Use NumberFormat if you need more special approaches as to display 4.77 as 4.7, not as 4.8 (this is RoundingMode.DOWN):
NumberFormat format = NumberFormat.getInstance();
format.setRoundingMode(RoundingMode.DOWN);
format.setMaximumFractionDigits(2);
System.out.println(format.format(4.7777));
The output is 4.77