Difficult to be sure what you require. There is a Currency class, and up to J2SE1.4 you would have used DecimalFormat to print the result. Nowadays, you would use the formatting tags in System.out.printf for formatting; there are more details in the Formatter class API. You would use the BigDecimal class to do any arithmetic. Have a look at the Java Tutorial about formatting and currency.
You might also check out the JScience library. In addition to supporting currencies it also supports a wide variety of unit and unit conversions (it's a reference implementation of JSR-275). Check out the API for more details.