J'essaie d'exécuter ces applets pour mon cours de réseautage. Quand j'ai essayé de les exécuter dans le navigateur à partir des liens, ils n'ont rien fait. J'ai donc décidé d'essayer de les compiler dans IntelliJ mais quand j'ai exécuté le code, il n'a rien fait. Aucun message d'erreur retourné. La seule chose que j'ai faite pour changer le code du code source a été d'ajouter la méthode principale et de supprimer la déclaration de package. Ce qui suit est l'applet que j'essayais d'exécuter:

Code JAVA

///////////////////////////////////////
//LineSimApllet
//written by David Grangier, Institut Eurecom, France
//[email protected]
///////////////////////////////////////
//imports

import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import java.applet.*;
import java.util.*;

//Applet Class
public class LineSimApplet extends Applet {
    //buttons
    Button start = new Button("Start");
    Button stop = new Button("Reset");
    //features lists
    MyChoice length = new MyChoice(new String[]{"10 km", "100 km", "1000 km"}, new double[]{10E3, 100E3, 1E6}, 3);
    MyChoice rate = new MyChoice(new String[]{"512 kps", "1 Mbps", "10 Mbps", "100 Mbps"}, new double[]{512E3, 1E6, 10E6, 100E6}, 2);
    MyChoice size = new MyChoice(new String[]{"100 Bytes", "500 Bytes", "1 kBytes"}, new double[]{8E2, 4E3, 8E3}, 1);
    //to simulate time
    Thread timerThread;
    TickTask timerTask;
    boolean simulationRunning = false;
    //communication line
    Line myLine;

    public void init() {
        try {
            setBackground(Color.white);
            add(new Label("Length", Label.RIGHT));
            add(length);
            add(new Label("Rate", Label.RIGHT));
            add(rate);
            add(new Label("Packet size", Label.RIGHT));
            add(size);
            //start
            start.addActionListener(
                    new ActionListener() {
                        public void actionPerformed(ActionEvent event) {
                            launchSim();
                        }
                    });
            add(start);
            //stop
            Button stop = new Button("Reset");
            stop.addActionListener(
                    new ActionListener() {
                        public void actionPerformed(ActionEvent event) {
                            stopSim();
                            //clear line
                            myLine.sendTime(0);
                            //redraw cleared line
                            LineSimApplet.this.repaint();
                        }
                    });
            add(stop);
            //line
            myLine = new Line(40, 50, 450, 10);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void paint(Graphics g) {
        update(g); // eliminate flashing : update is overriden
    }

    public void update(Graphics g) { //work on a offscreen image

        Dimension offDimension = getSize();
        Image offImage = createImage(offDimension.width, offDimension.height);
        Graphics offGraphics = offImage.getGraphics();
        myLine.drawLine(offGraphics);

        //sender
        offGraphics.setColor(Color.blue);
        offGraphics.fillRect(10, 40, 30, 30);
        offGraphics.setColor(Color.black);
        offGraphics.drawString("Sender", 5, 90);
        offGraphics.drawRect(10, 40, 30, 30);

        //receiver
        offGraphics.setColor(Color.blue);
        offGraphics.fillRect(490, 40, 30, 30);
        offGraphics.setColor(Color.black);
        offGraphics.drawString("Receiver", 485, 90);
        offGraphics.drawRect(490, 40, 30, 30);

        offGraphics.drawString("Propagation speed : 2.8 x 10^8 m/sec", 175, 105);
        //display offscreen image
        g.drawImage(offImage, 0, 0, this);
    }

    private void launchSim() {
        setupEnabled(false);
        //setup line
        myLine.setup(length.getVal(), rate.getVal());
        myLine.emitPacket(size.getVal(), 0);
        //setup timer
        timerTask = new TickTask(1E-5, myLine.totalTime());
        timerThread = new Thread(timerTask);
        //start simulation
        simulationRunning = true;
        timerThread.start();
    }

    private void stopSim() {
        timerTask.endNow();
        simulationRunning = false;
        setupEnabled(true);
    }

    public void setupEnabled(boolean value) {
        start.setEnabled(value);
        length.setEnabled(value);
        rate.setEnabled(value);
        size.setEnabled(value);
    }

