Canoo Offers Free Portlet Integration

Swiss company Canoo, is offering developers a free portlet integration code that can be used with Canoo’s UltraLightClient to create and run Rich Internet Applications as portlets on a portal server.

UltraLightClient is an add-on library for Swing and J2EE that delegates tasks to the standard J2EE/J2SE infrastructure, using Swing on the client, standard communication protocols set by the J2EE container, and standard lifecycle management on the server. UltraLight Client features pause and resume functionality, so that a user session can be stopped and restarted. It can be used to deploy UltraLightClient-based apps as portlets, according to JSR 168.

Portlets are defined by the Java Specification Request 168, an emerging standard to develop Web portals. Portal servers reload the entire browser page when a server roundtrip happens, meaning portlets must save and refresh the state of their user interface. This process makes it difficult for rich clients to maintain their state on the client side.

The UltraLightClient portlet, on the client side, is displayed in an applet, which is discarded and restarted when a browser page is reloaded. By calling “pause” when the applet is discarded, and “resume” after restarting, the user interface status still exists after the server roundtrip.

According to Canoo, UltraLightClient-based rich-client portlets share the development infrastructure, as well as the production platform between HTML and rich-client applications. Customers will be able to write a rich-client user interface for an HTML application or vice versa by rewriting the presentation layer. HTML and rich-client user interfaces can communicate by sharing the same session context. Swing allows Java programmers to develop user interfaces without HTML’s limitations.

UltraLightClient-based rich-client portlets works with Swing widgets and a homogenous Java-based programming model, rather than a mix of JSP, servlets, HTML, Struts, Java and other technology.

Portlet integration is available at the UltraLightClient community site (, and runs with any portlet server that complies with JSR 168.

About the Author

Kathleen Ohlson is senior editor at Application Development Trends magazine.