Issue with Ftp Client / Server using Sockets

Question

I have developed a Ftp Client and a Ftp Server. The client Connects to the Ftp Server and sends files to the ftp server. It is a multi threaded server and can have multiple clients connecting to it.
If a client goes down...the server waits till the client comes up
Similarly the client waits if a server goes down and reconnects when the server is again up and running
i am having a strange issue here. When two clients go down and reconnect to the server...They take a long time to connect and transferring of files takes a long time...
Other wise in all other scenarios the duo work properly.
Any feedback and suggestion about this strange issue from all you java gurus out there will be deeply appreciated.
Here is the client code
import java.net.*;
import java.net.Socket;
import java.net.InetAddress;
import java.io.*;
import java.io.File;
import java.util.*;
import java.lang.*;
import java.lang.Object;
import javax.crypto.*;
import java.util.regex.*;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.KeySpec;
import java.io.InputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.File.*;
import java.nio.channels.FileLock;
public class  FTPClient {
     public static void main(String[] args) throws Exception
          Timer timer = new Timer("Test Timer");
          timer.scheduleAtFixedRate(new TimerTask()
               private int counter = 0;
                                        public void run() {
                                                                 try     {                                                                                
                                                                          System.out.println(counter++);
                                                                           Socket soc=new Socket("xxx.x.x.xx",5217);
                                                                           System.out.println("Socket Initialised.");          
                                                                           transferfileClient t=new transferfileClient(soc);
                                                                           t.SendFile();
                                                                           System.out.println("run complete.");                                                                           
                                                                      catch(Exception ex)
                                                       }, 10000, 40000);
     static class transferfileClient
     Socket ClientSoc;
     DataInputStream din;
     DataOutputStream dout;
     BufferedReader br;
     transferfileClient(Socket soc)
          try
               ClientSoc=soc;
               din=new DataInputStream(ClientSoc.getInputStream());
               dout=new DataOutputStream(ClientSoc.getOutputStream());
               br=new BufferedReader(new InputStreamReader(System.in));
          catch(Exception ex)
     //encrypto routine starts
class DesEncrypter {
       Cipher ecipher;
        Cipher dcipher;   
        // 8-byte Salt
        byte[] salt = {
            (byte)0xA9, (byte)0x9B, (byte)0xC8, (byte)0x32,
            (byte)0x56, (byte)0x35, (byte)0xE3, (byte)0x03
        // Iteration count
        int iterationCount = 19;   
        DesEncrypter(String passPhrase) {
            try {
                         // Create the key
                         KeySpec keySpec = new PBEKeySpec(passPhrase.toCharArray(), salt, iterationCount);
                         SecretKey key = SecretKeyFactory.getInstance(
                         "PBEWithMD5AndDES").generateSecret(keySpec);
                         ecipher = Cipher.getInstance(key.getAlgorithm());
                         dcipher = Cipher.getInstance(key.getAlgorithm());   
                         // Prepare the parameter to the ciphers
                         AlgorithmParameterSpec paramSpec = new PBEParameterSpec(salt, iterationCount);   
                         // Create the ciphers
                         ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
                         dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
            } catch (java.security.InvalidAlgorithmParameterException e) {
            } catch (java.security.spec.InvalidKeySpecException e) {
            } catch (javax.crypto.NoSuchPaddingException e) {
            } catch (java.security.NoSuchAlgorithmException e) {
            } catch (java.security.InvalidKeyException e) {
        // Buffer used to transport the bytes from one stream to another
        byte[] buf = new byte[1024];   
        public void encrypt(InputStream in, OutputStream out) {
            try {
                // Bytes written to out will be encrypted
                out = new CipherOutputStream(out, ecipher);   
                // Read in the cleartext bytes and write to out to encrypt
                int numRead = 0;
                while ((numRead = in.read(buf)) >= 0) {
                    out.write(buf, 0, numRead);
                out.close();
            } catch (java.io.IOException e) {
        public void decrypt(InputStream in, OutputStream out) {
            try {
                // Bytes read from in will be decrypted
                in = new CipherInputStream(in, dcipher);   
                // Read in the decrypted bytes and write the cleartext to out
                int numRead = 0;
                while ((numRead = in.read(buf)) >= 0) {
                    out.write(buf, 0, numRead);
                out.close();
            } catch (java.io.IOException e) {
}     //encryptor routine ends     
     void SendFile() throws Exception
               try
               String directoryName; 
               // File object referring to the directory.
