Java Decimal Format - as much precision as given

Question

I\'m working with DecimalFormat, I want to be able to read and write decimals with as much precision as given (I\'m converting to BigDecimal).

Answer 1

This seems to work fine:

public static void main(String[] args) throws Exception{
    DecimalFormat f = new DecimalFormat("0.#");
    f.setParseBigDecimal(true);
    f.setDecimalFormatSymbols(new DecimalFormatSymbols(Locale.US));// if required


    System.out.println(f.parse("1.0"));   // 1.0
    System.out.println(f.parse("1"));     // 1
    System.out.println(f.parse("1.1"));   // 1.1
    System.out.println(f.parse("1.123")); // 1.123
    System.out.println(f.parse("1."));    // 1
    System.out.println(f.parse(".01"));   // 0.01
}

Except for the last two that violate your "at least one digit" requirement. You may have to check that separately using a regex if it's really important.

Answer 2

Since you noted in a comment that you need Locale support:

Locale locale = //get this from somewhere else
DecimalFormat df = new DecimalFormat();
df.setDecimalFormatSymbols(new DecimalFormatSymbols(locale));
df.setMaximumFractionDigits(Integer.MAX_VALUE);
df.setMinimumFractionDigits(1);
df.setParseBigDecimal(true);

And then parse.