Java - How to convert string to big decimal with money format

Question

My string is "1234567" and I want to get two big decimal object like these 12345,67 and 12.345,67 but I couldn't do this. Code is shown as below:

DecimalFormat decimalFormat = new DecimalFormat("#,##0.###");
decimalFormat.setParseBigDecimal(true);
String n = decimalFormat.format(1234567);
BigDecimal bigDecimal = (BigDecimal)decimalFormat.parse(n);

DecimalFormat decimalFormat1 = new DecimalFormat("#,0#");
decimalFormat1.setParseBigDecimal(true);
String n1 = decimalFormat.format(1234567);
BigDecimal bigDecimal1 = (BigDecimal)decimalFormat.parse(n1);

System.out.println(n);
System.out.println(bigDecimal);
System.out.println(n1);
System.out.println(bigDecimal1);

Output:

1.234.567,00
1234567.00
1.234.567,00
1234567.00

Expected output:

12.345,67 12.345,67
12345,67
12345,67

Thank you for your help

Answer 1

Number formatting is always locale specific. Therefore a defined locale is needed. Following approach will work for the formatting:

    BigDecimal money = new BigDecimal("1234567");

    DecimalFormatSymbols symbols = new DecimalFormatSymbols(Locale.GERMAN);
    symbols.setDecimalSeparator(',');
    symbols.setGroupingSeparator('.');

    // https://docs.oracle.com/javase/8/docs/api/java/text/DecimalFormat.html
    DecimalFormat format = new DecimalFormat("###,###.00");
    format.setDecimalFormatSymbols(symbols);

    System.out.println(format.format(money));

However, this does not meet the requirement to parse any given number as a decimal with 2 digits. Here, I would personally would apply a division by 100 or, insert a decimal separator into the given String.

    BigDecimal money = new BigDecimal("1234567").divide(new BigDecimal("100"));

Inserting a defined decimal separator could work like this:

    private static String prepare(String input) {
        if (input.length() == 2) {
            return ","+input;
        } 
        if (input.length() == 1) {
            return ",0"+input;
        }
        String integerPart = input.substring(0, input.length()-2);
        String fraction = input.substring(input.length()-2);
        return integerPart+","+fraction;
    }

Using the new DecimalFormat and the prepare() method it would work to parse a String as a number with 2 decimals by default.

    String input = "1234567";
    String prepared = prepare(input);

    DecimalFormatSymbols symbols = new DecimalFormatSymbols(Locale.GERMAN);
    symbols.setDecimalSeparator(',');
    symbols.setGroupingSeparator('.');

    DecimalFormat format = new DecimalFormat("###,###.00");
    format.setDecimalFormatSymbols(symbols);
    format.setParseBigDecimal(true);

    BigDecimal bigDecimal = (BigDecimal)format.parse(prepared);
    String n = format.format(bigDecimal);

    System.out.println(n);