               String[] files;        // Array of file names in the directory.        
               //directory = new File ( "C:\\FTP\\" ) ; 
               File directory1 = new File("C:\\FTP");
                    boolean successmk = directory1.mkdir();
                    if (!successmk) {
                         // Directory creation failed /Already Exists
                    File directory = new File("C:\\FTP\\ftpc");
                    boolean successmk1 = directory.mkdir();
                    if (!successmk1) {
                         // Directory creation failed /Already Exists
               //directory = new File ( "E:\\FTP-encrypted" ) ;           
            if (directory.isDirectory() == false) {
                if (directory.exists() == false)
                   System.out.println("There is no such directory!");
                else
                  System.out.println("That file is not a directory.");
            else {
                files = directory.list();
                System.out.println("Files in directory \"" + directory + "\":");
                for (int i = 0; i < files.length; i++)
                         String patternStr = "xml";
                         Pattern pattern = Pattern.compile(patternStr);
                         Matcher matcher = pattern.matcher(files);
                         boolean matchFound = matcher.find();
                                   if (matchFound) {                                   
                                   System.out.println(" " + files[i]);                                        
                                   String filename;
                                   filename=files[i];                                   
                                   File f=new File(directory,filename);
                                   FileLock lock = null;                                   
                                   FileOutputStream fos = new FileOutputStream(f, true);
                                   lock = fos.getChannel().tryLock();
                                             if (lock == null) {
                                             System.out.println(" Failed to get the file lock: means that the file is locked by other instance.");
                                             fos.close();
                                             else
                                                                 InetAddress addr = InetAddress.getLocalHost();                                                                      
                                                                           // Get IP Address
                                                                           //byte[] ipAddr = addr.getAddress();
                                                                           String ip= addr.toString();                                                                      
                                                                           // Get hostname
                                                                           //String hostname = addr.getHostName();
                                   System.out.println(" Lock Acquired.");
                                   lock.release();
                                   fos.close();
                                   dout.writeUTF("SEND");
                                        dout.writeUTF(ip);
                                   dout.writeUTF(filename);
          //String msgFromServer=din.readUTF();          
DesEncrypter encrypter = new DesEncrypter("My Pass Phrase!");
// Encrypt
          FileInputStream fino=new FileInputStream(f);
          encrypter.encrypt(fino,
new FileOutputStream("ciphertext.txt"));               
          fino.close();
          FileInputStream fin=new FileInputStream("ciphertext.txt");          
          int ch;
          do
               ch=fin.read();
               dout.writeUTF(String.valueOf(ch));
          while(ch!=-1);
          fin.close();          
          String option;
                    option=din.readUTF();
                         if((option.compareTo("Delete")==0))     
                              boolean success = (new File("ciphertext.txt")).delete();
                              boolean success1 = f.delete();
                              if (success) {
                              System.out.println("File Sent ...");
                              if (success1) {
                              System.out.println("--File deleted from Client ...");
     for (int j = 0; j < 999999999; j++){}
                                   }//pattermatch loop ends here
else
                         { //System.out.println("   " + "Not an XML file-------->" +files[i]);
for (int jb = 0; jb < 111999999; jb++){}
          }// for loop ends here for files in directory
               }//else loop ends for directory files listing               
     System.out.println("sendfile finished...");
     return;
     }               catch(Exception ex)          {ex.printStackTrace();}                    
     }//sendfile ends here     
     public void displayMenu() throws Exception
               System.out.println(" Send File");                    
                    SendFile();
                    return;          
And here is the server code...
