# Security violation

Kristian Wendel (kribb@keyway.net)
Fri, 13 Feb 1998 17:46:43 -0800

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    From: "Kristian Wendel" <kribb@keyway.net>

    To: <java-security@web2.javasoft.com>

    Subject: Security violation

    Date: Fri, 13 Feb 1998 17:46:43 -0800

This is a multi-part message in MIME format.

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Hello!

I have written a Java animation applet. It works just fine on my =
computer, but when my friends try to view the webpage, the applet will =
not load, in the statusbar comes the message - security violation, what =
does this mean, and what can be done about it?

The applet doesn't perform anything strange or evil, just a basic =
animation, with the possibilites for the user to start and stop it, as =
well as changing the framerate.

I have provided you with the code

Hoping for an answer

Sincerely

Kristian Wendel

import java.awt.*;

import java.awt.event.*;

import java.applet.Applet;

public class KW extends Applet implements Runnable, ItemListener

{=20

static int i, framerate =3D 100;

Thread animatorThread =3D null;

boolean frozen =3D false;

Image[] images;

Graphics offGraphics;

Image offImage;

Panel sp =3D new Panel();

CheckboxGroup framerategroup =3D new CheckboxGroup();

Checkbox[] selectedframerate =3D new Checkbox[3];

MediaTracker tracker;

public void init()

{

setLayout(new BorderLayout(5,5));

add("South", sp);

sp.add(selectedframerate[0] =3D new Checkbox("1",framerategroup,true));

sp.add(selectedframerate[1] =3D new Checkbox("2",framerategroup,false));

sp.add(selectedframerate[2] =3D new Checkbox("3",framerategroup,false));

selectedframerate[0].addItemListener(this);

selectedframerate[1].addItemListener(this);

selectedframerate[2].addItemListener(this);

tracker =3D new MediaTracker(this);

images =3D new Image[38];

for (i =3D 1; i <=3D 38; i++)

{

images[i-1] =3D getImage(getCodeBase(), "kw"+i+".jpg");

tracker.addImage(images[i-1], 0);

}

addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

if (frozen)

{

frozen =3D false;

start();

}=20

else

{

frozen =3D true;

animatorThread =3D null;

}

}

});

}

public void start()

{

if (frozen) {}=20

else

{

if (animatorThread =3D=3D null)

{

animatorThread =3D new Thread(this);

}

animatorThread.start();

}

}

public void stop()

{

animatorThread =3D null;

}

public void run()

{

try

{

tracker.waitForAll();

} catch (InterruptedException e) {}

long startTime =3D System.currentTimeMillis();=20

Thread currentThread =3D Thread.currentThread();=20

while (currentThread =3D=3D animatorThread)

{

for (i =3D 0; i <=3D 38; i++)

{

repaint();

try

{

startTime +=3D framerate;

Thread.sleep(Math.max(0,=20

startTime-System.currentTimeMillis()));

}

catch (InterruptedException e)

{

break;

}

}

}

}

public void paint(Graphics g)

{

update(g);

}

public final void update(Graphics g)

{

if (!tracker.checkAll())

{

g.clearRect(0,0,160,120);

g.drawString("This may take a while,", 25, 55);

g.drawString("about 15 - 60 seconds", 25, 70);

g.drawString(" Have patience ", 25, 85);

}

offImage =3D createImage(160,120);

offGraphics =3D offImage.getGraphics();=20

offGraphics.setColor(getBackground());

offGraphics.fillRect(0,0,160,120);

offGraphics.setColor(Color.black);

offGraphics.drawImage(images[i-1],0,0,this);

g.drawImage(offImage, 0, 0, this);

}

public void itemStateChanged(ItemEvent e)

{

if (framerategroup.getSelectedCheckbox()=3D=3Dselectedframerate[0])

framerate =3D 100;

else if (framerategroup.getSelectedCheckbox()=3D=3Dselectedframerate[1])

framerate =3D 150;

else if (framerategroup.getSelectedCheckbox()=3D=3Dselectedframerate[2])

framerate =3D 300;

}

}

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<!DOCTYPE HTML PUBLIC "-//W3C//DTD W3 HTML//EN">

Hello!

