Decimal separator is set to "|"

import java.text.DecimalFormat;
import java.text.DecimalFormatSymbols;

public class Main {
  public static void main(String args[]) {
    double d = 123456.7890;
    DecimalFormat df = new DecimalFormat("######.##");
    DecimalFormatSymbols dfs = df.getDecimalFormatSymbols();

    dfs.setDecimalSeparator('|');
    df.setDecimalFormatSymbols(dfs);
    System.out.println(df.format(d));
  }
}

123456|79