Forcing BigDecimals to use scientific notation

Question

I have this method:

    public void Example(BigDecimal value, int scale){
    BigDecimal x = new BigDecimal(\"0.00001\");
    System.out.println(\"result: \"         


        

Answer 1

You can use a DecimalFormat with setMinimumFractionDigits(int scale):

private static String format(BigDecimal x, int scale) {
  NumberFormat formatter = new DecimalFormat("0.0E0");
  formatter.setRoundingMode(RoundingMode.HALF_UP);
  formatter.setMinimumFractionDigits(scale);
  return formatter.format(x);
}
...
System.out.println(format(new BigDecimal("0.00001"), 2)); // 1.00E-5
System.out.println(format(new BigDecimal("0.00001"), 3)); // 1.000E-5