File service POST request examples - ABBYY Documentation

The following C# examples show how to use POST requests to work with files on the server.

Load files from the server

To load a file from the server, create a server request to AppServerURL + "/FlexiCapture12/Server/FileService/v1". Use the POST method and the application/x-www-form-urlencoded content type. Record the results to a new file. Request body and C# method:

"Action=Load" +"&sessionId=" + session + "&objectType=" + objectType + "&projectId=" + projectId + "&batchId=" + batchId + "&objectId=" + objectId + "&version=" + version + "&streamName=" + streamName
static private CredentialCache basicAuthenticationCredentialCache = null;
public static List<byte> POSTLoadFile(string AppServerURL, int session, int projectId, int batchId, int objectType, int objectId, int version, int parentId, string streamName)
       {
            List<byte> result = new List<byte>();
            HttpWebResponse response = null;
            Stream responseStream = null;
            BinaryReader reader = null;
            try
            {
                // creating the request
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(AppServerURL + "/FlexiCapture12/Server/FileService/v1");
                request.Method = "POST";
                // authentication set up when connecting to the web service
                if (basicAuthenticationCredentialCache != null)
                {
                    request.Credentials = basicAuthenticationCredentialCache;
                }
                else
                {
                    request.UseDefaultCredentials = true;
                }
                request.ContentType = "application/x-www-form-urlencoded";
                string postData = "Action=Load" +
                    "&sessionId=" + session +
                    "&objectType=" + objectType +
                    "&projectId=" + projectId +
                    "&batchId=" + batchId +
                    "&parentId=" + parentId +
                    "&objectId=" + objectId +
                    "&version=" + version +
                    "&streamName=" + streamName;
                StreamWriter writer = new StreamWriter(request.GetRequestStream());
                writer.Write(postData);
                writer.Close();                  
           
                // receiving a response
                response = (HttpWebResponse)request.GetResponse();
                responseStream = response.GetResponseStream();
                reader = new BinaryReader(responseStream);
                int responseStreamLength = 0;
                while (true)
                {
                    try
                    {
                        result.Add(reader.ReadByte());
                        responseStreamLength++;
                    }
                    catch (EndOfStreamException)
                    {
                        break;
                    }
                }
                reader.Close();
                responseStream.Close();
                response.Close();               
            }
            if (response != null) response.Close();
            if (responseStream != null) responseStream.Close();
            if (reader != null) reader.Close();
            return result;
        }

Upload files to the server

First, open an existing file and read data from it. Obtain the content string from the binary file using Encoding.Default. To save the file, create a server request to AppServerURL + "/FlexiCapture12/Server/FileService/v1". Use the POST method and the multipart/form-data content type. Request body and C# method:

