Java Data Type - 如何将格式设置为两个小数位：设置最小分数位数

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));

  }
}