// Import Servlet Libraries
import javax.servlet.*;
import javax.servlet.http.*;

// Import Java Libraries
import java.io.*;
import java.util.*;
import java.lang.*;

public class FileLoad extends HttpServlet {

   String authorDir ="/export/home/faculty/ofut/public_html/FileLoad/";

   /** **********************************************************
    *  doPost()
    ************************************************************ */
   public void doPost (HttpServletRequest req, HttpServletResponse res)
      throws ServletException, IOException
   {
      ServletOutputStream out = null;
      DataInputStream in = null;
      FileOutputStream fileOut = null;

      try
      {
         /* set content type of reponse and get handleto output
            stream in case weare unable to redirect client */
         res.setContentType("text/plain");
         out = res.getOutputStream();
      }
      catch(IOException e)
      {
         //print error message to standard out
         System.out.println("Error getting output stream");
         System.out.println("Error description: " + e);
         return;
      }

      try
      {
         /* get content type of client request */
         String contentType = req.getContentType();

         if(contentType != null && contentType.indexOf("multipart/form-data") != -1)
         {
            //open input stream from client to capture upload file
            in = new DataInputStream(req.getInputStream());

            //get length of content data
            int formDatalength = req.getContentLength();

            //check for maximum size violation
/*            if(formDatalength > MAX_SIZE)
            {
               out.println("Sorry, file is too large to upload");
               out.flush();
               return;
            }
*/
            //allocate a byte array to store content data
            byte dataByte[] = new byte[formDatalength];

            //read file into byte array
            int bytesRead = 0;
            int totalBytesRead = 0;


            out.println("dataByte length: " + dataByte.length);



/*            while(totalBytesRead < formDatalength)
            {
               bytesRead = in.read(dataByte, totalBytesRead, formDatalength);

               //keep track of total bytes read from input stream
               totalBytesRead += bytesRead;


               out.println("totalBytesRead: " + totalBytesRead);
            }
*/
            while(totalBytesRead < formDatalength)
            {
               dataByte[totalBytesRead] = in.readByte();

               //keep track of total bytes read from input stream
               totalBytesRead ++;
            }
            out.println("totalBytesRead: " + totalBytesRead);

            //create string fom byte array for easy manipulation
            String file = new String(dataByte);
            //since byte is store is in string, release memory
            dataByte = null;

            //get boundary value
            int lastIndex = contentType.lastIndexOf("=");
            String boundary = contentType.substring(lastIndex+1, contentType.length());

            //get filename of upload file
            String saveFile = file.substring(file.indexOf("filename=\"") + 10);
            saveFile = saveFile.substring(0, saveFile.indexOf("\n"));
            saveFile = saveFile.substring(saveFile.lastIndexOf("\\") + 1, saveFile.indexOf("\""));


            out.println("saveFile: " + saveFile);

            //remove boundary markers and other multipart/form-data tags
            //from beginning of upload file section
            int pos; //position in upload file
            //find position of upload file section of request
            pos = file.indexOf("filename=\"");
            //find position of content-disposition line
            pos = file.indexOf("\n", pos) + 1;
            //find position of content-type line
            pos = file.indexOf("\n", pos) + 1;
            //find position of blank line
            pos = file.indexOf("\n", pos) + 1;

            //find location of the next boundary marker
            //(mark of the end of the upload file)
            int boundaryLocation =file.indexOf(boundary, pos) - 4;

            //upload file lies between pos and boundaryLocation
            file = file.substring(pos, boundaryLocation);

            //build the full path of the upload file
            String fileName = new String(authorDir + saveFile);

            out.println("fileName: " + fileName);

            //instantiate file output stream
            fileOut = new FileOutputStream(fileName);

            //write the string to the file as a byte array
            fileOut.write(file.getBytes(), 0, file.length());
         }
         else //request is not multipart/form-data
         {
            out.println("Request not multipart/form-data.");
         }
      }
      catch(Exception e)
      {
         try
         {
            System.out.println("Error in doPost: " + e);
            out.println("An unexpected error has occured.");
            out.println("Error description: " + e);
         }
         catch(Exception f) {}
      }
      finally
      {
         try
         {
            fileOut.close();
         }
         catch(Exception f) {}
         try
         {
            in.close();
         }
         catch(Exception f) {}
         try
         {
            out.close();
         }
         catch(Exception f) {}
      }
   }
}