Hi,

I have modify a bit this code from "Cay Horstmann" but it does not find the
.caesar class and the catalog.txt from inside a jar file. I I jar everything
and add the two files 'outside' the jar it works fine.

I tried to fit getRessourceAsStream in it without success.
                                       Any clue appreciated,

                                                                   Jean

======================

import java.util.*;
import java.io.*;
import java.lang.reflect.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

class MyClassLoader extends JFrame
{
public static void main(String[] args)
  {
new MyClassLoader().runClass();
  }
  public void runClass()
  {  try
     {  ClassLoader loader
           = new CryptoClassLoader();
        Class c = loader.loadClass("MusicCatalog");
        String[] args = new String[] {};

        Method m = c.getMethod("main",
           new Class[] { args.getClass() });
        m.invoke(null, new Object[] { args });
     }
     catch (Throwable e)
     {  JOptionPane.showMessageDialog(this, e);
     }
  }
}

class CryptoClassLoader extends ClassLoader
{
  protected synchronized Class loadClass(String name,
     boolean resolve) throws ClassNotFoundException
  {  // check if class already loaded
     Class cl = (Class)classes.get(name);

     if (cl == null) // new class
     {  try
        {  // check if system class
           return findSystemClass(name);
        }
        catch (ClassNotFoundException e) {}
        catch (NoClassDefFoundError e) {}

        // load class bytes--details depend on class loader

        byte[] classBytes = loadClassBytes(name);
        if (classBytes == null)
           throw new ClassNotFoundException(name);

        cl = defineClass(name, classBytes,
           0, classBytes.length);
        if (cl == null)
           throw new ClassNotFoundException(name);

        classes.put(name, cl); // remember class
     }

     if (resolve) resolveClass(cl);

     return cl;
  }

  private byte[] loadClassBytes(String name)
  {  String cname = name.replace('.', '/') + ".caesar";
     FileInputStream in = null;
     try
     {  in = new FileInputStream(cname);
        ByteArrayOutputStream buffer
           = new ByteArrayOutputStream();
        int ch;
        while ((ch = in.read()) != -1)
        {  byte b = (byte)(ch - 3);
           buffer.write(b);
        }
        in.close();
        return buffer.toByteArray();
     }
     catch (IOException e)
     {  if (in != null)
        {  try { in.close(); } catch (IOException e2) { }
        }
        return null;
     }
  }

  private Map classes = new HashMap();
}