Integrating an Applet in a Web Application
An applet is a program written in the Java programming
language that can be included in an HTML page, much in the same way
an image is included in a page. The application that you build
in this tutorial shows you how to build and deploy applets in the IDE.
Note: Though there are no project templates that are specifically
designed for creating applets in the IDE, you can easily develop them in
a Java project and package them in a web project, as shown in this tutorial.
Contents
To follow this tutorial, you need the following software and resources.
Creating or Importing an Applet Source File
In this section, you create your first applet. Possibly, you already
have an applet and, in this case, you can use the instructions below to import
it into the IDE.
Create the Java project from scratch or from existing sources
- Choose File > New Project (Ctrl-Shift-N).
Under Categories, select Java.
- Choose one of the following:
- If you are creating a new applet source file, select Java Class Library
under Projects. Click Next.
- If you want to import an applet source file, select Java Project with Existing Sources.
Click Next. Specify the file's location in the
Source Packages Folder text box.
- Under Project Name, type HelloApplet. Change the
Project Location to any folder on your computer.
- Click Finish. If you imported an applet source file, run it.
Create the applet source file
- Right-click the HelloApplet project and choose Properties to open the Properties window.
- Select the desired Source / Binary Format for the project and click OK.
Note: For example, if you choose JDK 6 the applet might not run
on machines that have an older version of the JRE or Java browser plugin.
- Right-click the HelloApplet project node in the Projects window
and select New > Other (Ctrl-N).
- Under Categories, select Java. Under File Types,
select Applet.
Alternatively, if you want to visually design your applet, select Swing GUI Forms > JApplet Form.
Click Next.
- Under Class Name, type MyApplet. Under
Package, type org.me.hello.
- Click Finish.
The IDE creates the applet source file in the
specified package. The applet source file opens in the Source editor.
- Define your applet class by copying and pasting the following
code over the existing default code:
package org.me.hello;
import java.applet.Applet;
import java.awt.Graphics;
public class MyApplet extends Applet {
@Override
public void paint(Graphics g) {
g.drawString("Hello applet!", 50, 25);
}
}
Alternatively, if you are designing an Applet Form instead, use the Designing a Swing GUI in NetBeans IDE document to create something like the following:

For detailed information on writing applets, see The JavaTM Tutorial's
Applets section.
Running an Applet Source File
The applet that you created can be run from the IDE. This section shows you how to do so.
Build and run the applet source file
Right-click the MyApplet.java file node in the Projects
window and choose Run File from the contextual menu. The MyApplet.html launcher file,
with the applet embedded, is created
in the build folder, which you can
see if you switch to the Files window (Ctrl-2):

The applet is launched in the Applet Viewer:

Applet forms are also displayed in the Applet Viewer:

Embedding an Applet in a Web Application
Your applet is complete. Now you need to make it available
to the user. To do so, you create a web application, put the applet JAR
on its classpath, and then add an applet tag to the web application's HTML file.
Create the web project
- Choose File > New Project.
- Select Web Application in the Java Web category. Click Next.
- Under Project Name, type HelloWebApplet.
- Change the Project Location to any folder on your computer. Click Next.
- Select the target server. Click Finish.
Add the applet JAR file to the web project
When you want to include an applet JAR file in a web project,
you can do so by adding the Java project that contains the JAR file, or by
adding the JAR file itself. Although the choice is yours, note that when you add the
Java project to the web project, you enable the IDE to build
the applet whenever you build the web application. Therefore, when you
modify the applet in the Java project, the IDE builds a new version
of the applet whenever the web project is built. On the other hand, if the applet
JAR file is not in a NetBeans IDE project, the applet source file is not rebuilt
when you build the web project.
Note: At this point, if you are using the HelloApplet project in the IDE, there is no HelloApplet.jar file. This is OK. The HelloApplet.jar file will be built when you build the HelloWebApplet project.
- In the Projects window, right-click the HelloWebApplet project node and select
Properties from the contextual menu.
- Select the Packaging category.
- Choose one of the following:
- Confirm that the JAR that contains the applet source file is listed in the table in the Project Properties window. Click OK.
By default, the applet JAR file will be copied to the web application's web page library,
which is the build/web folder. The build/web folder is the root directory of the application and
is displayed as "/" in the Path in WAR column of the table.
You can modify the location of the applet in the WAR by
typing a new location for the applet in the Path in WAR column.
- Click Close to close the Project Properties window.
When you build the HelloWebApplet project by choosing Run > Build Project (HelloWebApplet) from the main IDE's menu, the applet's JAR file is generated in the original HelloApplet project and is packaged in the HelloWebApplet project's WAR file. It is also added to the build/web
folder. You can follow this process in the Output window and see the results in the Files window.

Create and run the JSP file or HTML file
- Choose one of the following:
- If you want to embed the applet in a JSP file, double-click the default index.jsp file in the Projects window.
This file is created by the IDE when you create a web project. It opens in the Source Editor.
- If you want to embed the applet in an HTML file, right-click the HelloWebApplet project node, and choose New > Other from
the contextual menu. Under Categories, select Web. Under File Types, select HTML. Click Next. Give your
HTML file a name, select the Web folder for its location, and click Finish.
- Embed the applet in the file by adding the following applet tag anywhere
between the file's <body></body> tags:
- In an HTML file: <applet code="org.me.hello.MyApplet" archive="HelloApplet.jar"></applet>
- In a JSP file: <applet code="org.me.hello.MyApplet" archive="HelloApplet.jar" width="600" height="480"/>
Notes.
- For this tutorial you can ignore the hint glyph in the left margin if you are adding the
applet code to an HTML file.
- org.me.hello.MyApplet is the full classname to your applet.
- HelloApplet.jar is the JAR file that contains the applet.
- Right-click the JSP node or HTML node in the Projects window
and choose Run File from the contextual menu.
The server deploys the JSP file or HTML file in the IDE's default browser.
You should see something
similar to the illustration below (after you allow to run the application by clicking Run in the Security Warning dialog box):

For applet forms, you should see something similar to the following:
