Java update?

My computer had an update for Java, I finally got around to updating it today.When updating Spysweeper poped up and said a BHO wants to run. Accept only if you trust it. Its Java so I trust it and I accepted it. Will this cause me any harm? I am asking this because I know some BHO's can be harmful. I had no problems afterward,except windows stopped responding,but it is ok after restarting.