import java.util.Hashtable;
import java.net.*;
import java.io.*;

public class URLClassLoader extends ClassLoader {

Hashtable cache;
URL u;

    public URLClassLoader(URL u) {
      this.u=u;
      cache = new Hashtable();
    }

public synchronized Class loadClass(String name, boolean reslove)
    throws ClassNotFoundException {


Class c = (Class) cache.get(name);
 if(c==null) {
     try {
        c =findSystemClass(name);
     }
     catch (ClassNotFoundException e) {}
 }

 if(c==null) {
     byte b[] = loadClassData(name);
     c = defineClass(b,0,b.length);
     cache.put(name,c);
 }

 System.out.println("now resolve"); 
 if(reslove) {
     System.out.println("resolve class "+c.getName());
     resolveClass(c);
 }
 System.out.println("done"); 

  return c;

}

  private getPackageContents(String packageName){
   String baseURL
  } 


private byte[] loadClassData(String name)
    throws ClassNotFoundException {

byte[] b;
InputStream theClass = null;
int bfr =128;

 try {
 URL classURL = new URL(u, name+".class");

 URLConnection uc = classURL.openConnection();
 uc.setAllowUserInteraction(false);
 try {
  theClass = uc.getInputStream();
 }
 catch (NullPointerException e) {
   System.out.println(e);
   throw new ClassNotFoundException(name+" input stream problem");
 }
 int cl = uc.getContentLength();
 if(cl==-1) { b = new byte[bfr*30];}
 else { b = new byte[cl+bfr];}
   System.out.println("0");

int  bytesread =0;
int offset =0;

while (bytesread >= 0) {
   bytesread = theClass.read(b,offset,bfr);
   if(bytesread == -1) break;
   offset += bytesread;
   System.out.println(offset+" of "+b.length+" of "+cl);
   if(cl ==-1 && offset == b.length){
       byte temp[] = new byte[offset*2];
       System.arraycopy(b,0,temp,0,offset);
       b=temp;
   }
   else if(offset > b.length) {
    throw new ClassNotFoundException(name + " error reading data into array");
   }
}

   System.out.println("2");

if(offset < b.length) {
   System.out.println("arraycopy");
   byte temp[] = new byte[offset];
   System.arraycopy(b,0,temp,0,offset);
   b=temp;
}

if(cl != -1 && offset != cl) {
   throw new ClassNotFoundException("Only "+offset+" bytes received for "
              +name +"\n Expected "+cl+" bytes");
 }
System.out.println("done?");

}
catch (Exception e) {
   throw new ClassNotFoundException(name + " "+e);
}

finally {
  try {
    if(theClass != null) theClass.close();
  }
  catch (Exception e) {}
}

System.out.println("return");
return b;
}

}