How to implement logger in this ftp server

Question

I have written a FTP Server that is used by the clients to upload xml over to the server.
Currently it is using a console and it is printing stuff out on a console.
I have tried a lot to implement a logger class so that all console messages get written to a file.
But it has not been working out at all.
I would deeply appreciate if all you java gurus out there could modify the code given below to correctly log messages to a log file.
Please do Explain if possible ...I will try to rectify this issue in several other applications i developed as well.
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

Stick a
Logger log = Logger.getLogger( "me ftp server" );at the top.
Checn Sys.out.println to log.info( ... )
Add a logging prefs file.
http://java.sun.com/j2se/1.4.2/docs/guide/util/logging/overview.html