Calling rest API with HTTPWebRequest

Question

I am calling a rest API as follows. I wonder if there are ways to improve/optimize the code. Should I add time-out or cancellation token? Any help would be appreciated.

public static async Task<HttpResponseMessage> CallTestRazer(GameRequest gameRequest, string url)
{
    //FormUrlEncodedContent content = null;
    HttpResponseMessage response = null;

    //Transform GameRequest into ProductDTO
    var config = new MapperConfiguration(cfg => { cfg.CreateMap<GameRequest, ProductRequestDto>(); });
    var iMapper = config.CreateMapper();
    var productRequest = iMapper.Map<GameRequest, ProductRequestDto>(gameRequest);

    if (url == "Product/")
    {
        try
        {

            //HTTPWebRequest
            var request = (HttpWebRequest) WebRequest.Create("http://test.com/store/" + url);
            request.ContentType = "application/x-www-form-urlencoded";
            request.Method = "POST";

            var keyValueContent = productRequest.ToKeyValue();
            var formUrlEncodedContent = new FormUrlEncodedContent(keyValueContent);
            var urlEncodedString = await formUrlEncodedContent.ReadAsStringAsync();

            using (var streamWriter = new StreamWriter(await request.GetRequestStreamAsync()))
            {
                streamWriter.Write(urlEncodedString);
            }

            HttpWebResponse httpResponse = (HttpWebResponse) (await request.GetResponseAsync());

            response = new HttpResponseMessage
            {
                StatusCode = httpResponse.StatusCode,
                Content = new StreamContent(httpResponse.GetResponseStream()),
            };



            return response;

        }
        catch (Exception ex)
        {
            Console.WriteLine(ex);
            throw ;
        }
    }
    else
    {
        try
        {

            //HTTPWebRequest
            var request = (HttpWebRequest)WebRequest.Create("http://test.com/store/" + url);
            request.ContentType = "application/x-www-form-urlencoded";
            request.Method = "POST";

            var keyValueContent = gameRequest.ToKeyValue();
            var formUrlEncodedContent = new FormUrlEncodedContent(keyValueContent);
            var urlEncodedString = await formUrlEncodedContent.ReadAsStringAsync();

            using (var streamWriter = new StreamWriter(await request.GetRequestStreamAsync()))
            {
                streamWriter.Write(urlEncodedString);
            }

            HttpWebResponse httpResponse = (HttpWebResponse)(await request.GetResponseAsync());
            string json;
            using (Stream responseStream = httpResponse.GetResponseStream())
            {
                json = new StreamReader(responseStream).ReadToEnd();
            }

            response = new HttpResponseMessage
            {
                StatusCode = httpResponse.StatusCode,
                Content = new StringContent(json, System.Text.Encoding.UTF8, "application/json"),
            };



            return response;
        }
        catch (Exception e)
        {
            Console.WriteLine(e);
            throw;
        }
    }
}

Here is the ToKeyValues:

public static IDictionary<string, string> ToKeyValues(this object metaToken)
{
    if (metaToken == null)
    {
        return null;
    }

    JToken token = metaToken as JToken;
    if (token == null)
    {
        return ToKeyValues(JObject.FromObject(metaToken));
    }

    if (token.HasValues)
    {
        var contentData = new Dictionary<string, string>();

        foreach (var child in token.Children().ToList())
        {
            var childContent = child.ToKeyValues();
            if (childContent != null)
            {
                contentData = contentData.Concat(childContent).ToDictionary(k => k.Key, v => v.Value);
            }
        }

        return contentData;
    }

    var jValue = token as JValue;
    if (jValue?.Value == null)
    {
        return null;
    }

    var value = jValue?.Type == JTokenType.Date
        ? jValue?.ToString("o", CultureInfo.InvariantCulture)
        : jValue?.ToString(CultureInfo.InvariantCulture);

