry%22%3A%7B%22paths%22%3A%5B%5B%5B-91.3888577181506%2C39.703158271352621%5D%91.381838690201192%2C39.690323806398723%5D%2C%5B-91.383241723424632%2C39.689645139311914%5D%2C%5B-91.3849700567206%2C39.6888078408094%5D%2C%5B-91.3861256828518%2C39.688248198995353%5D%5D%5D%7D%2C%22attributes%22%3A%7B%22OBJECTID%22%3A21%7D%5D&gdbVersion=&rollbackOnFailure=true&f=pjson
and the request body for the post request made programmatically looks likes
"[{\"geometry\":{\"paths\":[[[-91.3888577181506,39.703158271352621],[-91.381838690201192,39.690323806398723],[-91.383241723424632,39.689645139311914],[-91.3849700567206,39.6888078408094],[-91.3861256828518,39.688248198995353]]]},\"attributes\":{\"OBJECTID\":21}}]"
Even I tried appending this
string arguments = "rollbackOnFailure=true&f=pjson&features=";
in my commented out code above (where I'm using PostAsJsonAsync) to make the request body look like as if it's coming from Html form. But no success, even I'm not sure whether the JSonFormatter takes this arguments string in to account or just leaves it while serializing/deserializing during the run time. And the post request body that I get after appending "arguments" string to Json string looks like this
"rollbackOnFailure=true&f=pjson&features=[{\"geometry\":{\"paths\":[[[-91.3877577181506,39.703158271352621],[-91.36047320856953,39.702616420911333],[-91.383241723424632,39.689645139311914],[-91.3849700567206,39.6888078408094],[-91.3861256828518,39.688248198995353]]]},\"attributes\":{\"OBJECTID\":21}}]"
But still no success, Now I'm totally running out of ideas as to how to call web api service from my C# code so that web api thinks it's coming from that Html form and end up successfully doing edits in the database programmatically. All suggestions and ideas will be highly appreciated.
The trick lies somewhere else, I was using HttpClient to simulate browser post request and get result in c#. But in this particular scenario HttpClient is of no use. I changed to HttpWebRequest after seeing a code at How to make a post call to a Web Api Action? from utlimate_programmer_BR and it did the trick, again HttpClient was a bad choice by me to get this particular thing done.
when using HttpClient and performing a PostAsync I am able to add a contract with HttpContent. for example
HttpContent content = new ObjectContent<myContractType>(MyContract, xmlFormatter);
var resp myClient.PostAsync(myUri,content).Result
when doing a GetAsync I am unable to pass a HttpContract object. That said do I need to just add the members of the contract in a query string or is there a better way to go about it?
The nature of GET requests does not provide a way to send large amounts of data to the server as might be done with a POST request. In practice, a limited amount of data can be sent in the form of headers or as part of a querystring.
There won't be a way to convert the XML data directly to a querystring, but this is an example of a request with a querystring:
var client = new HttpClient()
client.GetAsync(String.Format("http://service.example.com/api/{0}?foo=bar", id))