Comment publier du JSON sur le serveur?

Question

Voici le code que j'utilise:

 // create a request
HttpWebRequest request = (HttpWebRequest)
WebRequest.Create(url); request.KeepAlive = false;
request.ProtocolVersion = HttpVersion.Version10;
request.Method = "POST";


// turn our request string into a byte stream
byte[] postBytes = Encoding.UTF8.GetBytes(json);

// this is important - make sure you specify type this way
request.ContentType = "application/json; charset=UTF-8";
request.Accept = "application/json";
request.ContentLength = postBytes.Length;
request.CookieContainer = Cookies;
request.UserAgent = currentUserAgent;
Stream requestStream = request.GetRequestStream();

// now send it
requestStream.Write(postBytes, 0, postBytes.Length);
requestStream.Close();

// grab te response and print it out to the console along with the status code
HttpWebResponse response = (HttpWebResponse)request.GetResponse();
string result;
using (StreamReader rdr = new StreamReader(response.GetResponseStream()))
{
    result = rdr.ReadToEnd();
}

return result;
 

Quand j'exécute ceci, je reçois toujours une erreur de 500 serveur interne.

Qu'est-ce que je fais mal?

Answer 1

La façon dont je le fais et fonctionne est:

 var httpWebRequest = (HttpWebRequest)WebRequest.Create("http://url");
httpWebRequest.ContentType = "text/json";
httpWebRequest.Method = "POST";

using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
{
string json = "{\"user\":\"test\"," +
              "\"password\":\"bla\"}";

streamWriter.Write(json);
streamWriter.Flush();
streamWriter.Close();

var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
{
    var result = streamReader.ReadToEnd();
}
 

J'ai écrit une bibliothèque pour effectuer cette tâche d'une manière plus simple, c'est ici: https://github.com/ademargomes/JsonRequest

J'espère que cela aide.

Answer 2

Je sais que cela a déjà été répondu, mais la solution d'Ademar ne fonctionnait pas pour moi. Je ne suis pas tout à fait sûr de savoir pourquoi, mais je pense qu'une solution plus propre est quelque chose comme:

 var httpWebRequest = (HttpWebRequest)WebRequest.Create("");
httpWebRequest.ContentType = "text/json";
httpWebRequest.Method = "POST";

using (var streamWriter = new StreamWriter(httpWebRequest.GetRequestStream()))
{
    string json = new JavaScriptSerializer().Serialize(new
                {
                    user = "Foo",
                    password = "Baz"
                });

    streamWriter.Write(json);
    streamWriter.Flush();
    streamWriter.Close();

    var httpResponse = (HttpWebResponse)httpWebRequest.GetResponse();
    using (var streamReader = new StreamReader(httpResponse.GetResponseStream()))
    {
        var result = streamReader.ReadToEnd();
    }
}
 

Answer 3

Suite au post de Sean, il n'est pas nécessaire d'imbriquer les déclarations using. Par using le StreamWriter sera vidé et fermé à la fin du bloc; il n'est donc pas nécessaire d'appeler explicitement les méthodes Flush() et Close() :

 var request = (HttpWebRequest)WebRequest.Create("http://url");
request.ContentType = "text/json";
request.Method = "POST";

using (var streamWriter = new StreamWriter(request.GetRequestStream()))
{
    string json = new JavaScriptSerializer().Serialize(new
                {
                    user = "Foo",
                    password = "Baz"
                });

    streamWriter.Write(json);
}

var response = (HttpWebResponse)request.GetResponse();
using (var streamReader = new StreamReader(response.GetResponseStream()))
{
        var result = streamReader.ReadToEnd();
}
 

Answer 4

Si vous devez appeler en mode asynchrone, utilisez

 var request = HttpWebRequest.Create("http://www.maplegraphservices.com/tokkri/webservices/updateProfile.php?oldEmailID=" + App.currentUser.email) as HttpWebRequest;
            request.Method = "POST";
            request.ContentType = "text/json";
            request.BeginGetRequestStream(new AsyncCallback(GetRequestStreamCallback), request);

private void GetRequestStreamCallback(IAsyncResult asynchronousResult)
    {
        HttpWebRequest request = (HttpWebRequest)asynchronousResult.AsyncState;
        // End the stream request operation

        Stream postStream = request.EndGetRequestStream(asynchronousResult);


        // Create the post data
        string postData = JsonConvert.SerializeObject(edit).ToString();

        byte[] byteArray = Encoding.UTF8.GetBytes(postData);


        postStream.Write(byteArray, 0, byteArray.Length);
        postStream.Close();

        //Start the web request
        request.BeginGetResponse(new AsyncCallback(GetResponceStreamCallback), request);
    }

    void GetResponceStreamCallback(IAsyncResult callbackResult)
    {
        HttpWebRequest request = (HttpWebRequest)callbackResult.AsyncState;
        HttpWebResponse response = (HttpWebResponse)request.EndGetResponse(callbackResult);
        using (StreamReader httpWebStreamReader = new StreamReader(response.GetResponseStream()))
        {
            string result = httpWebStreamReader.ReadToEnd();
            stat.Text = result;
        }

    }
 

Answer 5

Prenez soin du type de contenu que vous utilisez:

 application/json
 

Sources :

RFC4627

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