Look here
http://www.chainkey.com/en/jcp/compare.htm

>Very interesting, mainly focus on automatic trial key method and purchase keys and also this most important:
>
>Compatible with all major obfuscators
>Locks your Java application to prevent software piracy.
>
>but, they are focus on trial keys, their business is the selling of the trial keys and in second option the source code protection (obfuscation).
>
>Trialware4j is an option, there is a light at the end of the tunnel.
>
>Qestions. If we are going to adopt Java like the programing tool, what will be the most suitable way to do web comertial apps ? maybe using protected applets ?