Hi All,
i wanted to use expression language (EL) in my jsp page. But the expression language code is not getting evaluated. For example
for the following code
<jsp:root version="2.0">
<jsp:declaration>String s="Test String">
<jsp:text>This is a ${s}</jsp:text>
</jsp:root>
The output is "This is a ${s}". The EL ${s} is not being evaluated.

I am using Tomcat 4.1.24, which implements JSP 1.2 spec.
In JSP 1.2 specification i found that EL can be enabled by adding the following code under the element <web-app> in the web.xml file
<jsp-config>
<jsp-property-group>
<url-pattern>*.jsp</url-pattern>
<el-ignored>true</el-ignored>
</jsp-property-group>
<jsp-config>

but on adding this code in web.xml file tomcat generates parse error stating that "<jsp-config>" element not found. Now the problem is the dtd file (web-app_2_3.dtd) which is refered by web.xml is not having the element <jsp-config> or <jsp-property-group> or <el-enabled>

IF SOMEONE HAVE FOUND SOME SOLUTION FOR THIS KIND OF PROBLEM PLS HELP ME

Thanx,
Karthikraj.

 

 

I am having the same problem...



your la tag should be </jsp-config> i believe
im going to give this a try...

 

 

I had the same problem using the <jsp-config> tag. When I inserted the tag in the web.xml. It not only caused validation errors against http://java.sun.com/dtd/web-app_2_3.dtd but it caused errors in my web site which uses Struts 1.1.

Solution

Use the Page Directive isELIgnored and set it to false
<%@ page isELIgnored="false" %>
instead of using the <jsp-config> tag in the web.xml

Reference
JavaServer Pages 2.0 Specification page I-88
Table JSP.3-1
http://jcp.org/aboutJava/communityprocess/final/jsr152/

 

 

The EL is only added to the page in general as part of the JSP2.0 spec. Currently that means Tomcat 5.
For JSP1.2 containers use JSTL 1.0 For JSP2.0 containers use JSTL 1.1

In order to use the EL statements in JSP1.2 containers, you need to use it as an attribute of a c:out tag. The JSTL tag provides the EL translation engine. That is why JSTL1.0 provides both standard and RT versions, so you can decide whether to use EL or scriptlet expressions in your pages.

In JSP2.0 the EL translation is incorporated into the tomcat engine, and so it can be used straight on a page

In short you need to do something like this:
<c:set var="s" value="S"/>
<c:out value="${s}"/>

Note also that variables declared in your code like "String s" are not visible to the EL.
The EL variable space is the attribute space: pageContext, requestContext, sessionContext and applicationContext. So you need to set an attribute in one of these contexts in order for EL to find it.
Doing a jsp:useBean tag declares a bean both as a java variable and am attribute, so it can be used in both scriptlet and EL code.

Good luck,
evnafets

 

 

Nope thats the JSP2.0 spec that you are reading.
And that only applies if the version of your web.xml file is not 2.4. If the declaration at the top of your xml file specifies as version 2.3, then for backwards compatibility it disables EL evaluation, unless you include that page directive explicitly on a page. If web.xml is up to date, then EL will be processed as normal.

Regardless, this only applies to JSP2.0 containers - Tomcat 5 - and not less.

 

 

Make sure that you actually specify the version= for tomcat.

I just inserted an empty <web-app> tag in order to add some tag libs, expecting Tomcat to default to its conf/web.xml. Not so.

This was in amongst some other changes and cost me several hours of stuffing about. Bergsten does not mention that you have to enable JSTL!

Anthony

 

 

<jsp:root version="1.2" xmlns:jsp="http://java.sun.com/JSP/Page" xmlns:display="urn:jsptld:http://displaytag.sf.net/el" xmlns:c="urn:jsptld:http://java.sun.com/jstl/core">
<jsp:directive.page contentType="text/html; charset=UTF-8" isELIgnored="false"/>

For the above if i add isELIgnored="false" am getting following..
could no process the requestorg.apache.jasper.JasperException: /web/viewdata.jsp(16,40) According to TLD or attribute directive in tag file, attribute items does not accept any expressions

 

 

You have a conflict in your page.

You are specifying JSP version1.2 in the <jsp:root> tag
You are then using a directive which only applies to JSP2.0 (isELIgnored)

So which is it? Are you writing for JSP1.2 or JSP2.0?
If for JSP1.2, then declare your web.xml as being DTD 2.3, and leave out that directive.

If you are using JSP2.0, then use the appropriate taglibs - JSTL1.1, and the standard displaytag - not the "el" version.

Hope this helps,
evnafets

 

 

I have a similar problem with EL, but I think it has to do with versions.
I am using JDK version 1.4.0_03 and Tomcat version 5.5.

Its my tag files that contain EL to show the attribute values passed to them. However, I have tried alternate JSTL tags such as suggested above, but it still does not work. I also tried modifying the web.xml file in the /conf directory as suggested above.

As these are tag files, I can't use the page directive anyways. But what confuses me most is that even the JSTL doesn't seem to execute. So I am supposing versions has something to do with it.

I have tried all this on JDK verison 1.5.0_06 and Tomcat 6 where it works perfectly, but I need to do this on 1.4 also. Any help will be appreciated.

 

 

Check your web.xml file to make sure it is up to date.
For info on setting up JSTL see this post, reply#6: http://forum.java.sun.com/thread.jspa?threadID=629437&tstart=0

Tomcat5.5 was written with Java1.5 in mind.
To use Java1.4 with Tomcat5.5 you have to have a compatibility package.
Did you download and install that? (http://tomcat.apache.org/download-55.cgi#5.5.23)

 

 

Thanks, it worked! I read another thread that helped:
http://forum.java.sun.com/thread.jspa?forumID=45&threadID=588217

Here's the documentation of what I did:

1. I updated JDK to 1.5.0_06
2. I updated the header in my web application's "web.xml" file:

<web-app xmlns="http://java.sun.com/xml/ns/j2ee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd" version="2.4">

(Surprisingly, I formerly had version set as 2.5 and it wasn't working, but with 2.4 it works)

3. I restarted Tomcat and reloaded my application

 

 

Thats because Tomcat5.5 only supports ServletSpec 2.4
To run with 2.5 you need Tomcat 6 at least.