    //my choice
    class MyChoice extends Choice {
        private double vals[];

        public MyChoice(String items[], double values[], int defaultValue) {
            for (int i = 0; i < items.length; i++) {
                super.addItem(items[i]);
            }
            vals = values;
            select(defaultValue - 1);
        }

        public double getVal() {
            return vals[super.getSelectedIndex()];
        }
    }

    //tickTask
    class TickTask implements Runnable {
        private double counter;
        private double length;
        private double tick;

        public TickTask(double t, double l) {
            length = l;
            tick = t;
            counter = 0;
        }

        public void run() {
            while (LineSimApplet.this.simulationRunning) {
                counter += tick;
                LineSimApplet.this.myLine.sendTime(counter);
                LineSimApplet.this.repaint();
                if (counter >= length) {
                    LineSimApplet.this.myLine.clearPackets();
                    LineSimApplet.this.timerThread.suspend();
                }
                try {
                    LineSimApplet.this.timerThread.sleep(50);
                } catch (Exception e) {
                }
            }
        }

        public void endNow() {
            length = counter;
        }
    }
}

//Line class
class Line {
    //graphic variables
    private int gX;
    private int gY;
    private int gWidth;
    private int gHeight;
    //characteristic variables
    final double celerity = 2.8E+8;
    private double length;
    private double rate;
    //simulation variables
    private double time;
    private Packet myPacket;

    public Line(int x, int y, int w, int h) {
        //graphic init
        gX = x;
        gY = y;
        gWidth = w;
        gHeight = h;
    }

    public void setup(double l, double r) {
        length = l;
        rate = r;
    }

    void sendTime(double now) {
        time = now; //update time
        removeReceivedPackets(now);
    }

    void emitPacket(double s, double eT) {
        myPacket = new Packet(s, eT);
    }

    private void removeReceivedPackets(double now) {
        if (!(myPacket == null)) {
            if (now > myPacket.emissionTime + (myPacket.size / rate) + length * celerity) {
                clearPackets();
            }
        }
    }

    public void clearPackets() {
        myPacket = null;
    }

    public double totalTime() {
        double emmissionTime = (myPacket.size / rate);
        double onLineTime = (length / celerity);
        return (emmissionTime + onLineTime);
    }

    public void drawLine(Graphics g) {
        g.setColor(Color.white);
        g.fillRect(gX, gY + 1, gWidth, gHeight - 2);
        g.setColor(Color.black);
        g.drawRect(gX, gY, gWidth, gHeight);
        g.setColor(Color.red);
        g.drawString(timeToString(time), gX + gWidth / 2 - 10, gY + gHeight + 15);
        drawPackets(g);
    }

    private void drawPackets(Graphics g) {
        if (!(myPacket == null)) {
            double xfirst;
            double xlast;
            //compute time units
            xfirst = time - myPacket.emissionTime;
            xlast = xfirst - (myPacket.size / rate);
            //compute position
            xfirst = xfirst * celerity * gWidth / length;
            xlast = xlast * celerity * gWidth / length;
            if (xlast < 0) {
                xlast = 0;
            }
            if (xfirst > gWidth) {
                xfirst = gWidth;
            }
            //draw
            g.setColor(Color.red);
            g.fillRect(gX + (int) (xlast), gY + 1, (int) (xfirst - xlast), gHeight - 2);
        }
    }

    static private String timeToString(double now) {
        String res = Double.toString(now * 1000);
        int dot = res.indexOf('.');
        String deci = res.substring(dot + 1) + "000";
        deci = deci.substring(0, 3);
        String inte = res.substring(0, dot);
        return inte + "." + deci + " ms";
    }

    public static void main(String[] args) {
        LineSimApplet ls = new LineSimApplet();
        ls.init();
    }
}

class Packet {
    double size;
    double emissionTime;

    Packet(double s, double eT) {
        size = s;
        emissionTime = eT;
    }
}

Comment peut-on J'exécute cette applet en utilisant IntelliJ?