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 (page 186). 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 (page 349).