java中double类型如果小数点后为零则显示整数否则保留两位小数

public static String formatDouble(double d) {
    BigDecimal bg = new BigDecimal(d).setScale(2, RoundingMode.UP);
    double num = bg.doubleValue();
    if (Math.round(num) - num == 0) {
        return String.valueOf((long) num);
    }
    return String.valueOf(num);
}