Fraction Digits Minimum

import java.text.NumberFormat;

public class Main {
  public static void main(String[] argv) throws Exception {

    NumberFormat nf = NumberFormat.getInstance();

    nf.setMinimumFractionDigits(2);

    System.out.println("Format with two decimal places: " + nf.format(1234567.678));
    System.out.println("Format with two decimal places: " + nf.format(1234567.6));
  }
}

Format with two decimal places: 1,234,567.678
Format with two decimal places: 1,234,567.60