"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"Action\"\r\n\r\nSave" +
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"objectType\"\r\n\r\n" + objectType +
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"sessionId\"\r\n\r\n" + session +
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"projectId\"\r\n\r\n" + projectId +
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"batchId\"\r\n\r\n" + batchId +
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"objectId\"\r\n\r\n" + objectId +
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"version\"\r\n\r\n" + version +
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"streamName\"\r\n\r\n" + streamNameInBase64 +            // name of the binary stream in Base64
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"blob\";filename=\"filename.txt\"\r\nContent-Type: application/octet-stream\r\nContent-Transfer-Encoding: binary\r\n\r\n"+                                       // the value of the filename parameter does not affect the request itself
content +                                                                        //data that is uploaded to the server
"\r\n--" + requestId + "--\r\n";
static private CredentialCache basicAuthenticationCredentialCache = null;
// the "content" string should be obtained from the binary file using Encoding.Default
        public static List<byte> POSTSaveFile(string AppServerURL, int session, int projectId, int batchId, int objectType, int objectId, int version, string streamName, string content)
        {
            List<byte> result = new List<byte>();
            HttpWebResponse response = null;
            Stream responseStream = null;
            StreamReader reader = null;
            int requestId = Environment.TickCount;
            try
            {
                // creating the request
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(AppServerURL + "/FlexiCapture12/Server/FileService/v1");
                request.Method = "POST";
                // authentication set up when connecting to the web service
                if (basicAuthenticationCredentialCache != null)
                {
                    request.Credentials = basicAuthenticationCredentialCache;
                }
                else
                {
                    request.UseDefaultCredentials = true;
                }
                request.ContentType = "multipart/form-data, boundary=" + requestId;
                byte[] streamNameInBytes = Encoding.Unicode.GetBytes(streamName);
                UnicodeEncoding UTFencofing = new UnicodeEncoding();
                string postData = "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"Action\"\r\n\r\nSave" +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"objectType\"\r\n\r\n" + objectType +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"sessionId\"\r\n\r\n" + session +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"projectId\"\r\n\r\n" + projectId +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"batchId\"\r\n\r\n" + batchId +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"objectId\"\r\n\r\n" + objectId +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"version\"\r\n\r\n" + version +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"streamName\"\r\n\r\n" + Convert.ToBase64String(streamNameInBytes) +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"blob\";filename=\"filename.txt\"\r\nContent-Type: application/octet-stream\r\nContent-Transfer-Encoding: binary\r\n\r\n";
                postData += content;
                postData += "\r\n--" + requestId + "--\r\n";
                StreamWriter writer = new StreamWriter(request.GetRequestStream(), Encoding.Default);
                writer.Write(postData);
                writer.Close();  
                // receiving a response
                response = (HttpWebResponse)request.GetResponse();
                responseStream = response.GetResponseStream(); 
                reader = new StreamReader(responseStream);
                reader.Close();
                responseStream.Close();
                response.Close();
            }
            if (response != null) response.Close();
            if (responseStream != null) responseStream.Close();
            if (reader != null) reader.Close();
            return result;
        }

Get a checksum

To get a checksum, create a server request to AppServerURL + "/FlexiCapture12/Server/FileService/v1". Use the POST method and the application/x-www-form-urlencoded content type. Request body and C# method:

"Action=Checksum" + "&sessionId=" + session + "&objectType=" + objectType + "&projectId=" + projectId + "&batchId=" + batchId + "&objectId=" + objectId + "&version=" + version + "&streamName=" + streamName
static private CredentialCache basicAuthenticationCredentialCache = null;
public static List<byte> POSTGetChecksum(string AppServerURL, int session, int projectId, int batchId, int objectType, int objectId, int version, string streamName)
        {
   List<byte> result = new List<byte>();
   HttpWebResponse response = null;
   Stream responseStream = null;
   BinaryReader reader = null;
   try
            {
                // creating the request
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(AppServerURL + "/FlexiCapture12/Server/FileService/v1");
                request.Method = "POST";
                // authentication set up when connecting to the web service
    if (basicAuthenticationCredentialCache != null)
    {
     request.Credentials = basicAuthenticationCredentialCache;
    }
    else
    {
     request.UseDefaultCredentials = true;
    }
    request.ContentType = "application/x-www-form-urlencoded";
    string postData = "Action=Checksum" +
     "&sessionId=" + session +
     "&objectType=" + objectType +
     "&projectId=" + projectId +
     "&batchId=" + batchId +
     "&objectId=" + objectId +
     "&version=" + version +
     "&streamName=" + streamName;
    StreamWriter writer = new StreamWriter(request.GetRequestStream());
    writer.Write(postData);
    writer.Close();
                // receiving a response
    response = (HttpWebResponse)request.GetResponse();
    responseStream = response.GetResponseStream();
    reader = new BinaryReader(responseStream);
    int responseStreamLength = 0;
    while (true)
    {
     try
     {
      result.Add(reader.ReadByte());
      responseStreamLength++;
     }
     catch (EndOfStreamException)
     {
      break;
     }
    }
    reader.Close();
    responseStream.Close();
    response.Close();
   }
   if (response != null) response.Close();
   if (responseStream != null) responseStream.Close();
   if (reader != null) reader.Close();
   return result;
  }

