import javax.swing.*;      // swing classes
/**
 * Very simple demo of Swing event handling.  
 * Create a window with a single button that prints a message when it's clicked.
 * Version 2 with anonymous inner class to handle button events.
 */ 
public class ButtonDemo3 {
  static int nEvents = 0;

  public static void main(String[] args) {
    // Create new window and set it to exit from application when closed
    JFrame frame = new JFrame("Button Demo");
    frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    
    // create a new button with label "Hit me" and string "OUCH!" to be
    // returned as part of each action event
    JButton button = new JButton("Hit me");
    button.setActionCommand("OUCH!");
    
    // Create and register a new button listener to handle clicks
    button.addActionListener(
      e -> {
    	nEvents++;
    	System.out.println("OUCH! " + nEvents);
    });
    
    // Add button to the window and make it visible
    frame.add(button);
    frame.pack();
    frame.setVisible(true);
  }
}