In order to integrate this library i just change these lines;

org.bridj.BridJ.register()

Line 192:

Class<?> type = Class.forName(name, false, Platform.getClassLoader());

org.bridj.Platform.getClassLoader()

Line 93:

return Thread.currentThread().getContextClassLoader();

Just as suggestion, i have not tested in other environment, but it works fine in grails development environment.