ejempo if con jstl
Agregar esto al ppio (para usar fn:length)
<%@ taglib prefix="fn" uri="http://java.sun.com/jsp/jstl/functions" %>
despues se utiliza asi (notar "gt" en vez de > )
<c:if test="${fn:length(companies) gt 0}">
<p>It is greater than 0</p>
</c:if>
si solo queremos ver si esta vacio
<c:if test="${empty companies}">
si queremos IF-ELSE
<c:choose>
<c:when test="${condition}">
//this will be executed when condition is true
</c:when>
<c:otherwise>
//this will be executed when condition is false
</c:otherwise>
</c:choose>
<c:if test="${enableDemanda != true}">class="disabled"</c:if>