In keeping with Sun's promise to provide more tools for desktop and client-side developers, the company has been working for some time on bringing Java WebStart and applets together. The first fruits of that effort are available in Java SE 6 Update 10, currently in beta.

One result of a unified architecture across browser-based applets and locally installed desktop applications is that applets can optionally use their own JREs, and run inside the sandbox specific to that JRE instance. That enables applets with all kinds of features hitherto available only to desktop applications, including much of the WebStart APIs, such as file access and limited access to other client resources.

One of the most interesting demos at JavaOne 2008 was a direct result of the new applet and WebStart architecture: Draggable applets. That features enables a user to locally install an applet by dragging it from a Web page onto the desktop. The applet thenceforth will act as local application, no longer requiring a browser process.

In a recent Sun Developer Network article, The New Draggable Applet Feature in the Java SE 6 Update 10 Plug-In, Roger Yeung provides a detailed tutorial on how to develop and deploy draggable applets. As the tutorial explains, no programming changes are required of the applets to enable this feature.

As a Java technology developer, you can use the rich functionalities in the Java platform to create an applet and allow the user to bring your applet to the desktop. This feature increases flexibility in application deployment and takes advantage of Java Web Start technology to increase the ease of deploying Java Network Launching Protocol (JNLP) applets...

Because the Java Plug-in uses Java Web Start technology, when the user closes the web page, you can prompt the user to decide whether to create a shortcut on the desktop. With the shortcut, the user can now directly launch your applet without opening a web browser and searching for your applet.

While even existing applets can benefit from this feature, new methods were added to the Applet class that afford the applet a chance to be notified of dragging-related lifecycle events.

Unfortunately, Java SE 6 Update 10 is available only for Windows, Linux, and Solaris, and the new applet features only work with Firefox 3 and IE 6 and 7.

What do you think of the new applet features in Java SE 6 Update 10?