NetBeans Plugin Quick Start

Welcome to NetBeans plugin development!

This tutorial provides a very simple and quick introduction to the NetBeans plugin development workflow by walking you through the creation of a new toolbar for NetBeans IDE. Once you are done with this tutorial, you will have a general knowledge of how to create, build, and install plugins for NetBeans IDE.

After you finish this tutorial, you can move on to the NetBeans Platform learning trail. The learning trail provides comprehensive tutorials that highlight a wide range of NetBeans APIs for a variety of application types. If you do not want to do a "Hello World" application, you can skip this tutorial and jump straight to the learning trail.

Note: This is not the latest version of this document. Click here to see the most up to date version.


Content on this page applies to NetBeans IDE 6.5, 6.7, 6.8

To follow this tutorial, you need the software and resources listed in the following table.

Software or Resource Version Required
NetBeans IDE version 6.5 or above
Java Developer Kit (JDK) Version 6 or
version 5

Optionally, for troubleshooting purposes, you can download the completed sample and inspect the sources.

The toolbar you create in this tutorial will look as follows:

Google toolbar displaying sample search string

When the user presses Enter in the toolbar above, the IDE's default browser will open and the text in the toolbar will be sent to a Google search, with the results available in the open browser. To create this toolbar, you will use the NetBeans APIs to enhance the IDE's feature set. Specifically, you will create an action that is invoked by a button in the toolbar. You will then create a Swing JPanel containing a JLabel and JTextField as GUI components. Finally, you will implement Presenter.Toolbar to return the JPanel so that it displays in the toolbar, instead of the button.

Setting up the Module Project

When developing the module, you have to make sure the structure of your project is set up correctly. NetBeans IDE provides a Module Project wizard that sets up all of the basic files required for a module.

  1. Choose File > New Project (Ctrl+Shift+N). Under Categories, select NetBeans Modules. Under Projects, select Module. Click Next.
  2. In the Name and Location panel, type GoogleToolbar in the Project Name field. Change the Project Location to any directory on your computer. Leave the Standalone Module option and Set as Main Project checkbox selected. Click Next.
  3. In the Basic Module Configuration panel, type org.myorg.googletoolbar in Code Name Base.
  4. Select "Generate XML Layer". Leave the locations of both the localizing bundle and the XML layer file so that they will be stored in a package with the name org/myorg/googletoolbar. Click Finish.

The IDE creates the GoogleToolbar project. The project contains all of your sources and project metadata, such as the project's Ant build script. The project opens in the IDE. You can view its logical structure in the Projects window (Ctrl+1) and its file structure in the Files window (Ctrl+2).

If you expand the Important Files node, you can open the Module Manifest, which has this content:

Manifest-Version: 1.0
OpenIDE-Module: org.myorg.googletoolbar
OpenIDE-Module-Layer: org/myorg/googletoolbar/layer.xml
OpenIDE-Module-Localizing-Bundle: org/myorg/googletoolbar/
OpenIDE-Module-Specification-Version: 1.0

For details on these NetBeans-specific manifest keys, read the NetBeans Modules API Javadoc description.

Coding the Module

In order to code the module, you need to complete the following steps:

Creating the Action

  1. Right-click the project node and choose New > Action (if Action is not displayed, access it by choosing Other, then in the New File wizard under Categories, select Module Development). Click Next.
  2. In the Action Type panel keep the default setting, which will let the IDE create an action that subclasses ActionListener, as shown below:

    Step 1 of New Action wizard

    Click Next.
  3. In the GUI Registration panel, select File from the Category drop-down list. The Category drop-down list controls where an action is shown in the Keyboard Shortcuts editor in the IDE. Next, deselect Global Menu Item and select Global Toolbar Button. In the Toolbar drop-down list, select File, then in the Position drop-down list, select any position in the drop-down list, such as the one shown below:

    Click Next.
  4. In the Name and Location panel, type GoogleAction as the Class Name and Google Action as the Display Name. Browse to an icon that has a dimension of 16x16 pixels. In fact, you will not use the icon—instead, you will display the JPanel Form that you create in the next section. However, the New Action wizard requires you to specify an icon. Therefore, the icon could be of any dimension, since you will not be using it. Click Finish.

