Rich internet applications (RIA) are applications that have traits similar to desktop applications, but are deployed via the internet. RIAs may be developed and deployed as applets or Java Web Start applications.

• Applets - Applets run in the context of a browser. The Java Plug-in software controls the execution and lifecycle of applets.
• Java Web Start applications - Java Web Start applications are launched via a browser the first time. They may subsequently be launched from a desktop shortcut. Once a Java Web Start application is downloaded and its security certificate has been accepted by the user, it behaves almost like a standalone application.

Component-Based Architecture

In the past, the decision of whether to deploy a Java rich internet application inside the browser as an applet, or outside the browser as a Java Web Start application, could significantly impact the design of the application. With the next generation Java Plug-in, this decision has been greatly simplified.

Traditionally, applications construct their user interfaces, including the top-level Frame, in the main method. This programming style prevents easy re-deployment of the application in the browser, because it assumes that the application creates its own Frame. When running in the browser as an applet, the applet is the top level container that should hold the user interface for the application. A top-level Frame is not needed.

Use component-based architecture when designing your rich internet application. Try to organize its functionality into one or more components that can be composed together. In this context, the term "component" refers to a GUI element that is a subclass of the AWT Component class, the Swing JComponent class, or another subclass. For example, you could have a top level JPanel which contains other UI components in it (like a combination of more nested JPanels and text fields, combo boxes etc.). With such a design, it becomes relatively easy to deploy the core functionality as an applet or a Java Web Start application.

To deploy as an applet, you just need to wrap the core functionality in an Applet or JApplet and add the browser specific functionality, if necessary. To deploy as a Java Web Start application, wrap the functionality in a JFrame.

Choosing Between Applets and Java Web Start Applications

The Rich Internet Applications Decision Guide contains detailed information to help you decide whether to deploy your code as an applet or Java Web Start application.

This trail discusses the development and deployment of RIAs.

Developing and Deploying Applets

Developing and Deploying Java Web Start Applications

Doing More With Rich Applications

Deployment In-Depth

Supporting Tools

Packaging Programs in JAR Files