netbeans.apache.org/src/content/wiki/DevFaqCustomizingUnexpectedExceptionDialog.asciidoc

// 
//     Licensed to the Apache Software Foundation (ASF) under one
//     or more contributor license agreements.  See the NOTICE file
//     distributed with this work for additional information
//     regarding copyright ownership.  The ASF licenses this file
//     to you under the Apache License, Version 2.0 (the
//     "License"); you may not use this file except in compliance
//     with the License.  You may obtain a copy of the License at
// 
//       http://www.apache.org/licenses/LICENSE-2.0
// 
//     Unless required by applicable law or agreed to in writing,
//     software distributed under the License is distributed on an
//     "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
//     KIND, either express or implied.  See the License for the
//     specific language governing permissions and limitations
//     under the License.
//

= DevFaqCustomizingUnexpectedExceptionDialog
:jbake-type: wiki
:jbake-tags: wiki, devfaq, needsreview
:jbake-status: published
:keywords: Apache NetBeans wiki DevFaqCustomizingUnexpectedExceptionDialog
:description: Apache NetBeans wiki DevFaqCustomizingUnexpectedExceptionDialog
:toc: left
:toc-title:
:syntax: true

== How can I customize the Unexpected Exception dialog ?

Problem: How do I add new functionality to the Unexpected Exception dialog?

Solution: First, one needs to create a new class as follows.

The first part of this class is that it must extend `Handler`:  

[source,java]
----

public class NewFunctionExceptionHandler extends Handler {


    @Override
    public void publish(LogRecord record) {
        if (record.getThrown() != null) {
            // This is an uncaught exception being thrown.
        }
    }

    @Override
    public void flush() {
    }

    @Override
    public void close() throws SecurityException {
    }
}
----

In order to properly process the exceptions, one must do a check for the exception in the `publish()` method; `LogRecord`s created due to exceptions being thrown will always have `Throwable`s present.

This class also must implement `Callable<JButton>`.  The button we want displayed in the Uncaught Exception dialog needs to be returned in the call() method:

[source,java]
----

public class NewFunctionExceptionHandler extends Handler implements Callable<JButton> {


    @Override
    public void publish(LogRecord record) {
        if (record.getThrown() != null) {
            // This is an uncaught exception being thrown.
        }
    }

    @Override
    public void flush() {
    }

    @Override
    public void close() throws SecurityException {
    }

    // Return the button we want to be displayed in the Uncaught Exception Dialog.
    @Override
    public JButton call() throws Exception {
        ...
    }
}
----

The JButton's action listener needs to be passed the LogRecord that passed via the `publish()` method. Then, within said action listener for the button, the developer can do what is needed with that record (e.g. Open a Top Component to email a bug report or do anything else).

The final result will look similar to:

[source,java]
----

public class NewFunctionExceptionHandler extends Handler implements Callable<JButton> {

    private JButton newFunctionButton;
    private NewFunctionActionListener newFunctionActionListener = new NewFunctionActionListener();

    @Override
    public void publish(LogRecord record) {
        if (record.getThrown() != null) {
            newFunctionActionListener.setLogRecord(record);
        }
    }

    @Override
    public void flush() {
    }

    @Override
    public void close() throws SecurityException {
    }

    // Return the button we want to be displayed in the Uncaught Exception Dialog.
    @Override
    public JButton call() throws Exception {
        if (newFunctionButton == null) {
            newFunctionButton = new JButton("Review and Submit Issue");
            newFunctionButton.addActionListener(newFunctionActionListener);
        }

        return reviewIssueButton;
    }

    private class NewFunctionActionListener implements ActionListener {

        private LogRecord logRecord;

        public NewFunctionActionListener() {
        }

        @Override
        public void actionPerformed(ActionEvent e) {
            // Close our Uncaught Exception Dialog first.
            SwingUtilities.windowForComponent(reviewIssueButton).setVisible(false);
        }

        public void setLogRecord(LogRecord logRecord) {
            this.logRecord = logRecord;
        }
    }
}
----

To register this exception handler, one only needs to add the new `Handler` to a `java.util.Logger` named with the empty string:

[source,java]
----

   Logger.getLogger("").addHandler(new NewFunctionExceptionHandler());
----

Any `Handler` attached to the "" Logger that also `implements Callable<JButton>` will have its button displayed in the Uncaught Exception Dialog.

This could be done in a module's `Installer` class.

Applies to: NetBeans IDE 6.0 and newer

Platforms: All

=== Apache Migration Information

The content in this page was kindly donated by Oracle Corp. to the
Apache Software Foundation.

This page was exported from link:http://wiki.netbeans.org/DevFaqCustomizingUnexpectedExceptionDialog[http://wiki.netbeans.org/DevFaqCustomizingUnexpectedExceptionDialog] , 
that was last modified by NetBeans user Skygo 
on 2013-12-17T22:39:45Z.


*NOTE:* This document was automatically converted to the AsciiDoc format on 2018-02-07, and needs to be reviewed.