JSTL fmt：parseDate替代JSF

Question

How can I write:

<fmt:parseDate var="startDate" value="1/${param.month}/${param.year}"
    type="date" dateStyle="short" />

with JSF tags? As <fmt> taglib is not supported in JSF2.0. Above actually written in this way:

<jsp:include page="LeaveCalendarMonthly.jsp" flush="true">
    <jsp:param name="month" value='1' />
    <jsp:param name="year" value='2013' />
</jsp:include>

Here the month and year values are sent by parameter to the LeaveCalendarMonthly.jsp page where it uses as:

<fmt:parseDate var="startDate" value="1/${param.month}/${param.year}"
    type="date" dateStyle="short" />

The value calculates the date, and <fmt:parseDate> parses the value into date and a var 'startDate' holds the value for future use. How can I write the same thing using JSF tags?Please Help.

Answer 1

There is no JSF tag substitute for the <fmt:parseDate> .

This legacy JSTL tag converts String to Date , however when considering proper MVC design, the Date is in turn completely useless in the "view" side as the "view" is supposed to produce HTML code which only understands strings, not dates. You'd basically need to convert it back to string again. As JSF strictly follows MVC ideology, there's no such thing as <fmt:parseDate> in JSF. In fact, you should be doing this job in the model, perhaps in flavor of a custom component.

Your concrete functional requirement is not entirely clear, but so far it look much like that you need to convert a homegrown calendar thing from legacy JSP/JSTL to JSF. In that case, it's so much easier to grab an existing JSF component such as PrimeFaces <p:calendar> . This way it's a matter of

<p:calendar value="#{bean.date}" />

without the need to reinvent the whole wheel.

Answer 2

<h:outputText value="#{something that points to the date you want to convert}"><f:convertDateTime pattern="dd/MM/yyyy" /></h:outputText>