Java Programming Tutorial - 54 - Event Handler Program

import javax.swing.JFrame;

public class apples {
   public static void main(String[] args){

      tuna bucky = new tuna();
      bucky.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      bucky.setSize(350, 100);
      bucky.setVisible(true);
   }
}

import java.awt.FlowLayout;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JFrame;
import javax.swing.JTextField;
import javax.swing.JPasswordField;
import javax.swing.JOptionPane;

public class tuna extends JFrame{

   private JTextField item1;
   private JTextField item2;
   private JTextField item3;
   private JPasswordField passwordField;

   public tuna(){
      super("The title");
      setLayout(new FlowLayout());

      item1 = new JTextField(10);
      add(item1);

      item2 = new JTextField("enter text here");
      add(item2);

      item3 = new JTextField("uneditable", 20);
      item3.setEditable(false);
      add(item3);

      passwordField = new JPasswordField("mypass");
      add(passwordField);

      thehandler handler = new thehandler();

      item1.addActionListener(handler);
      item2.addActionListener(handler);
      item3.addActionListener(handler);
      passwordField.addActionListener(handler);
   }

   private class thehandler implements ActionListener{

      public void actionPerformed(ActionEvent event){
         String string = "";

         if(event.getSource()==item1)
               string=String.format("field 1: %s",event.getActionCommand());
         else if (event.getSource()==item2)
               string=String.format("field 2: %s",event.getActionCommand());
         else if (event.getSource()==item3)
               string=String.format("field 3: %s",event.getActionCommand());
         else if (event.getSource()==passwordField)
               string=String.format("password field is: %s",event.getActionCommand());

         JOptionPane.showMessageDialog(null, string);
      }
   }
}