This can be done much more effectively than just “hey does anyone know Java?” Something like “Hey I’m having trouble with X. Is anyone able to take a look?” is

This can be done much more effectively than just “hey does anyone know Java?” Something like “Hey I’m having trouble with X. Is anyone able to take a look?” is much better since you’re actually describing your ask. Sure, I may know Java, but I may not know the answer to your problem.