Date and Number Formatting
Java programs use the DateFormat.getDateInstance(int, locale) to parse and format dates in a locale-sensitive manner. Java programs use the NumberFormat.getXXXInstance(locale) method, where XXX can be Currency, Number, or Percent, to parse and format numerical values in a locale-sensitive manner. The servlet version of Duke’s Bookstore uses the currency version of this method to format book prices.
JSTL applications use the fmt:formatDate and fmt:parseDate tags to handle localized dates and use the fmt:formatNumber and fmt:parseNumber tags to handle localized numbers, including currency values. For information on the JSTL formatting tags, see Formatting Tags. The JSTL version of Duke’s bookstore uses the fmt:formatNumber tag to format book prices and the fmt:formatDate tag to format the ship date for an order:
<fmt:formatDate value="${shipDate}" type="date" dateStyle="full"/>.
The JavaServer Faces version of Duke’s Bookstore uses date/time and number converters to format dates and numbers in a locale-sensitive manner. For example, the same shipping date is converted in the JavaServer Faces version as follows:
<h:outputText value="#{cashier.shipDate}"> <f:convertDateTime dateStyle="full"/> </h:outputText>
For information on JavaServer Faces converters, see Using the Standard Converters.