Java Number format how to change +/- sign to custom text

Question

I would like to use number formatting for adding a text different when number is positive or negative

ex :

-3.5 => (down) 3.5

+3.5 => (up) 3.5

I have found things in DecimalFormatSymbols, but it's only possible to change minus sign and only for a single char

Is there any other simple way using number formater?

DecimalFormatSymbols unusualSymbols = new DecimalFormatSymbols(currentLocale);
unusualSymbols.setDecimalSeparator('|');
unusualSymbols.setGroupingSeparator('^');
unusualSymbols.setMinusSign();
String strange = "#,##0.###";
DecimalFormat weirdFormatter =
        new DecimalFormat(strange, unusualSymbols);
weirdFormatter.setGroupingSize(4);

String bizarre = weirdFormatter.format(12345.678);
System.out.println(bizarre);

Answer 1

You can do this in your format string for DecimalFormat:

(up) #,##0.###;(down) #,##0.###

The linked doc contains a complete syntax definition for the format string, which starts:

Pattern:
         PositivePattern
         PositivePattern ; NegativePattern

This indicates that an optional second format string separated by a semicolon (;) will be used for negative values.

Reading further:

PositivePattern:
        Prefix_opt Number Suffix_opt
NegativePattern:
        Prefix_opt Number Suffix_opt
Prefix:
        any Unicode characters except \uFFFE, \uFFFF, and special characters
Suffix:
        any Unicode characters except \uFFFE, \uFFFF, and special characters

Each pattern (positive and negative) consists of a number format string (Number) with an optional prefix and suffix string. These additional parts can be any string you like (including (up) and (down)).