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c#getrequestgzipcompression

How Decompress Gzipped Http Get Response in c#


Want to Decompress a Response which is GZipped Getting from an API.Tried the Below Code ,It Always return Like:-

\u001f�\b\0\0\0\0\0\0\0�Y]o........

My code is:

 private string GetResponse(string sData, string sUrl)
 {
      try
      {
           string script = null;
           try
           {
                string urlStr = @"" + sUrl + "?param=" + sData;

                Uri url = new Uri(urlStr, UriKind.Absolute);

                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(url);
                request.Method = "GET";
                request.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;

                using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
                using (StreamReader reader = new StreamReader(response.GetResponseStream()))
                {
                     script = reader.ReadToEnd();
                }      
           }
           catch (System.Net.Sockets.SocketException)
           {
                // The remote site is currently down. Try again next time. 
           }
           catch (UriFormatException)
           {
                // Only valid absolute URLs are accepted 
           }

           return script;
      }
      catch (Exception ex)
      {
           throw new Exception(ex.ToString());
      }
 }

I Found the Above Code from many References for Automatic Decompression.But Eventually,it doesn't Work for me.So as to Unzip the zipped Data I tried the Below Function,

 private string DecompressGZIP(string compressedText)
 {
      byte[] gZipBuffer = Convert.FromBase64String(compressedText);
      using (var memoryStream = new MemoryStream())
      {
           int dataLength = BitConverter.ToInt32(gZipBuffer, 0);
           memoryStream.Write(gZipBuffer, 4, gZipBuffer.Length - 4);

           var buffer = new byte[dataLength];

           memoryStream.Position = 0;
           using (var gZipStream = new GZipStream(memoryStream, CompressionMode.Decompress))
           {
                gZipStream.Read(buffer, 0, buffer.Length);
           }

           return Encoding.UTF8.GetString(buffer);
      }
 }

But,it also Failed in the First Line of code itself Because of the Following Exception:

System.FormatException: 'The input is not a valid Base-64 string as it contains a non-base 64 character, more than two padding characters, or an illegal character among the padding characters. '

As i am a Beginner,Hope You guys will Guide Me .....Thanks in advance....


Solution

  • Just Change My Function as Follows,Which is Perfectly Working For me:

    private JObject PostingToPKFAndDecompress(string sData, string sUrl)
            {
                var jOBj = new JObject();
                try
                {
    
                    try
                    {
                        string urlStr = @"" + sUrl + "?param=" + sData;
    
    
                        HttpWebRequest request = (HttpWebRequest)WebRequest.Create(urlStr);
                        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
                        Stream resStream = response.GetResponseStream();
    
                        var t = ReadFully(resStream);
                        var y = Decompress(t);
    
                        using (var ms = new MemoryStream(y))
                        using (var streamReader = new StreamReader(ms))
                        using (var jsonReader = new JsonTextReader(streamReader))
                        {
                            jOBj = (JObject)JToken.ReadFrom(jsonReader);
                        }
    
    
                    }
                    catch (System.Net.Sockets.SocketException)
                    {
                        // The remote site is currently down. Try again next time. 
                    }
    
                }
                catch (Exception ex)
                {
                    throw new Exception(ex.ToString());
                }
                return jOBj;
            }
    
            public static byte[] ReadFully(Stream input)
            {
                byte[] buffer = new byte[16 * 1024];
                using (MemoryStream ms = new MemoryStream())
                {
                    int read;
                    while ((read = input.Read(buffer, 0, buffer.Length)) > 0)
                    {
                        ms.Write(buffer, 0, read);
                    }
                    return ms.ToArray();
                }
            }
    
            public static byte[] Decompress(byte[] data)
            {
                using (var compressedStream = new MemoryStream(data))
                using (var zipStream = new GZipStream(compressedStream, CompressionMode.Decompress))
                using (var resultStream = new MemoryStream())
                {
                    zipStream.CopyTo(resultStream);
                    return resultStream.ToArray();
                }
            }