To have Java running on top of Pharo (which means on top of Cog), you would need to have as they did in STX, a JIT compatible with java bytecode, an interpreter for java bytecode, runtime objects such as JavaContext, ... It is at least 1 year of work for an expert in virtual machines (I think there's mainly 1 expert in the Cog VM but there are several on java VM). Therefore this project requires several hundred thousands dollars (considering you can find a virtual machine expert willing to do it). A bit too much for ESUG in my opinion.