According to TLD or attribute directive in tag file, attribute test does not accept any expressions
2.4及以后写成(JSTL1.1)
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>
2.3及以前(JSTL1.0)
<%@taglib prefix="c" uri="http://java.sun.com/jstl/core" %>