    return new Dictionary<string, string> {{token.Path, value}};
}

What happened to the rest of the code? Can you post the entire method? — t3chb0t
– t3chb0t, Commented Aug 30, 2019 at 14:58
@Fake I am curious as to why you are using HttpWebRequest yet still using HttpResponseMessage? Why not HttpClient? — Nkosi
– Nkosi, Commented Aug 30, 2019 at 18:24
@Nkosi, I was using httpclient but I got errors (System.Threading.Tasks.TaskCanceledException: A task was canceled) when I was load testing. One of the forums, somebody suggested me to use HttpWebRequest. After changing the code, the error didn't show up anymore. Long story short, I am sending HttpResponseMessage from service layer to controller. I am still using this logic in my code. — Fake Developer
– Fake Developer, Commented Aug 30, 2019 at 18:35

Walter Vehoeven · Accepted Answer · 2019-09-02 07:23:08Z

Looking at the code I would try to, make the code a bit more robust. Experiences has thought me that a perfectly good working web service sometimes fails or times-out. To capture this you can update your web.config and add the following 2 sections.

You can use this section to log Trace.WriteLine, beats Console.WriteLine as normally no one is looking at a console on a webservice and if you would the trafic would make this go so fast that you'd get an expert in speed reading

<system.diagnostics>  
  <trace autoflush="true" indentsize="4">  
    <listeners>  
      <add name="file" type="System.Diagnostics.TextWriterTraceListener" initializeData="trace.log"/>  
    </listeners>   
  </trace>  
</system.diagnostics>

You can filter what you like to capture with this section

<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"
        traceOutputOptions="ProcessId, DateTime" 
      />  
    </sharedListeners>  
    <trace autoflush="true"/>  
  </system.diagnostics>  
</configuration>

Unfortunately I do not have the time to go over all your code however here are some thoughts, I added some comments.

//update to capture lower case url as well as speed up Comparison
if (url.Equals("Product/", StringComparison.OrdinalIgnoreCase))
{
    int retryCount = 0;
    RETRY:
    try
    {
        retryCount++;

        //HTTPWebRequest works better with a URI then with a string as it would make the site more secure avoiding URL exploits
        var request = (HttpWebRequest)WebRequest.Create("http://test.com/store/" + url);

        request.ContentType = "application/x-www-form-urlencoded";
        request.Method = "POST";

        var keyValueContent = productRequest.ToKeyValue();
        var formUrlEncodedContent = new FormUrlEncodedContent(keyValueContent);
        var urlEncodedString = await formUrlEncodedContent.ReadAsStringAsync();

        using (var streamWriter = new StreamWriter(await request.GetRequestStreamAsync()))
        {
            streamWriter.Write(urlEncodedString);
        }

        HttpWebResponse httpResponse = (HttpWebResponse)(await request.GetResponseAsync());

        response = new HttpResponseMessage
        {
            StatusCode = httpResponse.StatusCode,
            Content = new StreamContent(httpResponse.GetResponseStream()),
        };

        //make sure you release the resource
        httpResponse.Close();

        //make sure you dispose this!
        return response;

    }
    catch (Exception ex)
    {
        if (retryCount < 3)
            goto RETRY;

        Console.WriteLine(ex);
        throw;
    }

}

It would be better if I add Task.Delay(retryInterval).Wait(); some delay in case there might be some network issue or etc. — Fake Developer
– Fake Developer, Commented Sep 5, 2019 at 10:29

BCdotWEB · Accepted Answer · 2019-10-02 11:30:27Z

Some quick remarks:

There's no need to convert the gameRequest to a productRequest, so the three lines that do that should be inside the if (url == "Product/").
IMHO each of the if... else blocks should be a class of their own. Considering that significant parts of those blocks are identical, those separate classes should inherit from a base class where you have a method that receives the url and the keyValueContent as parameters, and returns a httpResponse.
Don't do Console.WriteLine(ex);. Instead, use Trace combined with NLog, or pass an ILogger.

Stack Exchange Network

Calling rest API with HTTPWebRequest

2 Answers 2

You must log in to answer this question.

Hot Network Questions

Calling rest API with HTTPWebRequest

2 Answers 2

You must log in to answer this question.

Related

Hot Network Questions