import java.net.*;
import java.io.*;
import java.util.*;
import java.util.Date;
import java.text.SimpleDateFormat;
import java.text.DateFormat;
import java.text.Format;
import java.lang.Object;
import java.lang.*;
import javax.crypto.*;
import javax.crypto.spec.PBEKeySpec;
import javax.crypto.spec.PBEParameterSpec;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.KeySpec;
public class FTPServer
{     public static void main(String args[]) throws Exception
     {     ServerSocket soc=new ServerSocket(5217);
          System.out.println("FTP Server Started on Port Number 5217");
          while(true)
               System.out.println("Waiting for Connection ...");
               transferfile t=new transferfile(soc.accept());               
class transferfile extends Thread
     Socket ClientSoc;
     DataInputStream din;
     DataOutputStream dout;     
     transferfile(Socket soc)
     {     try
          {     ClientSoc=soc;                              
               din=new DataInputStream(ClientSoc.getInputStream());
               dout=new DataOutputStream(ClientSoc.getOutputStream());
               System.out.println("FTP Client Connected ...");
               System.out.println("External IP of Client ..." + ClientSoc.getInetAddress());
               //System.out.println("FTP Client Connected ..." + ClientSoc.getRemoteSocketAddress());
               start();               
          catch(Exception ex)
//encrypto routine starts
class DesEncrypter {
        Cipher ecipher;
        Cipher dcipher;   
        // 8-byte Salt
        byte[] salt = {
            (byte)0xA9, (byte)0x9B, (byte)0xC8, (byte)0x32,
            (byte)0x56, (byte)0x35, (byte)0xE3, (byte)0x03 };   
        // Iteration count
        int iterationCount = 19;   
       DesEncrypter(String passPhrase) {
            try {
                // Create the key
                KeySpec keySpec = new PBEKeySpec(passPhrase.toCharArray(), salt, iterationCount);
                SecretKey key = SecretKeyFactory.getInstance(
                    "PBEWithMD5AndDES").generateSecret(keySpec);
                ecipher = Cipher.getInstance(key.getAlgorithm());
                dcipher = Cipher.getInstance(key.getAlgorithm());   
                // Prepare the parameter to the ciphers
                AlgorithmParameterSpec paramSpec = new PBEParameterSpec(salt, iterationCount);   
                // Create the ciphers
                ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
                dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
            } catch (java.security.InvalidAlgorithmParameterException e) {
            } catch (java.security.spec.InvalidKeySpecException e) {
            } catch (javax.crypto.NoSuchPaddingException e) {
            } catch (java.security.NoSuchAlgorithmException e) {
            } catch (java.security.InvalidKeyException e) {
        // Buffer used to transport the bytes from one stream to another
        byte[] buf = new byte[1024];   
        public void encrypt(InputStream in, OutputStream out) {
            try {
                // Bytes written to out will be encrypted
                out = new CipherOutputStream(out, ecipher);   
                // Read in the cleartext bytes and write to out to encrypt
                int numRead = 0;
                while ((numRead = in.read(buf)) >= 0) {
                    out.write(buf, 0, numRead);
                out.close();
            } catch (java.io.IOException e) {
        public void decrypt(InputStream in, OutputStream out) {
            try {
                // Bytes read from in will be decrypted
                in = new CipherInputStream(in, dcipher);   
                // Read in the decrypted bytes and write the cleartext to out
                int numRead = 0;
                while ((numRead = in.read(buf)) >= 0) {
                    out.write(buf, 0, numRead);
                    //added later on
                    in.close();                    
                out.close();
            } catch (java.io.IOException e) {
}     //encryptor routine ends
//not implemented right now as we arent using the ftp server to download stuff...can be activated later on if we want
     void SendFile() throws Exception
          String filename=din.readUTF();
          File f=new File(filename);
          if(!f.exists())
               dout.writeUTF("File Not Found");
               return;
          else
          {     dout.writeUTF("READY");
               FileInputStream fin=new FileInputStream(f);
               int ch;
               do
                    ch=fin.read();
                    dout.writeUTF(String.valueOf(ch));
               while(ch!=-1);     
               fin.close();     
               dout.writeUTF("File Received Successfully");                                   
     String Compare(String filename) throws Exception
                    ///dout.writeUTF("entering compare");
                    String dateTempString=new String();
                    Date dateValue=new Date();
                    SimpleDateFormat formatter = new SimpleDateFormat ("hhmmss");