Load by parts (modify an existing file)

You can modify only a file that already exists on the server, so create the file with the POSTSaveFile method first. To modify the file, create a server request to AppServerURL + "/FlexiCapture12/Server/FileService/v1". Use the POST method and the multipart/form-data content type. Request body and C# method:

"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"Action\"\r\n\r\nAppend" +
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"objectType\"\r\n\r\n" + objectType +
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"sessionId\"\r\n\r\n" + session +
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"projectId\"\r\n\r\n" + projectId +
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"batchId\"\r\n\r\n" + batchId +
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"objectId\"\r\n\r\n" + objectId +
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"version\"\r\n\r\n" + version +
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"streamName\"\r\n\r\n" + streamNameInBase64 +
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"blob\";filename=\"filename.txt\"\r\nContent-Type: application/octet-stream\r\nContent-Transfer-Encoding: binary\r\n\r\n" +
content +                                                                                                                              //this string should be obtained the same way as in the previous example
"\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"offset\"\r\n\r\n" + offset +            //the offset from the beginning of the file, where the entry starts
"\r\n--" + requestId + "--\r\n";
static private CredentialCache basicAuthenticationCredentialCache = null;
// the "content" string should be obtained from the binary file using Encoding.Default
        // Note: you can only add to a file that already exists, meaning that you must first create a file using the POSTSaveFile method
        public static List<byte> POSTAppendFile(string AppServerURL, int session, int projectId, int batchId, int objectType, int objectId, int version, string streamName, string content, int offset)
        {
            List<byte> result = new List<byte>();
            HttpWebResponse response = null;
            Stream responseStream = null;
            StreamReader reader = null;
            int requestId = Environment.TickCount;
            try
            {
                // creating a request
                HttpWebRequest request = (HttpWebRequest)WebRequest.Create(AppServerURL + "/FlexiCapture12/Server/FileService/v1");
                request.Method = "POST";
                // authentication set up when connecting to the web service
                if (basicAuthenticationCredentialCache != null)
                {
                    request.Credentials = basicAuthenticationCredentialCache;
                }
                else
                {
                    request.UseDefaultCredentials = true;
                }
                request.ContentType = "multipart/form-data, boundary=" + requestId;
                byte[] streamNameInBytes = Encoding.Unicode.GetBytes(streamName);
                UnicodeEncoding UTFencofing = new UnicodeEncoding();
                string postData = "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"Action\"\r\n\r\nAppend" +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"objectType\"\r\n\r\n" + objectType +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"sessionId\"\r\n\r\n" + session +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"projectId\"\r\n\r\n" + projectId +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"batchId\"\r\n\r\n" + batchId +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"objectId\"\r\n\r\n" + objectId +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"version\"\r\n\r\n" + version +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"streamName\"\r\n\r\n" + Convert.ToBase64String(streamNameInBytes) +
                    "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"blob\";filename=\"filename.txt\"\r\nContent-Type: application/octet-stream\r\nContent-Transfer-Encoding: binary\r\n\r\n";
                postData += content;
                postData += "\r\n--" + requestId + "\r\ncontent-disposition: form-data; name=\"offset\"\r\n\r\n" + offset;
                postData += "\r\n--" + requestId + "--\r\n";
                StreamWriter writer = new StreamWriter(request.GetRequestStream(), Encoding.Default);
                writer.Write(postData);
                writer.Close();
                // receiving a response
                response = (HttpWebResponse)request.GetResponse();
                responseStream = response.GetResponseStream();
                // displaying the response
                reader = new StreamReader(responseStream); 
                reader.Close();
                responseStream.Close();
                response.Close();
            }
            if (response != null) response.Close();
            if (responseStream != null) responseStream.Close();
            if (reader != null) reader.Close();
            return result;
        }