Getting current date in JSTL EL and doing arithmetic on it

Question

Without using scriptlets, what's the correct way for doing date arithmetic in JSP?

Here are examples what I'm trying to do:

1. Get current year (YYYY)
2. Subtract current year by one to get previous year (YYYY)

Thanks!

Buddha

Answer 1

Use <jsp:useBean> to construct new Date. Use JSTL <fmt:formatDate> to get the year out of it. Use EL to substract it.

<%@taglib prefix="fmt" uri="http://java.sun.com/jsp/jstl/fmt" %>
<jsp:useBean id="now" class="java.util.Date" />
<fmt:formatDate var="year" value="${now}" pattern="yyyy" />
<p>Current year: ${year}</p>
<p>Previous year: ${year - 1}</p>

Result:

Current year: 2011

Previous year: 2010

Note that the pattern for full year is yyyy, not YYYY.

Undervest

Thanks a lot! Worked Perfectly – Buddha

BalusC's answers are awesome for the links to the reference material – Luedtke

You might need to use .toString() for {year-1} if you are passing it to .properties file or somewhere else which might add commas(eg: 2,010) considering it a number due to the arithmetic calculation we just did. – Predikant