Want to add a feature or automate something in your NetBeans IDE? Follow along as we write your first plugin for NetBeans.

Let's go beyond the simple Toolbar Example and create a plugin which can auto-update itself. This code is based on the WakaTime plugin for NetBeans. Our example plugin will simply print a Hello World statement and update to new versions if available... just enough to get you started.

## Create a new Plugin Project

Choose `File` -> `New Project` then `NetBeans Modules` -> `Module` as the project type.

Name your project

Choose a namespace or code name for your plugin

## Add a Java File

## Plugin Starting Point

After creating the new Java Class file, make it extend ModuleInstall and wrap it with @OnShowing so it only runs after the GUI has loaded.

`java @OnShowing public class MyPlugin extends ModuleInstall implements Runnable { }`

Press `ALT` + `ENTER` with your cursor over `OnShowing` then select `Search Module Dependency for OnShowing` to import the Window System API into the project. This will add a new dependency to your project as well as add the necessary import statements to the top of your file. Also do this for `ModuleInstall`.

Sometimes NetBeans misses the `org.openide.util` dependency, so you might have to add that one manually. To do that, right click on MyPlugin then select `Properties`.

Choose category `Libraries` then click `Add...`. Type `org.openide.util` then click `OK`. This will add the dependency to your `project.xml` file.

Press `ALT` + `ENTER` on your MyPlugin class, then choose `Implement all abstract methods`.

One last thing, add this line to your `manifest.mf` file.

`OpenIDE-Module-Install: org/myorg/myplugin/MyPlugin.class`

Now the `run()` method will execute after your plugin has loaded.

## Logging

Let's make that `println` output to the NetBeans IDE log. First, setup the logger as an attribute of your MyPlugin class.

`java public static final Logger log = Logger.getLogger("MyPlugin");`

Press `ALT` + `ENTER` to import java.util.logging.Logger.

Replace `println` with `log.info("MyPlugin has loaded.");`.

## Updating Your Plugin Automatically

Create a new Java file `UpdateHandler.java` inside your MyPlugin package.

Replace the contents of this file with UpdateHandler.java. Search the module dependency and add any missing dependencies by pressing `ALT` + `ENTER` over each import statement.

Add these lines to your `manifest.mf` file.

`java OpenIDE-Module-Layer: org/myorg/myplugin/layer.xml OpenIDE-Module-Implementation-Version: 201501010101`

Create a new XML document in your MyPlugin package.

`java <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE filesystem PUBLIC "-//NetBeans//DTD Filesystem 1.2//EN" "http://www.netbeans.org/dtds/filesystem-1_2.dtd"> <filesystem> <folder name="Services"> <folder name="AutoupdateType"> <file name="org_myorg_myplugin_update_center.instance"> <attr name="displayName" bundlevalue="org.myorg.myplugin.Bundle#Services/AutoupdateType/org_myorg_myplugin_update_center.instance"/> <attr name="enabled" boolvalue="true"/> <attr name="instanceCreate" methodvalue="org.netbeans.modules.autoupdate.updateprovider.AutoupdateCatalogFactory.createUpdateProvider"/> <attr name="instanceOf" stringvalue="org.netbeans.spi.autoupdate.UpdateProvider"/> <attr name="url" bundlevalue="org.myorg.myplugin.Bundle#org_myorg_myplugin_update_center"/> </file> </folder> </folder> </filesystem>`

Add this code to your MyPlugin class inside the `run()` method.

`java WindowManager.getDefault().invokeWhenUIReady(new Runnable () { @Override public void run() { UpdateHandler.checkAndHandleUpdates(); } });`

Add these lines to your `Bundle.properties` file:

`java Services/AutoupdateType/org_myorg_myplugin_update_center.instance=MyPlugin UpdateHandler.NewModules=false org_myorg_myplugin_update_center=https\://example.com/updates.xml`

Now every time NetBeans restarts and launches your plugin, it will check for updates by downloading `updates.xml` from example.com.

Your updates.xml file tells NetBeans where to get the new NBM of your plugin. To create an NBM for publishing your plugin, right click on your MyPlugin project and select `Create NBM`. The NBM file is what you will publish to the NetBeans Plugin Portal.

For an example of hosting `updates.xml` on GitHub, look at update.xml and corrosponding Bundle.properties from the WakaTime NetBeans plugin.