Format floating point number with leading zeros [duplicate]

Answer 1

DecimalFormat formatter = (DecimalFormat)NumberFormat.getNumberInstance(Locale.US);
formatter.applyPattern("000.###");
System.out.format(formatter.format(1.23456789));

Result:

001.234

Demo

Answer 2

Number after %0 here defines full width including decimal point, so you need to change it to 7:

System.out.format("%07.3f", 1.23456789);