import java.io.*;
import java.util.*;
import javax.mail.internet.*;
import javax.mail.*;

    public class mail {
  public static void main(String args[])throws Exception
     {
    
    Properties p = new Properties();
    p.put("mail.host" , "mail.pl");
    Session s = Session.getInstance(p,null);
    Message m = new MimeMessage(s);
    m.setFrom(new InternetAddress("moj_adres@cos.pl"));
    m.setRecipient(Message.RecipientType.TO, new InternetAddress("odbiorca@mail.pl"));
    m.setSubject("...");
    m.setContent("To jest list" , "text/plain");
    
    Transport.send(m);
    };
    };

import java.awt.*;
import javax.swing.*;
import java.awt.event.*;

public
  class Kulki
  extends JPanel
  implements ActionListener {

  public static void main(String[] args) {
    JFrame frame = new JFrame("Kulki");
    Container cp = frame.getContentPane();
    Kulki kulki = new Kulki();
    cp.add(kulki);
    frame.addKeyListener(kulki.bar);
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    frame.setResizable(false);
    frame.setLocation(300, 300);
    frame.pack();
    frame.show();
    kulki.startGame();
  }

  public static final Dimension SIZE = new Dimension(300, 300); // Pulpit
  public static final int REFRESH = 40; // Odświeżanie pulpitu co REFRESH ms.
  private Bar bar = new Bar();
  private Ball[] balls = {
    new Ball(Color.magenta, bar),
    new Ball(Color.green, bar),
    new Ball(Color.blue, bar),
    new Ball(Color.red, bar),
  };
  private Image image;
  private Graphics graph;

  public Kulki() {
    setPreferredSize(Kulki.SIZE);
  }

  public void startGame() {
    image = createImage(SIZE.width, SIZE.height);
    graph = image.getGraphics();
    for (int i = 0; i < balls.length; i++)
      balls[i].start();
    Timer timer = new Timer(REFRESH, this);
    timer.start();
  }

  public void paintComponent(Graphics g) {
    super.paintComponent(g);
    if (image != null)
      g.drawImage(image, 0, 0, this);
  }

  public void actionPerformed(ActionEvent evt) {
    graph.setColor(Color.cyan);
    graph.fillRect(0, 0, SIZE.width, SIZE.height);
    bar.draw(graph);
    for (int i = 0; i < balls.length; i++)
      balls[i].draw(graph);
    repaint();
  }

}

class Bar
  extends KeyAdapter {

  public static final int BAR_VEL = 20; // Szybkość przesuwania klocka.
  public static final Dimension SIZE = new Dimension(80, 10);
  private int pos;

  public Bar(){
    pos = (Kulki.SIZE.width - SIZE.width) / 2;
  }

  public void draw(Graphics g){
    g.setColor(Color.white);
    // zbędna synchronizacja
    g.fill3DRect(pos, Kulki.SIZE.height - SIZE.height - 1,
                   SIZE.width, SIZE.height, true);
  }

  public void keyPressed(KeyEvent evt) {
    switch (evt.getKeyCode()) {
      case KeyEvent.VK_LEFT:
        synchronized(this){
          if (pos > 0)
            pos -= BAR_VEL;
        }
        break;
      case KeyEvent.VK_RIGHT:
        synchronized(this){
          if (pos + SIZE.width < Kulki.SIZE.width)
            pos += BAR_VEL;
        }
        break;
      case KeyEvent.VK_ESCAPE:
        System.exit(0);
    }
  }

  public synchronized boolean bump(Point p){
    return p.y + Ball.SIZE > Kulki.SIZE.height - SIZE.height &&
           p.x + Ball.SIZE / 2 < pos + SIZE.width &&
           p.x + Ball.SIZE / 2 > pos;
  }
}

class Ball
  implements Runnable {

  public static final int SPEED = Kulki.REFRESH;  // Częstośc obliczania pozycji
  public static final int SIZE = 25;  // Średnica kulki.
  // Graniczne prędkości kulek (względne).
  public static final int MAX_VEL = 4;
  public static final int MIN_VEL = 2;

  private int dx;
  private int dy;
  private Point pos;
  private Color color;
  private boolean running = true;
  private Bar bar;

  public Ball(Color c, Bar b) {
    color = c;
    bar   = b;
    double x = (Kulki.SIZE.width - SIZE) * Math.random();
    double y = (Kulki.SIZE.height - Bar.SIZE.height - SIZE) * Math.random();
    pos = new Point( (int) x, (int) y);
    int d = MAX_VEL - MIN_VEL;
    dy = ( -1) * (int) (d * Math.random() + MIN_VEL);
    dx = (int) (2 * MAX_VEL * Math.random() - MAX_VEL);
  }

  public void start(){
    new Thread(this).start();
  }

  public void run() {
    while(running){
      try {
        Thread.sleep(SPEED);
      }
      catch(InterruptedException e){
      }
      synchronized (pos) {
        pos.translate(dx, dy);
      }
      if (pos.x < 0 || pos.x > Kulki.SIZE.width - SIZE)
        dx = -dx;
      if (dy > 0 && bar.bump(pos))
        dy = -dy;
      if (pos.y < 0)
        dy = -dy;
      if (pos.y > Kulki.SIZE.height - SIZE) {
        running = false;
      }
    }
  }

  public void draw(Graphics g) {
    if (running) {
      g.setColor(color);
      synchronized (pos) {
        g.fillOval(pos.x, pos.y, SIZE, SIZE);
      }
    }
  }
}

Klasa obiekt = new Klasa();