import java.lang.reflect.ParameterizedType;

import java.lang.reflect.Type;

import java.util.concurrent.Callable;

import java.util.logging.Handler;

import java.util.logging.Logger;

import org.openide.util.Exceptions;

    static Object[] computeOptions(Object previous, Object next) {

        ArrayList<Object> arr = new ArrayList<java.lang.Object>();

        arr.add(previous);

        arr.add(next);

        for (Handler h : Logger.getLogger("").getHandlers()) {

            if (h instanceof Callable<?>) {

                boolean foundCallableForJButton = false;

                for (Type t : h.getClass().getGenericInterfaces()) {

                    if (t instanceof ParameterizedType) {

                        ParameterizedType p = (ParameterizedType)t;

                        Type[] params = p.getActualTypeArguments();

                        if (params.length == 1 && params[0] == JButton.class) {

                            foundCallableForJButton = true;

                            break;

                        }

                    }

                }

                if (!foundCallableForJButton) {

                    continue;

                }

                try {

                    Object o = ((Callable<?>)h).call();

                    assert o instanceof JButton;

                    arr.add(o);

                } catch (Exception ex) {

                    Exceptions.printStackTrace(ex);

                }

            }

        }

        arr.add(DialogDescriptor.OK_OPTION);

        return arr.toArray();

    }

/*

 * The contents of this file are subject to the terms of the Common Development

 * and Distribution License (the License). You may not use this file except in

 * compliance with the License.

 *

 * You can obtain a copy of the License at http://www.netbeans.org/cddl.html

 * or http://www.netbeans.org/cddl.txt.

 *

 * When distributing Covered Code, include this CDDL Header Notice in each file

 * and include the License file at http://www.netbeans.org/cddl.txt.

 * If applicable, add the following below the CDDL Header, with the fields

 * enclosed by brackets [] replaced by your own identifying information:

 * "Portions Copyrighted [year] [name of copyright owner]"

 *

 * The Original Software is NetBeans. The Initial Developer of the Original

 * Software is Sun Microsystems, Inc. Portions Copyright 1997-2006 Sun

 * Microsystems, Inc. All Rights Reserved.

 */

package org.netbeans.core;

import java.util.Arrays;

import java.util.List;

import java.util.concurrent.Callable;

import java.util.logging.Handler;

import java.util.logging.LogRecord;

import java.util.logging.Logger;

import javax.swing.JButton;

import org.netbeans.junit.NbTestCase;

/**

 *

 * @author Jaroslav Tulach

 */

public class NotifyExcPanelTest extends NbTestCase {

    Logger main;

    public NotifyExcPanelTest(String testName) {

        super(testName);

    }

    protected void setUp() throws Exception {

        main = Logger.getLogger("");

        for (Handler h : main.getHandlers()) {

            main.removeHandler(h);

        }

    }

    public void testHandlesThatImplementCallableForJButtonAreIncluded() throws Exception {

        class H extends Handler 

        implements Callable<JButton> {

            public JButton button = new JButton("Extra");

            public void publish(LogRecord arg0) {

            }

            public void flush() {

            }

            public void close() throws SecurityException {

            }

            public JButton call() throws Exception {

                return button;

            }

        } // end of H

        H handler = new H();

        main.addHandler(handler);

        List<Object> options = Arrays.asList(NotifyExcPanel.computeOptions("prev", "next"));

        assertTrue("Contains our button: " + options, options.contains(handler.button));

    }

    public void testHandlesThatImplementCallableForOtherObjectsAreNotIncluded() throws Exception {

        class H extends Handler 

        implements Callable<Object> {

            public JButton button = new JButton("Extra");

            public void publish(LogRecord arg0) {

            }

            public void flush() {

            }

            public void close() throws SecurityException {

            }

            public JButton call() throws Exception {

                return button;

            }

        } // end of H

        H handler = new H();

        main.addHandler(handler);

        List<Object> options = Arrays.asList(NotifyExcPanel.computeOptions("prev", "next"));

        assertFalse("Does not contain our button: " + options, options.contains(handler.button));

    }

}

        <li><api type='import' group='java' category='friend' name='uihandler-hooks' >

                This module makes on of its <code>Handler</code> implement

                <code>Callable&lt;JButton&gt;</code> which is a signal for

                core providing the exception dialog to include such a 

                <code>JButton</code> in its list of options. That way this 

                module can enhance the dialog with "Report..." button.

            </api>

        </li>            

MSG_SubmitButton=Report...

                    LOG.log(Level.INFO, url.toExternalForm(), ex);

                    url = getClass().getResource("UnknownHostException.html");

                    continue;

                } catch (java.net.NoRouteToHostException ex) {

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.util.concurrent.Callable;

import javax.swing.JButton;

import org.openide.util.NbBundle;

    }

    private JButton button;

    public JButton call() throws Exception {

        if (button == null) {

            button = new JButton(NbBundle.getMessage(UIHandler.class, "MSG_SubmitButton")); // NOI18N

            button.addActionListener(this);

        }

        return button;

    }

    public void actionPerformed(ActionEvent ev) {

        run();