    Note: is added to the org.myorg.googletoolbar package in the Projects window.

Creating the JPanel

In this section, you will create a JPanel which will be the toolbar that you will display as part of the application's main toolbar.

  1. Right-click the project node and choose New > Other. Under Categories, select Swing GUI Forms. Under Projects, select JPanel Form. Click Next.
  2. In the Name and Location panel, type GooglePanel as the Class Name and select the package from the drop-down list. Click Finish. is added to the package and is opened in the Design view in the Source Editor.
  3. Place the cursor at the bottom right-hand corner of the JPanel, then select the JPanel and drag the cursor to resize it, so that its width and length resemble that of a toolbar, as shown below:

    resized JPanel
  4. Drag a JTextField item and a JLabel item from the Palette (Ctrl+Shift+8) directly into the JPanel, then resize the JPanel and the other two items so that they fit snugly together. Finally, click the JLabel and change its text to Google:, then delete the default text in the JTextField. Your JPanel should now resemble the image shown below:

    JTextField and JLabel included in JPanel
  5. Make sure the Property Inspector is open (Window > Navigating > Inspector), then right-click the JTextField and choose Events > Key > keyTyped. This generates a jTextField1KeyTyped() method in the source code, which displays in the Source Editor, as shown below:

    JTextField1KeyTyped() method generated in source code
  6. In the Source Editor, in the Source view of, fill out the jTextField1KeyTyped() method as follows (inserted text shown in bold):
    private void jTextField1KeyTyped(java.awt.event.KeyEvent evt) {
        int i = evt.getKeyChar();
        if (i==10){//The ENTER KEY
            // we display the google url.
                        (new URL(""+jTextField1.getText()+"&btnG=Google+Search"));
            } catch (Exception eee){
                return;//nothing much to do

If you need to, right-click in the Source Editor and choose Format (Alt+Shift+F).

Resolving Errors

Notice that one line of code is underlined in red, indicating errors. This is because required packages have not been imported yet. Place your cursor over the light bulb icon displayed in the column to the immediate left of the red line for URLDisplayer. A tooltip displays, indicating the reason for the error:

tooltip for URLDisplayer error in Source Editor

In order to solve this, you need to make the HtmlBrowser.URLDisplayer class, included in the org.openide.awt package, accessible to your project. To do so, perform the following steps:

  1. Right-click the project node in the Projects window and choose Properties. In the Project Properties dialog that displays, select Libraries under the Categories heading. Then, under Module Dependencies, click the Add button. The Add Module Dependency Dialog displays.
  2. In the filter text box displayed at the top of the Add Module Dependency Dialog, start typing URLDisplayer and notice that the selection of returned modules narrows until the only remaining listing is the UI Utilities API:

    Add Module Dependency dialog displaying the UI Utilities API

    Click OK, then click OK again to exit the Project Properties dialog.
  3. Right-click in the Source Editor and choose Fix Imports (Alt+Shift+F). The Fix All Imports dialog displays, listing suggested paths for unrecognized classes:

    Fix All Imports dialog containing suggested paths for unrecognized classes

    Click OK. The IDE creates the following import statements for
    import org.openide.awt.HtmlBrowser.URLDisplayer;
    Also notice that all errors disappear from the Source Editor.

