Applet not running

[Josh Diamond]

Trying to run this applet and am getting this error message: Exception in thread "pool-1-thread-1" java.security.AccessControlException: access denied ("java.lang.RuntimePermission" "modifyThreadGroup")

I'm created the html file for the applet and in addition added the comment //<applet code = "NotPong.class" width = 400 height = 200> </applet> at the top of the applet. I've also tried to edit the java.policy file with the policy tool by adding  permission java.lang.RuntimePermission "modifyThreadGroup";

There shouldn't be anything wrong with the applet itself because it's from a book but I have no idea why it is not running. Any ideas?

//<applet code = "NotPong.class" width = 400 height = 200> </applet>
import java.applet.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.geom.*;
import java.util.concurrent.*;

public class NotPong extends JApplet	
{
    public static final int WIDTH = 400;
    public static final int HEIGHT = 400;

    private PaintSurface canvas;

    public void init()	
    {
        this.setSize(WIDTH, HEIGHT);
        canvas = new PaintSurface();
        this.add(canvas, BorderLayout.CENTER);
        ScheduledThreadPoolExecutor executor = 
            new ScheduledThreadPoolExecutor(3);
        executor.scheduleAtFixedRate(new AnimationThread(this), 
            0L, 20L, TimeUnit.MILLISECONDS); 
    }
}

class AnimationThread implements Runnable	
{
    JApplet c;

        public AnimationThread(JApplet c)
    {
        this.c = c;
    }

        public void run()
    {
        c.repaint();
    }
}

class PaintSurface extends JComponent	
{
    int paddle_x = 0;	
    int paddle_y = 360;

    int score = 0;	
    float english = 1.0f;

    Ball ball;	

    Color[] color = {Color.RED, Color.ORANGE, 	
                     Color.MAGENTA, Color.ORANGE, 
                     Color.CYAN, Color.BLUE};
    int colorIndex;

    public PaintSurface()	
    {
        addMouseMotionListener(new MouseMotionAdapter()
            {
                public void mouseMoved(MouseEvent e)
                {
                    if (e.getX() - 30 - paddle_x > 5)
                        english = 1.5f;
                    else if (e.getX() - 30 - paddle_x < -5)
                        english = -1.5f;
                    else
                        english = 1.0f;
                    paddle_x = e.getX() - 30;
                }
            } );
        ball = new Ball(20);
    }

    public void paint(Graphics g)	
    {
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(
            RenderingHints.KEY_ANTIALIASING,
            RenderingHints.VALUE_ANTIALIAS_ON);
        Shape paddle = new Rectangle2D.Float(	
            paddle_x, paddle_y, 60, 8);

        g2.setColor(color[colorIndex % 6]);	

        if (ball.intersects(paddle_x, paddle_y, 60, 8)	
            && ball.y_speed > 0)
        {
            ball.y_speed = -ball.y_speed;
            ball.x_speed = (int)(ball.x_speed * english);
            if (english != 1.0f)
                colorIndex++;
            score += Math.abs(ball.x_speed * 10);
        }

        if (ball.getY() + ball.getHeight()	
            >= NotPong.HEIGHT)
        {
            ball = new Ball(20);
            score -= 1000;
            colorIndex = 0;
        }
        ball.move();	
        g2.fill(ball);

        g2.setColor(Color.BLACK);	
        g2.fill(paddle);
        g2.drawString("Score: " + score, 250, 20);	

    }
}

class Ball extends Ellipse2D.Float	
{
    public int x_speed, y_speed;
    private int d;
    private int width = NotPong.WIDTH;
    private int height = NotPong.HEIGHT;

    public Ball(int diameter)
    {
        super((int)(Math.random() * (NotPong.WIDTH - 20) + 1),
              0, diameter, diameter);
        this.d = diameter;
        this.x_speed = (int)(Math.random() * 5 + 5);
        this.y_speed = (int)(Math.random() * 5 + 5);
    }

    public void move()
    {
        if (super.x < 0 || super.x > width - d)
            x_speed = -x_speed;
        if (super.y < 0 || super.y > height - d)
            y_speed = -y_speed;
        super.x += x_speed;
        super.y += y_speed;
    }
}

[Norm Radder]

What program are you using to execute the applet?
It works for me in AppletViewer.

[Stephan van Hulst]

Applets are a mostly deprecated technology. Is there a good reason to keep using them? Most browsers drastically limit what an applet is allowed to do.

[Josh Diamond]

Norm Radder wrote:What program are you using to execute the applet?
It works for me in AppletViewer.

Using appletviewer.

[Norm Radder]

What's in your .java.policy file?

Mine has these lines near the front:

grant {
  permission java.lang.RuntimePermission "modifyThread";
  permission java.lang.RuntimePermission "loadLibrary.HelloNative";
  permission java.util.PropertyPermission "*", "read";
  permission java.lang.RuntimePermission "modifyThreadGroup";

Aother possibility: use a private policy file:

mypolicy.policy:

/* AUTOMATICALLY GENERATED ON Tue Aug 10 13:23:54 CDT 2010*/
/* DO NOT EDIT */

grant {
  permission java.lang.RuntimePermission "modifyThread";
  permission java.lang.RuntimePermission "modifyThreadGroup";
};

Command line:

"C:\Program Files\Java\jdk1.8.0_60\bin\appletviewer.exe" -J-Djava.security.policy=mypolicy.policy NotPong.java