I have written a Java animation applet. It works just fine on my = computer,=20 but when my friends try to view the webpage, the applet will not load, = in the=20 statusbar comes the message - security violation, what does this mean, = and what=20 can be done about it?

The applet doesn't perform anything strange or evil, just a basic = animation,=20 with the possibilites for the user to start and stop it, as well as = changing the=20 framerate.

I have provided you with the code

Hoping for an answer

Sincerely

Kristian Wendel

import java.awt.*;

import java.awt.event.*;

import java.applet.Applet;

public class KW extends Applet implements Runnable, ItemListener

{

static int i, framerate =3D 100;

Thread animatorThread =3D null;

boolean frozen =3D false;

Image[] images;

Graphics offGraphics;

Image offImage;

Panel sp =3D new Panel();

CheckboxGroup framerategroup =3D new CheckboxGroup();

Checkbox[] selectedframerate =3D new Checkbox[3];

MediaTracker tracker;

public void init()

{

setLayout(new BorderLayout(5,5));

add("South", sp);

sp.add(selectedframerate[0] =3D new=20 Checkbox("1",framerategroup,true));

sp.add(selectedframerate[1] =3D new=20 Checkbox("2",framerategroup,false));

sp.add(selectedframerate[2] =3D new=20 Checkbox("3",framerategroup,false));

selectedframerate[0].addItemListener(this);

selectedframerate[1].addItemListener(this);

selectedframerate[2].addItemListener(this);

tracker =3D new MediaTracker(this);

images =3D new Image[38];

for (i =3D 1; i <=3D 38; i++)

{

images[i-1] =3D getImage(getCodeBase(), = "kw"+i+".jpg");

tracker.addImage(images[i-1], 0);

}

addMouseListener(new MouseAdapter()

{

public void mousePressed(MouseEvent e)

{

if (frozen)

{

frozen =3D false;

start();

}

else

{

frozen =3D true;

animatorThread =3D null;

}

}

});

}

public void start()

{

if (frozen) {}

else

{

if (animatorThread =3D=3D null)

{

animatorThread =3D new Thread(this);

}

animatorThread.start();

}

}

public void stop()

{

animatorThread =3D null;

}

public void run()

{

try

{

tracker.waitForAll();

} catch (InterruptedException e) {}

long startTime =3D System.currentTimeMillis();

Thread currentThread =3D Thread.currentThread();

while (currentThread =3D=3D animatorThread)

{

for (i =3D 0; i <=3D 38; i++)

{

repaint();

try

{

startTime +=3D framerate;

Thread.sleep(Math.max(0,

startTime-System.currentTimeMillis()));

}

catch (InterruptedException e)

{

break;

}

}

}

}

public void paint(Graphics g)

{

update(g);

}

public final void update(Graphics g)

{

if (!tracker.checkAll())

{

g.clearRect(0,0,160,120);

g.drawString("This may take a while,", 25, 55);

g.drawString("about 15 - 60 seconds", 25, 70);

g.drawString(" Have patience ", 25, 85);

}

offImage =3D createImage(160,120);

offGraphics =3D offImage.getGraphics();

offGraphics.setColor(getBackground());

offGraphics.fillRect(0,0,160,120);

offGraphics.setColor(Color.black);

offGraphics.drawImage(images[i-1],0,0,this);

g.drawImage(offImage, 0, 0, this);

}

public void itemStateChanged(ItemEvent e)

{

if = (framerategroup.getSelectedCheckbox()=3D=3Dselectedframerate[0])

framerate =3D 100;

else if = (framerategroup.getSelectedCheckbox()=3D=3Dselectedframerate[1])

framerate =3D 150;

else if = (framerategroup.getSelectedCheckbox()=3D=3Dselectedframerate[2])

framerate =3D 300;

}

}

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