ja9

1. Write a Java program to create a thread for moving a ball inside a panel vertically. The
   ball should be created when the user clicks on the start button. [15 M]
   import javax.swing.;
   import java.awt.;
   import java.awt.event.*;

public class BallPanel extends JPanel implements ActionListener {
private int ballY = 0;
private Timer timer;

public BallPanel() {
    timer = new Timer(100, this);
}

public void startAnimation() {
    timer.start();
}

public void actionPerformed(ActionEvent e) {
    ballY += 5;
    if (ballY > getHeight()) {
        ballY = 0;
    }
    repaint();
}

protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    g.setColor(Color.RED);
    g.fillOval(getWidth() / 2 - 10, ballY, 20, 20);
}

public static void main(String[] args) {
    JFrame frame = new JFrame();
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    BallPanel panel = new BallPanel();
    JButton startButton = new JButton("Start");
    startButton.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            panel.startAnimation();
        }
    });
    frame.add(startButton, BorderLayout.NORTH);
    frame.add(panel, BorderLayout.CENTER);
    frame.setSize(400, 400);
    frame.setVisible(true);
}

}

2. Write a Java program using Spring to display the message “If you can't explain it
   simply, you don't understand it well enough”.
   import org.springframework.context.ApplicationContext;
   import org.springframework.context.annotation.AnnotationConfigApplicationContext;
   import org.springframework.context.annotation.Bean;
   import org.springframework.context.annotation.Configuration;

@Configuration
public class SpringMessageApp {
@Bean
public String message() {
return "If you can't explain it simply, you don't understand it well enough.";
}

public static void main(String[] args) {
    ApplicationContext context = new AnnotationConfigApplicationContext(SpringMessageApp.class);
    String message = context.getBean("message", String.class);
    System.out.println(message);
}

}