MouseListener

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

public class MouseListenerExample implements MouseListener
{
    JFrame frame;
    JButton button;
    int i;

    MouseListenerExample()
    {
        i = 0;

        button = new JButton("Cliccami");
        button.setVisible(true);
        button.setBounds(250, 150, 105, 30);
        button.addMouseListener(this);

        frame = new JFrame("In ascolto del mouse...");
        frame.add(button);
        frame.setLayout(null);
        frame.setSize(600, 500);
        frame.setVisible(true);
    }

    @Override
    public void mouseClicked(MouseEvent e)
    {
        System.out.println("Click!");
    }

    @Override
    public void mousePressed(MouseEvent e)
    {
        i++;
        JOptionPane.showMessageDialog(null, String.format("Hai cliccato %d volte", i), "...", JOptionPane.INFORMATION_MESSAGE);
        switch (i)
        {
            case 0:
                frame.getContentPane().setBackground(Color.BLACK);
                break;
            case 1:
                frame.getContentPane().setBackground(Color.BLUE);
                break;
            case 2:
                frame.getContentPane().setBackground(Color.CYAN);
                break;
            case 3:
                frame.getContentPane().setBackground(Color.GRAY);
                break;
            case 4:
                frame.getContentPane().setBackground(Color.GREEN);
                break;
            case 5:
                frame.getContentPane().setBackground(Color.LIGHT_GRAY);
                break;
            case 6:
                frame.getContentPane().setBackground(Color.MAGENTA);
                break;
            case 7:
                frame.getContentPane().setBackground(Color.ORANGE);
                break;
            case 8:
                frame.getContentPane().setBackground(Color.PINK);
                break;
            case 9:
                frame.getContentPane().setBackground(Color.RED);
                break;
            case 10:
                frame.getContentPane().setBackground(Color.WHITE);
                break;
            case 11:
                frame.getContentPane().setBackground(Color.YELLOW);
                break;
        }
    }

    @Override
    public void mouseReleased(MouseEvent e)
    {
        System.out.println("Out!");
    }

    @Override
    public void mouseEntered(MouseEvent e)
    {
        System.out.println("Ora sei sopra...");

    }

    @Override
    public void mouseExited(MouseEvent e)
    {
        System.out.println("Ora sei lontano...");
    }
}