File transfer, read write through sockets in client server programming java

Question

Hello All, need help again.
I am trying to create a Client server program, where, the Client first sends a file to Server, on accepting the file, the server generates another file(probably xml), send it to the client as a response, the client read the response xml, parse it and display some data. now I am successful sending the file to the server, but could not figure out how the server can create and send a xml file and send it to the client as response, please help. below are my codes for client and server
Client side
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.BufferedReader;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileWriter;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.InetAddress;
import java.net.Socket;
import java.net.UnknownHostException;
public class XMLSocketC
     public static void main(String[] args) throws IOException
          //Establish a connection to socket
          Socket toServer = null;
          String host = "127.0.0.1";     
          int port = 4444;
          try
               toServer = new Socket(host, port);
               } catch (UnknownHostException e) {
            System.err.println("Don't know about host: localhost.");
            System.exit(1);
        } catch (IOException e) {
            System.err.println("Couldn't get I/O for the connection to host.");
            System.exit(1);
          //Send file over Socket
        //===========================================================
        BufferedInputStream fileIn = null;
          BufferedOutputStream out = null;
          // File to be send over the socket.
          File file = new File("c:/xampp/htdocs/thesis/sensorList.php");
          // Checking for the file to be sent.
          if (!file.exists())
               System.out.println("File doesn't exist");
               System.exit(0);
          try
               // InputStream to read the file
               fileIn = new BufferedInputStream(new FileInputStream(file));
          }catch(IOException eee)
               System.out.println("Problem, kunne ikke lage fil");
          try
               InetAddress adressen = InetAddress.getByName(host);
               try
                    System.out.println("Establishing Socket Connection");
                    // Opening Socket
                    Socket s = new Socket(adressen, port);
                    System.out.println("Socket is clear and available.....");
                    // OutputStream to socket
                    out = new BufferedOutputStream(s.getOutputStream());
                    byte[] buffer = new byte[1024];
                    int numRead;
                    //Checking if bytes available to read to the buffer.
                    while( (numRead = fileIn.read(buffer)) >= 0)
                         // Writes bytes to Output Stream from 0 to total number of bytes
                         out.write(buffer, 0, numRead);
                    // Flush - send file
                    out.flush();
                    // close OutputStream
                    out.close();
                    // close InputStrean
                    fileIn.close();
               }catch (IOException e)
          }catch(UnknownHostException e)
               System.err.println(e);
        //===========================================================
        //Retrieve data from Socket.
          //BufferedReader in = new BufferedReader(new InputStreamReader(toServer.getInputStream()));
          DataInputStream in = new DataInputStream(new BufferedInputStream(toServer.getInputStream()));
          //String fromServer;
        //Read from the server and prints.
          //Receive text from server
          FileWriter fr = null;
          String frn = "xxx_response.xml";
          try {
               fr = new FileWriter(frn);
          } catch (IOException e1) {
               // TODO Auto-generated catch block
               e1.printStackTrace();
          try{
               String line = in.readUTF();                    //.readLine();
               System.out.println("Text received :" + line);
               fr.write(line);
          } catch (IOException e){
               System.out.println("Read failed");
               System.exit(1);
        in.close();
        toServer.close();
public class XMLSocketS
      public static void main(String[] args) throws IOException
          //Establish a connection to socket
           ServerSocket serverSocket = null;
             try {
                 serverSocket = new ServerSocket(4444);
             } catch (IOException e) {
                 System.err.println("Could not listen on port: 4444.");
                 System.exit(1);
          Socket clientLink = null;
          while (true)
                    try
                         clientLink = serverSocket.accept();
                       System.out.println("Server accepts");
                         BufferedInputStream inn = new BufferedInputStream(clientLink.getInputStream());
                         BufferedOutputStream ut = new BufferedOutputStream(new FileOutputStream(new File("c:/xampp/htdocs/received_from_client.txt")));
                         byte[] buff = new byte[1024];
                         int readMe;
                         while( (readMe = inn.read(buff)) >= 0)
                         {     //reads from input stream, writes the file to disk
                              ut.write(buff, 0, readMe);
                         // close the link to client
                         clientLink.close();                         
                         // close InputStream
                         inn.close();                         
                         // flush
                         ut.flush();                         
                         // close OutputStream
                         ut.close();     
                         //Sending response to client     
                         //============================================================
                         //============================================================
                         System.out.println("File received");
          }catch(IOException ex)
          {System.out.println("Exception.");}
                    finally
                         try
                              if (clientLink != null) clientLink.close();
                         }catch(IOException e) {}
             clientLink.close();
             //serverSocket.close();
}

