via Ajaxian.

Ben Alex of Interface 21 has written a detailed post on Java to JavaScript compilation.

The article discusses some of the choices out there (GWT, OpenLaszlo) and goes into an open source alternative called Java2Script Pacemaker.

Spring integration is shown and available for download and it concludes:

J2S promises some attractive benefits for projects that require JavaScript compilation or a web browser implementation of SWT. It also interoperates successfully with a Spring backend. J2S’ deliberate choice to leverage proven existing technologies such as AST and SWT make it a good example of reusing existing code and developer skills, in turn lowering adoption barriers and the prospect of material API change. If you consider yourself an early adopter, SWT devotee, or need a client-centric, web-based user interface that is built upon the mature SWT UI framework, it is definitely worth taking a closer look at J2S.

Does SWT support do it for you?