In recent months there has been an initiative underway called Rootbeer, which is a GPU compiler for Java code. Rootbeer claims to be more advanced than CUDA or OpenCL bindings for Java as it does static code analysis of the Java Bytecode and takes it automatically to the GPU.
The MIT-licensed Rootbeer compiler weighs in at 20k lines of code for Windows and Linux. Rootbeer allows for all major Java code to be executed on the graphics processor in a seamless manner without explicitly targeting the graphics processor at development time. The code is written by a Phil Pratt-Szeliga of Syracuse University.
The goal of this work is to bring high-performance GPU computing to Java with minimal effort from the developer. More information on the Rootbeer Java project is available from its GitHub page