Answer 1

SERVER
import java.net.*;
import java.io.*;
public class XMLSocketS
      public static void main(String[] args) throws IOException
               //Establish a connection to socket
           ServerSocket serverSocket = null;
             try {
                 serverSocket = new ServerSocket(4545);
             } catch (IOException e) {
                 System.err.println("Could not listen on port: 4444.");
                 System.exit(1);
          Socket clientLink = null;
              try
                         clientLink = serverSocket.accept();
                     System.out.println("Server accepts the client request.....");
                     BufferedInputStream inn = new BufferedInputStream(clientLink.getInputStream());
                         BufferedOutputStream ut = new BufferedOutputStream(new FileOutputStream(new File("c:/xampp/htdocs/received_from_client.txt")));
                         byte[] buff = new byte[1024];
                         int readMe;
                         while( (readMe = inn.read(buff)) >= 0)
                         {     //reads from input stream, writes the file to disk
                              ut.write(buff, 0, readMe);
                         ut.flush();                         
                         //Sending response to client     
                         //============================================================
                         BufferedInputStream ftoC = null;
                         BufferedOutputStream outtoC = null;
                         // File to be send over the socket.
                         File file = new File("c:/xampp/htdocs/thesis/user_registration_response.xml");
                         try
                              // InputStream to read the file
                               ftoC = new BufferedInputStream(new FileInputStream(file));
                         }catch(IOException eee)
                         {System.out.println("Problem reading file");}
                         // OutputStream to socket
                         outtoC = new BufferedOutputStream(clientLink.getOutputStream());
                         byte[] buffer = new byte[1024];
                         int noRead;
                         //Checking if bytes available to read to the buffer.
                         while( (noRead = ftoC.read(buffer)) >= 0)
                              // Writes bytes to Output Stream from 0 to total number of bytes
                              outtoC.write(buffer, 0, noRead);
                         outtoC.flush();
                         //============================================================
                         System.out.println("File received");
          }catch(IOException ex)
          {System.out.println("Exception.");}
                    finally
                         try
                              if (clientLink != null) clientLink.close();
                         }catch(IOException e) {}
             clientLink.close();
             //serverSocket.close();
      }CLIENT SIDE
import java.io.*;
import java.net.*;
public class XMLSocketC
          @SuppressWarnings("deprecation")
          public static void main(String[] args)
               // Server: "localhost" here. And port to connect is 4545.
               String host = "127.0.0.1";          
               int port = 4545;
               BufferedInputStream fileIn = null;
               BufferedOutputStream out = null;
               // File to be send over the socket.
               File file = new File("c:/xampp/htdocs/thesis/sensorList.xml");
               try
                    // InputStream to read the file
                    fileIn = new BufferedInputStream(new FileInputStream(file));
               }catch(IOException eee)
               {System.out.println("Problem");}
               try
                         System.out.println("Establishing Socket Connection");
                         // Opening Socket
                         Socket clientSocket = new Socket(host, port);
                         System.out.println("Socket is clear and available.....");
                         // OutputStream to socket
                         out = new BufferedOutputStream(clientSocket.getOutputStream());
                         byte[] buffer = new byte[1024];
                         int numRead;
                         //Checking if bytes available to read to the buffer.
                         while( (numRead = fileIn.read(buffer)) >= 0)
                              // Writes bytes to Output Stream from 0 to total number of bytes
                              out.write(buffer, 0, numRead);
                         // Flush - send file
                         out.flush();
                         //=======================================
                         DataInputStream in = new DataInputStream(new BufferedInputStream(clientSocket.getInputStream()));
                         BufferedWriter outf = new BufferedWriter(new FileWriter("c:/xampp/htdocs/received_from_server.txt",true));
                         String str;
                         while(!(str = in.readLine()).equals("EOF")) {     
                              System.out.println("client : Read line -> <" + str + ">");
                              outf.write(str);//Write out a string to the file
                              outf.newLine();//write a new line to the file (for better format)
                              outf.flush();
                         //=======================================
                         // close OutputStream
                         out.close();
                         // close InputStrean
                         fileIn.close();
                         // close Socket
                         clientSocket.close();
                    }catch (IOException e)
                    {System.out.println("Exception.");}
     Could you please point where am I doing the stupid mistake, client to server is working properly, but the opposite direction is not.
Thanks