Implementing Presenter.Toolbar

Because the JPanel you just created is the actual component that will display the Google toolbar, you need to implement Presenter.Toolbar to display it in the toolbar. In, do the following:

  1. Open and notice that it has this content:
    package org.myorg.googletoolbar;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    public final class GoogleAction implements ActionListener {
        public void actionPerformed(ActionEvent e) {
            // TODO implement action body
  2. Change the signature so that Presenter.Toolbar is implemented too, because you want the action to be presented in the toolbar.
    package org.myorg.googletoolbar;
    import java.awt.event.ActionEvent;
    import java.awt.event.ActionListener;
    public final class GoogleAction implements Presenter.Toolbar, ActionListener {
        Component comp  = new GooglePanel();
        public void actionPerformed(ActionEvent e) {
            // TODO implement action body
        public Component getToolbarPresenter() {
            return comp;
  3. Open the layer.xml file and you should see the following:
    <?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE filesystem PUBLIC "-//NetBeans//DTD Filesystem 1.2//EN" "">
        <folder name="Actions">
            <folder name="File">
                <file name="org-myorg-googletoolbar-GoogleAction.instance">
                    <attr name="SystemFileSystem.localizingBundle" stringvalue="org.myorg.googletoolbar.Bundle"/>
                    <attr name="delegate" newvalue="org.myorg.googletoolbar.GoogleAction"/>
                    <attr name="displayName" bundlevalue="org.myorg.googletoolbar.Bundle#CTL_GoogleAction"/>
                    <attr name="iconBase" stringvalue="org/myorg/googletoolbar/icon.png"/>
                    <attr name="instanceCreate" methodvalue="org.openide.awt.Actions.alwaysEnabled"/>
                    <attr name="noIconInMenu" stringvalue="false"/>
        <folder name="Toolbars">
            <folder name="File">
                <file name="org-myorg-googletoolbar-GoogleAction.shadow">
                    <attr name="originalFile" stringvalue="Actions/File/org-myorg-googletoolbar-GoogleAction.instance"/>
                    <attr name="position" intvalue="0"/>

  4. The content shown above was created by the New Action wizard. Delete the "instanceCreate" attribute because you do not want to create an instance of an Action class, in this case. After all, here you want a JPanel to appear there instead.

In this section, you have created a JPanel that will display a JTextField and a JLabel. When Enter is pressed in the JTextField, its content will be sent to a Google search. The HTML browser will open and you will see the result of the Google search. The action class is used to integrate the JPanel within the application's toolbar, as registered in the layer.xml file.

Compiling, Installing and Using the Module

NetBeans IDE uses an Ant build script to compile and install your module in the IDE. The build script was created for you when you created the module project in Setting Up the Module Project above. Now that the module is ready to be compiled and added to the IDE, you can use NetBeans IDE's support for Ant to do so:

  1. In the Projects window, right-click the GoogleToolbar project node and choose Run. The module is built and installed in a new instance of the IDE (i.e., the target platform). By default, the default target platform is the version of the IDE you are currently working in. The target platform opens so that you can try out the new module.
  2. When it is successfully installed, the module adds a new button in the IDE's Edit toolbar.

    Note: The toolbar button does not display an icon. Instead, it displays the JPanel you created in Creating the JPanel above:

    Google toolbar embedded in IDE's Edit toolbar

  3. Type a search string in the text field:

    Google toolbar displaying sample search string
  4. Press Enter. The IDE's default browser starts up, if you have set one in the Options window. The Google URL and your search string are sent to the browser and a search is performed. When the search results are returned, you can view them in the browser.

Sharing the Module

Now that you have built a working module that enhances the IDE, why not share it with other developers? NetBeans IDE offers an easy way to create a binary NetBeans Module file (.nbm) which is a universal means of allowing others to experiment with it in their own versions of the IDE (in fact, this is what you did in Compiling, Installing and Using the Module above).

To create a module binary, do the following:

In the Projects window, right-click the GoogleToolbar project node and choose Create NBM. The new NBM file is created and you can view it in the Files window (Ctrl+2):

new NBM file displayed in the Files window

See Also

This concludes the NetBeans Plugin Quick Start. This document has described how to create a plugin that adds a Google Search toolbar to the IDE. For more information about creating and developing plugins, see the following resources:

Project Features

Project Links

About this Project

Platform was started in November 2009, is owned by Antonin Nebuzelsky, and has 152 members.
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