Java/OO techniques for modularity and re-use

Hi,

Please help if you can (with probably a very basic OO newbie question): -

I have created a class that uses the java.net.Socket class to talk to my
server and everything is great. I then converted the code to use the
javax.net.SSLSocket class and (thanks to how easy Java makes it for us!)
everything is still great. What I want to do now is parameterize/optionalize
the use of SSL or in-the-clear Sockets within my class, and I'm struggling
to find a modular, let alone elegant, solution.

At the moment I plan to add another Applet parameter called SSL_REQD and I
will pass that to my constructor, but because of Java's compile-time
resolution of methods-to-objects, I find myself having to duplicate code
that is erstwhile 99% identical or common. Is there some way (short of
Reflection) that I can leverage the fact SSLSocket class inherits most of
its methods from the Socket class so that I only need one method for each
socket function regardless of what flavour socket is in use?

For example: -

private someSocket t3Sock;

if (sssReqd)
  t3Sock = (SSLSocket)sockFactory.createSocket();
else
  t3Sock = new Socket();

t3Sock.setKeepAlive(true);

Am I stuck with "One's an Apple and the other's an Orange (albeit painted
red :-)"?

If few of the Socket methods are overridden by SSLSocket (and the
value-added encryption stuff happens at a lower/other level) can I just cast
my way around some of this? Just stick in a few "if" statements and stop
moanin'?

Cheers Richard Maher

Here is the complete Tier3Socket class definition: -

import java.io.BufferedOutputStream;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.UnknownHostException;
import java.net.SocketTimeoutException;
import java.lang.System;
import javax.net.ssl.SSLSocket;
import javax.net.ssl.SSLSocketFactory;

public class Tier3Socket
 {
 public static final
         String T3ID="T3$";
 public static final
         int USERSIZ=40;
 public static final
         int T3IDBUFSIZ=48;
 public static final
         int CREDBUFSIZ=80;
 public static final
         int CONTIMOUT=10000;

 public byte [] t3IdBuf;
 public byte [] readBuf;
 public byte [] writeBuf;

 private String host;
 private int port;
 private int maxBufSiz;
 private int bytesIn;
 private String hostCharSet;
 private SSLSocket t3Sock;
 private SSLSocketFactory sockFactory;
 private BufferedInputStream in;
 private BufferedOutputStream out;
 private byte [] outUser;
 private byte [] outPwd;
 private byte [] credBuf;
 private String inMsg;
 private String stringOut;

 Tier3Socket (String host, int port, int maxBufSiz, String hostCharSet)
 {
  this.host = host;
  this.port = port;
  this.maxBufSiz = maxBufSiz;
  this.hostCharSet = hostCharSet;
  this.bytesIn = 0;

  t3IdBuf = new byte[T3IDBUFSIZ];
  readBuf = new byte[maxBufSiz];

  sockFactory = (SSLSocketFactory)SSLSocketFactory.getDefault();
 }

 public void open() throws UnknownHostException, IOException
 {
  t3Sock = (SSLSocket)sockFactory.createSocket();
  t3Sock.setKeepAlive(true);
  t3Sock.setReuseAddress(true);
  t3Sock.setTcpNoDelay(true);

  t3Sock.connect(new InetSocketAddress(host,port), CONTIMOUT);

  System.out.println("Connected OK");

  in = new BufferedInputStream (t3Sock.getInputStream() ,maxBufSiz);
  out = new BufferedOutputStream (t3Sock.getOutputStream(),maxBufSiz);

  t3Sock.setUseClientMode(true);

  System.out.println("Going for SSL");

  try {t3Sock.startHandshake();}
      catch (IOException e)
            {
             System.out.println("Failed SSL Handshake");
             throw new IOException("Can't SSL on Socket");
            }
 }

 public void handShake(String username, String password) throws IOException
 {
  credBuf = new byte[CREDBUFSIZ];

  outUser = username.getBytes(hostCharSet);
  System.arraycopy(outUser, 0, credBuf, 0, outUser.length);

  outPwd = password.getBytes(hostCharSet);
  System.arraycopy(outPwd, 0, credBuf, USERSIZ, outPwd.length);

  out.write(credBuf, 0, CREDBUFSIZ);
  out.flush();

  if (in.read(t3IdBuf) < t3IdBuf.length)
  {
      System.out.println("Read < " + Integer.toString(t3IdBuf.length) + "
bytes");
      throw new IOException();
  }

  inMsg = new String(t3IdBuf, 0, 3, hostCharSet);

  if (!inMsg.equals(T3ID))
  {
      throw new IOException();
  }
 }

 public void sendUrgentData (int oob) throws IOException
 {
     t3Sock.sendUrgentData(oob);
 }

 public void setTimeout(int msecs) throws UnknownHostException, IOException
 {
  t3Sock.setSoTimeout(msecs);
 }

 public void close () throws IOException
 {
  if (t3Sock != null && !t3Sock.isClosed())
  {
      try {t3Sock.close();}
      catch (Exception e)
            {e.printStackTrace();}
  }
 }

 public void buffMessage (String message) throws IOException
 {
  byte [] msg = message.getBytes(hostCharSet);

  out.write(msg);
 }

 public void sendMessage (String message) throws IOException
 {
  byte [] msg = message.getBytes(hostCharSet);

  out.write(msg);
  flush();
 }

 public void flush () throws IOException
 {
  out.flush();
 }

 public int readMessage () throws IOException
 {
  return readMessage(readBuf.length);
 }

 public int readMessage (int bytes) throws IOException
 {
  try
      {
      bytesIn = in.read(readBuf, 0, bytes);
      }
  catch (SocketTimeoutException e)
      {
      return 0;
      }

  return bytesIn;
 }

 public String getString () throws ArrayIndexOutOfBoundsException
 {
  return getString(0, bytesIn);
 }

 public String getString (int offset, int length) throws
ArrayIndexOutOfBoundsException
 {
  if ((offset + length) > bytesIn)
  {
      throw new ArrayIndexOutOfBoundsException();
  }
  try
      {
      stringOut = new String(readBuf, offset, length, hostCharSet);
      }
  catch (Exception e)
      {
      return null;
      }

  return stringOut;
 }

}