Re: Applet "codebase" to IP address resolution

Hi Arne,

Thanks once more for your replies over the many months/years!


I doubt that's the definitive work on the subject :-)


Yeah, but what about the incoming UDP message-source check that must be
comparing IP addresses? When is the applet codebase address resolution
performed? (Please see the Tier3Pager and Tier3Talk classes below) And what
about that DNS cluster/interface load balancing?

Someone must have the source somewhere? Called a "Policy Manager/enforcer"
or some such? I'm guessing that consistency in this grey-area of "rules"
(more like guidelines realy :-) may be worthwhile across JVM
implementations?

Cheers Richard Maher

/**
  * Copyright Tier3 Software. All rights reserved.
  *
  * Author: Richard Maher
  *
 **/

import java.applet.Applet;
import java.awt.*;
import java.net.*;
import java.io.IOException;
import netscape.javascript.JSObject;
import netscape.javascript.JSException;

public class Tier3Pager extends Applet
{
    private String hostName;
    private JSObject browser;
    private static MessageThread socketThread;
    private static Tier3Talk chat;

    public class MessageThread extends Thread
    {
        private DatagramSocket socket;
        private DatagramPacket packet;
        private String threadData;

        public MessageThread(String name, String txt) throws Exception
        {
            super(name);

            byte[] buffer;
            threadData = txt;

            String port = getParameter("PORT");
            String maxBuf = getParameter("MAXBUF");
            try
                {
                if (port == null)
                    socket = new DatagramSocket();
                else
                    socket = new DatagramSocket(Integer.parseInt(port));

                if (maxBuf == null)
                    buffer = new byte[512];
                else
                    buffer = new byte[Integer.parseInt(maxBuf)];

                packet = new DatagramPacket(buffer, buffer.length);
                }
            catch (Exception e)
                {
                e.printStackTrace();
                System.out.println("Unable to create UDP Socket");
                throw new Exception("Message thread could not be created");
                }

            setDaemon(true);
            start();
        }

        public void shutdown()
        {
            socket.close();
        }

        public int getLocalPort()
        {
            return socket.getLocalPort();
        }

        public InetAddress getLocalAddress()
        {
         return socket.getLocalAddress();
        }

        public void run()
        {
            System.out.println("Started Message thread. ThreadData = " +
threadData);
            String args[] = {"Started Message Thread " + threadData};
            browser.call("alert", args);
            boolean stopThread = false;

        readLoop:
            while (!stopThread)
            {
              try
                  {
                  socket.receive(packet);
                  String received = new String(packet.getData(), 0,
packet.getLength());
                  processMessage(received);
                  }
              catch (SocketException e)
                  {
                  System.out.println("Shutting up shop");
                  stopThread = true;
                  continue readLoop;
                  }
              catch (IOException e)
                  {
                  e.printStackTrace();
                  System.out.println("Unable to retrieve UDP message");
                  }
            }

            System.out.println("Thread run() unit terminating");
        }

        public void processMessage(String msgText)
        {
             int msgType = Integer.parseInt(msgText.substring(0,2));
             switch (msgType){
               case 1:
                             chat.append(msgText.substring(2));
                             break;
               case 2:
                             String args[] = {msgText.substring(2)};
                             try {browser.call("priceUpdate", args);}
                             catch (JSException e)
                             {
                               System.out.println("Error when calling JS
priceUpdate()");
                             }
                             break;
               default:
                             System.out.println("Unknown rec type
"+msgText);
             }
        }
    }

    public void init()
    {
        System.out.println("Initializing. . .");
        hostName = getCodeBase().getHost();

        chat = new Tier3Talk("Tier3 Messages");
        requestFocus();

        browser = JSObject.getWindow(this);

        if (socketThread == null)
        {
          try
              {
              socketThread = new MessageThread("MsgDaemon", "SomeData");
              }
          catch (Exception e)
              {
              e.printStackTrace();
              System.out.println("Could not init Tier3Pager");
              }
        }
    }

    public void alert(String alertText)
    {
        String args[] = {alertText};
        browser.call("alert", args);
    }

    public void destroy()
    {
        if (chat != null)
            chat.dispose();

        boolean stillDying;

        if (socketThread != null){
            socketThread.shutdown();
            do
            {
                stillDying = false;
                System.out.println("Joining MessageThread");
                try {socketThread.join();}
                catch (InterruptedException e){
                    System.out.println("Interrupted Join");
                    stillDying = true;
                }
            } while (stillDying);

            socketThread = null;
        }

        System.out.println("Tier3Pager Applet Rundown complete");
        super.destroy();
    }
}

/**
  * Copyright Tier3 Software. All rights reserved.
  *
  * Author: Richard Maher
  *
 **/

import java.awt.*;
import java.awt.event.*;

public class Tier3Talk extends Frame
                        implements WindowStateListener
{
    TextArea chatPanel = new TextArea("Server messages will appear
below: -", 10, 50);
    Toolkit toolkit = Toolkit.getDefaultToolkit();
    boolean windowDown = true;

    public Tier3Talk(String heading)
    {
        super(heading);
        setBackground(Color.gray);

        chatPanel.setEditable(false);

        Panel panel = new Panel();
        panel.setLayout(new FlowLayout(FlowLayout.CENTER));
        panel.add(chatPanel);
        add("Center", panel);

        Dimension screenDim = toolkit.getScreenSize();
        pack();
        Dimension windowDim = getSize();
        setLocation((screenDim.width - windowDim.width),(screenDim.height -
windowDim.height));

        setResizable(false);
        addWindowStateListener(this);
        setExtendedState(Frame.ICONIFIED);
        setVisible(true);
    }

    public void append(String newMsg)
    {
        chatPanel.append("\n" + newMsg);
        if (windowDown)
            setExtendedState(Frame.NORMAL);
        toolkit.beep();
    }

    public void windowStateChanged(WindowEvent we)
    {
        switch (we.getNewState())
        {
            case Frame.ICONIFIED:
                windowDown = true;
                break;
            case Frame.NORMAL:
                windowDown = false;
                break;
            default:
                System.out.println("Event of no interest" +
we.getNewState());
        }
    }
}

"Arne Vajh?j" <arne@vajhoej.dk> wrote in message
news:489664d0$0$90271$14726298@news.sunsite.dk...


same IP


URL


when


addresses


nice