NetBeans Module Quick Start Tutorial

This document demonstrates how to create a module that adds a Google Search toolbar to the IDE or to any other application based on the NetBeans Platform. It will look as follows:

Google toolbar displaying sample search string

To do so, you use the NetBeans APIs to enhance the application's feature set. Specifically, you create an action that is invoked by a button in the toolbar. You then create a Swing JPanel containing a JLabel and JTextField as GUI components. Finally, you override the action's getToolbarPresenter() method to return the JPanel so that it displays in the toolbar, instead of the button. When the module is installed, the user types a search string in the JTextField and presses Enter, at which point the URLDisplayer class is used to send the string to the IDE's default browser. The browser opens and displays the Googled results of the user's search string.


Content on this page applies to NetBeans IDE 6.0

For more information on working with modules, see NetBeans Module and Rich Client Application Development on the NetBeans website. If you have questions, visit the NetBeans Developer FAQ or use the feedback link at the bottom of this document.

Installing the Software

Before you begin, you need to install the following software on your computer:

Installing the Sample

To see the end result of this tutorial, install the sample module and test the Google toolbar in the IDE:

  1. Download and unzip the attached file.
  2. In the IDE, choose File > Open Project (Ctrl+Shift+O) and browse to the location of the unzipped file. Select the module project and click Open Project Folder. The module project opens in the IDE and you should see the following in the Projects window (expand nodes as necessary):

    Source files displayed in Projects window
  3. Right-click the project node and choose Install/Reload in Target Platform. By default, the target platform is the IDE in which you are developing your module project. The target platform opens and the module is installed.
  4. Verify that the module is correctly installed by testing its functionality as described below in Using the Module.

Now that you know what the end result looks like, you can create the module from scratch and learn about each part while creating it.

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 Plug-in Modules. Under Projects, select Module Project. 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, replace yourorghere in Code Name Base with myorg, so that the whole code name base is org.myorg.googletoolbar. Leave the locations of the localizing bundle and XML layer, that way 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). For example, the Projects window should now look as follows:

logical structure displayed in Projects window.

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 NetBeans Module Development). Click Next.
  2. In the Action Type panel keep the default setting, which will let the IDE create an action that subclasses CallableSystemAction, as shown below:

    Step 1 of New Action wizard

    Click Next.
  3. In the GUI Registration panel, select Edit 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 Edit, then in the Position drop-down list, select Find... - HERE, as shown below:

    Step 2 of New Action wizard

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

Creating the JPanel

  1. Right-click the project node and choose New > Other. Under Categories, select Java 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 Reformat Code (Ctrl+Shift+F).

Resolving Errors

Notice that several lines of code are 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.

Overriding getToolbarPresenter()

Because the JPanel you just created is the actual component that will display the Google toolbar, you need to override the getToolbarPresenter() method in the action class. In, do the following:

  1. Beneath the class declaration, declare and set the following variable:
    GooglePanel retValue = new GooglePanel();
  2. Define the getToolbarPresenter() method to return the retValue variable:
    public java.awt.Component getToolbarPresenter() {
        return retValue;

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 Install/Reload in Target Platform. 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 however that 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. 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 own versions of the IDE (in fact, this is what you did in Installing the Sample 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
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Next Steps

This concludes the NetBeans Google Toolbar Module tutorial. This document has described how to create a module that adds a Google Search toolbar to the IDE. For more information about creating and developing modules, see the following resources: