Honest question: In your mind, is there a difference between a developer and a programmer? Does the programmer get his/her hands dirty adjusting the nuts and bolts in the depths of the language at its interface with the hardware while the developer uses tools (frameworks?) built by programmers, enabling them to stay at arm's length from the details, unconcerned about what's happening under the hood?
The multi-threading concept you describe would not be that hard to program and would be an interesting, confidence-building exercise for someone who may not be too sure of their threading skills. You can find some very good multi-threading tutorials and discussions by searching "java concurrency".
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Please do not post multiple threads on the same topic.