Format negative amount of USD with a minus sign, not brackets (Java)

Question

How do I get NumberFormat.getCurrencyInstance() to print negative USD currency values with a minus sign?

Answer 1

It's probably best to create your own DecimalFormat if you want a specific format rather than relying on the default.

Edit: You could probably also cast the result of NumberFormat.getCurrencyInstance() to DecimalFormat and adjust it to your preferences.

Answer 2

Here is one I always end up using either in a java class or via the fmt:formatNumber jstl tag:

DecimalFormat format = new DecimalFormat("$#,##0.00;$-#,##0.00");
String formatted = format.format(15.5);

It always produces at least a $0.00 and is consistent when displayed. Also includes thousands seperators where needed. You can move the minus sign in front of the dollar sign if that is your requirement.

Answer 3

It requires a little tweaking of the DecimalFormat returned by NumberFormat.getCurrencyInstance() to do it in a locale-independent manner. Here's what I did (tested on Android):

DecimalFormat formatter = (DecimalFormat)NumberFormat.getCurrencyInstance();
String symbol = formatter.getCurrency().getSymbol();
formatter.setNegativePrefix(symbol+"-"); // or "-"+symbol if that's what you need
formatter.setNegativeSuffix("");

IIRC, Currency.getSymbol() may not return a value for all locales for all systems, but it should work for the major ones (and I think it has a reasonable fallback on its own, so you shouldn't have to do anything)