Reading the binary data from a http request received via socket connection.

Question

1. I require to extract the binary data out of a http multipart request,
2. I have a server socket opened up, which can receive connections over tcp( and therefore http.)
3. I will require to read the stream, find out the "request boundary identifier", and then extract the different "request body parts".
4. From there i need to read all of the binary content and put it in a file.
5. I did some implementation to his effect. but i see that the file that i had uploaded initially if its not a text file, gets corrupted.
can you please let me know why is that happening, and a probable solution approach.
please find below the class (with a main method) I have been using to expose a server socket.
package self.services;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
public class FileServer {
     public static void main(String[] args) throws Exception {
          ServerSocket serverSocket = new ServerSocket(9999);
          String FOLDER_NAME = "uploaded_files";
          while(true) {     
               try{
                    Socket socket = serverSocket.accept();
                    InputStream is = socket.getInputStream();
                    ByteArrayOutputStream baos = new ByteArrayOutputStream();
                    BufferedReader reader = new BufferedReader(new InputStreamReader(is));
                    String currentLine;
                    int cnt = 0;
                    boolean postRequest = false;
                    String dataBoundary = null;
                    String fileName = null;
                    String yourName = null;
                    while((currentLine = reader.readLine()) != null) {
                         if(currentLine.contains("POST")) {
                              postRequest = true;
                              System.out.println("POST REQ AS EXPECTED VERY NICE");
                              continue;
                         if(!postRequest) {
                              System.out.println("NO POST REQ THIS BREAKING FLOW");
                              break;
                         } else {
                              if(currentLine.contains("Content-Type: multipart/form-data; boundary=")) {
                                   System.out.println("found a boundary value header");
                                   dataBoundary = currentLine.substring((currentLine.indexOf("boundary=") + "boundary=".length()), (currentLine.length() -1));
                                   System.out.println("boundary value = ".concat(dataBoundary));
                                   continue;
                              if(dataBoundary != null && currentLine.contains(dataBoundary)) {
                                   cnt++;
                              if(cnt == 1) {
                                   //move 3 lines
                                   if(currentLine.contains("Content-Disposition: form-data; name=\"yourName\"")){
                                        reader.readLine();//skip a line
                                   System.out.println("Your name = ".concat(yourName = reader.readLine()));
                                   continue;
                              } else if(cnt == 2) {
                                   if(currentLine.contains("Content-Disposition: form-data; name=\"sentFile\"; filename=\"")){
                                        fileName = currentLine.substring(currentLine.indexOf("filename=") + "filename=".length() + 1, currentLine.length() - 1);
                                        System.out.println("File Name = ".concat(fileName));
                                        reader.readLine();//skip a line , this would depict a content type header
                                        reader.readLine();//skip a line, this would indicate a blank line to mark the start of data.
                                        continue;
                                   } else {
                                        // write the content to os
                                        if(currentLine != null && !currentLine.contains(dataBoundary)) {
                                             baos.write(currentLine.concat("\r").getBytes());
                              } else if( cnt == 3) {
                                   System.out.println(("cnt [" + cnt).concat( "], current line [").concat(currentLine).concat("]"));
                                   break;
                    if(fileName == null ||yourName == null) {
                         System.out.println("FileServer.main() dont bother about this" );
                    } else {
                         //send a response back
                         PrintWriter pw = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()));
                         pw.write(responseMessage(yourName, fileName));
                         pw.flush();
                         //close output stream
                         pw.close();
                         //handle the request bytearray.
                         FileOutputStream fos = new FileOutputStream(FOLDER_NAME + "/" + fileName);
                         fos.write(baos.toByteArray(), 0, baos.toByteArray().length - 1);
                         fos.close();
                    //close input stream
                    reader.close();
                    socket.close();
                    baos.close();
               } catch(Exception ex) {
                    ex.printStackTrace();
     public static String responseMessage(String yourName, String fileName) {
          String response =
               "<HTML>" .concat(
               "<BODY>") .concat(
               "<P>" ).concat(
               "Mr. <FONT color=\"red\">") .concat( yourName).concat("</FONT>. Your file named <B>").concat( fileName).concat( "</B> successfully reached us." ).concat(
               "</P>") .concat(
               "</BODY>").concat(
               "</HTML>");
          return response;
}{code}
Here is a sample html file which can be used to send multipart requests to the java service.
<html>
     <body>
          <form action="http://localhost:9999" enctype="multipart/form-data" method="POST">
               Enter name :<br/>
               <input type="text" name="yourName"/>
               Enter file :<br/>
               <input type="file" name="sentFile"/>
               <br/>
               <input type="submit" value="Submit"/>
          </form>
     </body>
</html>
*Both the form elements are mandatory*
*I hope my requirement is clear. Any help regarding this will be highly appreciated.*
Regards.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                   

Answer 1

MishraC wrote:
1. I require to extract the binary data out of a http multipart request,
2. I have a server socket opened up, which can receive connections over tcp( and therefore http.)
3. I will require to read the stream, find out the "request boundary identifier", and then extract the different "request body parts".
4. From there i need to read all of the binary content and put it in a file.
5. I did some implementation to his effect. but
i see that the file that i had uploaded initially if its not a text file, gets corrupted.
can you please let me know why is that happening,Because you are using a Reader (which translates bytes to chars according to the charset encoding specified).
and a probable solution approach. Use a BufferedInputStream.