EL expressions not evaluated in JSP

Question

There\'s a small problem with my servlets/jsp web application. I\'m trying to use jstl in jsp page. When I use any tag for example:

Answer 1

Setting <%@ page isELIgnored="false" %> at the top of the page helped to me. Don't know why it was the root of the problem in my case. Not clear why yet.

Answer 2

My JSP page also couldn't recognize the <c:choose></:choose>. Always executed the false condition i.e <c:otherwise>. This is what was happening.

This was an inner JSP page i.e

<jsp:include page="your-inner-page.jsp"/>

The inner JSP was loading first and did not have the below tag libraries. They were placed on the outer JSP. Adding them to the inner worked for me.

<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<%@ taglib uri="http://www.springframework.org/tags" prefix="spring" %>
<%@ taglib uri="http://java.sun.com/jsp/jstl/functions" prefix="fn" %>
<%@ taglib uri="http://www.springframework.org/tags/form" prefix="form" %>

Answer 3

In my case for web.xml file (version="3.0") I had to run the application on Tomcat server v.8 instead of v.7, otherwise I had the same issue as you. Hope this helps someone...

<?xml version="1.0" encoding="ISO-8859-1" ?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee 
          http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    version="3.0">

Answer 4

Yes, i have doctype in web.xml <!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN" "java.sun.com/dtd/web-app_2_3.dtd"; >

Remove that <!DOCTYPE> from web.xml and make sure that the <web-app> is declared conform Servlet 2.4 or newer and all should be well. A valid Servlet 3.0 (Tomcat 7, JBoss AS 6/7, GlassFish 3, etc) compatible web.xml look like below in its entirety, without any <!DOCTYPE>:

<?xml version="1.0" encoding="UTF-8"?>
<web-app 
    xmlns="http://java.sun.com/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
    version="3.0">

    <!-- Config here. -->

</web-app>

For Servlet 3.1 (Tomcat 8, WildFly 8/9/10/11, GlassFish/Payara 4, etc) it look like below:

<?xml version="1.0" encoding="UTF-8"?>
<web-app 
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd"
    version="3.1">

    <!-- Config here. -->

</web-app>

For Servlet 4.0 (Tomcat 9, WildFly 12, GlassFish/Payara 5, etc) it look like below:

<?xml version="1.0" encoding="UTF-8"?>
<web-app 
    xmlns="http://xmlns.jcp.org/xml/ns/javaee"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
    version="4.0">

    <!-- Config here. -->

</web-app>

When using JSTL 1.1 or newer, you need to assure that your web.xml is declared in such way that the webapp runs in at least Servlet 2.4 modus, otherwise EL expressions won't work in the webapp.

When still having a Servlet 2.3 or older <!DOCTYPE> or <web-app> in web.xml, even though you already have a Servlet 2.4 or newer XSD, then it would still be forced to run in Servlet 2.3 or older modus, causing the EL expressions to fail.

The technical reason is, EL was originally part of JSTL 1.0 and not available in Servlet 2.3 / JSP 1.2 and older. In JSTL 1.1, EL was removed from JSTL and integrated in JSP 2.0, which goes along with Servlet 2.4. So, if your web.xml is declared to run the webapp in Servlet 2.3 or older modus, then JSP would expect to find EL in JSTL library, but this would in turn fail if it's a newer JSTL version, lacking EL.

See also:

• Difference between JSP EL, JSF EL and Unified EL
• Our JSTL wiki page

Answer 5

Try placing the jdbc driver class in the WEB-INF -> lib folder and verfiy the versions of servlet and jar file used. In my case, I used mssql-jdbc-8.2.2.jar and update the same in pom.xml