gistfile1.java

package doglax;

import java.awt.GridLayout;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.lang.reflect.Field;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JTextField;

/**
 *
 * @author netmask
 */
public class Main extends JFrame {

    private JTextField jtextField1;
    private JTextField jtextField2;
    private JTextField jtextField3;
    private boolean actived = true;

    public Main() {
        setLayout(new GridLayout());
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setSize(300, 200);


        jtextField1 = new JTextField();
        jtextField2 = new JTextField();
        jtextField3 = new JTextField();

        add(jtextField1);
        add(jtextField2);
        add(jtextField3);

        JButton button = new JButton("Activar");
        button.addMouseListener(new MouseListener() {

            public void mouseClicked(MouseEvent e) {
                //tiene que ser un metodo aparte para tener visible la instancia de Main
                desactivarFields();
            }

            public void mousePressed(MouseEvent e) {
            }

            public void mouseReleased(MouseEvent e) {
            }

            public void mouseEntered(MouseEvent e) {
            }

            public void mouseExited(MouseEvent e) {
            }
        });

        add(button);

    }

    private void desactivarFields() {
        //aqui ta la magia
        //Iteramos entre todas las propiedades de la classe
        for (Field field : Main.class.getDeclaredFields()) {
            try {
                // por si esta declarada private
                field.setAccessible(true);
                //si en la instancia de  this (Main) el campo es instancia de Jtextfield, se desavilita
                if (field.get(this) instanceof JTextField) {
                    JTextField jfield = (JTextField) field.get(this);
                    jfield.setEditable(actived ? false : true);
                }

            } catch (Exception ex) {
                ex.printStackTrace();
            }

        }

        actived = false;

    }

    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        java.awt.EventQueue.invokeLater(new Runnable() {

            public void run() {
                new Main().setVisible(true);
            }
        });
    }
}