                    dateTempString = formatter.format(dateValue);
                    File dir1 = new File("C:\\FTPnew");
                    boolean success2 = dir1.mkdir();
                    if (!success2) {
                         // Directory creation failed /Already Exists
                    File dir = new File("C:\\FTPnew\\server");
                    boolean success = dir.mkdir();
                    if (!success) {
                         // Directory creation failed /Already Exists
                    File ftemp=new File(dir,dateTempString + filename);
                    File fnewtemp=new File(dir,"new-enc-"+filename);
                    // Create encrypter/decrypter class
                    DesEncrypter encrypter = new DesEncrypter("My Pass Phrase!");
                    FileOutputStream fout=new FileOutputStream(fnewtemp);     
                    int ch;
                    String temp;
                    do
                    {     temp=din.readUTF();
                         ch=Integer.parseInt(temp);
                         if(ch!=-1)
                              fout.write(ch);                         
                    }while(ch!=-1);
                    fout.close();
                    //dout.writeUTF("written temp en file");
                    // Decrypt
                encrypter.decrypt(new FileInputStream(fnewtemp),
                new FileOutputStream(ftemp));
                    //String Option;
                    dout.writeUTF("Delete");                    
                    System.out.println("File Upload Successfull--Duplicate file with timestamp Created");          
                    boolean success1 = fnewtemp.delete();                    
                    return "hello" ;
     void ReceiveFile() throws Exception
          String ip=din.readUTF();
          System.out.println("\tRequest Coming from Internal IP Address : "+ ip);
          String filename=din.readUTF();
          if(filename.compareTo("File not found")==0)
               return;
          // Destination directory
   File dir11 = new File("C:\\FTPnew");
                    boolean success22 = dir11.mkdir();
                    if (!success22) {
                         // Directory creation failed /Already Exists
                    File dir = new File("C:\\FTPnew\\server");
                    boolean success21 = dir.mkdir();
                    if (!success21) {
                         // Directory creation failed /Already Exists
          File f=new File(dir ,"enc-"+filename);
          File fe=new File(dir,filename);
          String option;
          if(fe.exists())
               //dout.writeUTF("File Already Exists");
               String compvalue = Compare(filename);
               //dout.writeUTF(compvalue);
               if(compvalue.compareTo("hello")==0)
                    //dout.writeUTF("Transfer Completed");
                    return;
               option=din.readUTF();
          else
               //dout.writeUTF("SendFile");
                option="Y";
               if(option.compareTo("Y")==0)
                    // Generate a temporary key.       
        // Create encrypter/decrypter class
         DesEncrypter encrypter = new DesEncrypter("My Pass Phrase!");
             FileOutputStream fout=new FileOutputStream(f);                    
                    int ch;
                    String temp;
                    do
                    {     temp=din.readUTF();
                         ch=Integer.parseInt(temp);
                         if(ch!=-1)
                              fout.write(ch);                         
                    }while(ch!=-1);
                    fout.close();                    
                    // Decrypt
                encrypter.decrypt(new FileInputStream(f),
                new FileOutputStream(fe));          
                    boolean success2 = f.delete();
                    dout.writeUTF("Delete");
                    System.out.println("File Upload Successfull");                    
               else
                    return;
     public void run()
          while(true)
               try
               String Command=din.readUTF();
               if(Command.compareTo("SEND")==0)
                    System.out.println("\tSEND Command Received ...");     
                    ReceiveFile();
                    continue;
               catch(Exception ex)
                    //System.out.println("\tClient Terminated Abnormally ...........");
                    continue;

Answer 1

Please note that this is not an FTP client and server. FTP is defined by a standard IETF protocol and this isn't it.
Then, move the following lines:
din=new DataInputStream(ClientSoc.getInputStream());
dout=new DataOutputStream(ClientSoc.getOutputStream());
System.out.println("FTP Client Connected ...");
System.out.println("External IP of Client ..." + ClientSoc.getInetAddress());
//System.out.println("FTP Client Connected ..."+ClientSoc.getRemoteSocketAddress());from the constructor into the run() method. i.e. don't do anything with the socket in the thread which handles the accept().