The above method is in the 2.0 MBean interface for PojoCache. Do you want it there? The interface is really spare, and then this method which seems kind of detailed. Just double checking.
In PojoCacheJmxWrapper it's currently unimplemented. From its name I think it maps to PojoCache.getPojoId(Object pojo), so that's how I'm implementing it. If that's wrong, let me know. If it's right, shouldn't the method name in the mbean interface be getPojoID()?