Round a double to 3 significant figures

Question

Does anybody know how I can round a double value to 3 significant figures like the examples on this website

http://www.purplemath.com/modules/rounding2.htm

Answer 1

    public String toSignificantFiguresString(BigDecimal bd, int significantFigures ){
    String test = String.format("%."+significantFigures+"G", bd);
    if (test.contains("E+")){
        test = String.format(Locale.US, "%.0f", Double.valueOf(String.format("%."+significantFigures+"G", bd)));
    }
    return test;
}