package com.bexp;

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

public class NetworkClassLoader
//    extends ClassLoader
    extends URLClassLoader
{
//    ClassLoader parent = null;
//    ClassLoader jar = null;
    
    //ClassLoader local_loader = null;
/*    
    public NetworkClassLoader() throws Exception
        {
        super();
        System.out.println("Default constructor");//testing
        }
*/
    ClassLoader fallback;
    
    public NetworkClassLoader(ClassLoader _parent) throws Exception
        {
        //super(_parent);
        
        super(new URL[]
             {(new URI("file:client.jar")).toURL()},_parent);
        fallback = new URLClassLoader(new URL[]{(new URI("file:client.jar")).toURL()},this);
        
        //super.loadClass("com.bexp.ejb.ObjSession",true);
        //System.out.println("constructor; parent: "+_parent);//testing
        /*
        jar = new java.net.URLClassLoader(new java.net.URL[]
                  {(new java.net.URI("file:client.jar")).toURL()},_parent);
        */
        }
    
    protected synchronized Class findClass(String name) throws ClassNotFoundException
        {
        //System.out.println("@@@@@@@@@@ finding class "+name);//testing
        //if(name.startsWith("[")) { System.out.println("@@@@@@@@@@ finding class "+name); }//testing
        try
        { return super.findClass(name); }
            catch(Throwable ex)
            {
            if(name.startsWith("com.bexp.swing")) { throw new ClassNotFoundException(); }
            //if((name.startsWith("[L"))&&(name.endsWith(";")))
            if((name.startsWith("[")))
                {
                //loadClass(name.substring(2, name.length()-1));
                return Class.forName(name, false, fallback);
                }
                //^^^- na nat i suda nat
            //System.out.println("-------- downloading class "+name);//testing
            //System.out.println("$$$$$$$$$$ "+ex);//testing
            //throw new ClassNotFoundException();
            return downloadClass(name);
            }
        }
    
        static String hostname="unspecified";
    public static String getHostName()
        { return hostname; }
    public static void setHostName(String _hostname)
        { hostname = _hostname; }
    
    Class downloadClass(String name) throws ClassNotFoundException
        {
        try
        {
        java.net.URLConnection connection
        = (new java.net.URI("http://"+hostname+
            ":8080/BEXP_SD/classSource?classname="+name))
            .toURL().openConnection();
       
        InputStream istream = new BufferedInputStream(connection.getInputStream());
        byte[] buf = new byte[istream.available()];
        ByteArrayOutputStream dstream = new ByteArrayOutputStream(istream.available());
        //istream.read(data);
        int bytesRead;
        while ((bytesRead = istream.read(buf)) != -1)
            { dstream.write(buf, 0, bytesRead); }
        byte[] data = dstream.toByteArray();
        istream.close();
        //System.out.println("Bytes read: "+data.length);//testing
        int realStart = 0;//9;
        //if(true){ System.out.println("******"+name); }//testing
        return defineClass(name,data,realStart,data.length-realStart);
        } catch(Exception ex)
            {
            ex.printStackTrace();//debug
            throw new ClassNotFoundException();
            }
        }
/*    
    public synchronized Class loadClass(String name) throws ClassNotFoundException
        {
        System.out.println("@@@@@@@@@@ load1 "+name);//testing
        try
        { return super.loadClass(name); }
        catch(Throwable ex)
            {
            /*
            try
            { return super.loadClass(name,true); }
            catch(Throwable exx)
                {
                //System.out.println("-------- downloading class "+name);//testing
                System.out.println("$$$$$$$$$$ "+exx);//testing
                throw new ClassNotFoundException();
                //return loadClass(name,true);
                }
            * /
            System.out.println("######### "+ex);//testing
            throw new ClassNotFoundException();
            }
        }
    
    protected synchronized Class loadClass(String name, boolean resolve) throws ClassNotFoundException
        {
        System.out.println("@@@@@@@@@@ load2 "+name);//testing
        Class result;
        try
        { result = super.loadClass(name,resolve); }
        catch(Throwable ex)
        {
            try {
                //System.out.println("ddd");//testing
                result = jar.loadClass(name);
                }
            catch(Throwable exx)
            {
            System.out.println("-------- downloading class "+name);
            /*
            try
            {
            
            }catch(Throwable exxx)
            {
            exxx.printStackTrace();//testing
            throw new ClassNotFoundException("Server unreachable");
            }
            * /
            throw new ClassNotFoundException();
            }
        //System.out.println("-------- downloading class "+name);//testing
        //System.out.println("$$$$$$$$$$ "+ex);//testing
        throw new ClassNotFoundException();
        }
        return result;
        }    
*/    
}