Issues with evaluation of EL expressions

Question

Hey everyone
I am having issues with EL expressions being printed instead of evaluated when they are between tags. They work fine when they are in the tag itself. I will show you my code:
This is a snippet from the parent file that includes the other file:
<jsp:include page="./includes/test.jsp" >
  <jsp:param name="color" value="blue" />
</jsp:include>This is the test.jsp file. It all works as expected except for that second line which only prints ${param.color} instead of the actual parameter text:
REGULAR OUTPUT WORKS
<br><font color="red"> COLOR OUTPUT WORKS</font>
<br>${param.color}
<br>Param inside color tag: <font color='${param.color}'>HERE</font>
<% String test = request.getParameter("color"); %>
<br>OUT.PRINT input: <% out.print(test); %>This is the output:
REGULAR OUTPUT WORKS
COLOR OUTPUT WORKS (this is in red)
${param.color}
Param inside color tag: HERE (the word 'here' is in blue)
OUT.PRINT input: blue
In my book (Head First Servlets and JSP) it uses this exact syntax and says it should work. I am running tomcat 5.5. Any ideas? Thanks!
John
EDIT: I got it working with <c:out> but is there a way to do it without <c:out>?? Like I said before my book does it without <c:out> and it seems to work for them and is much cleaner looking that way.
John
Edited by: jrock on Nov 14, 2007 3:45 AM

Answer 1

is there a difference between the JAR files for 1.0 and 1.1? Or is it the same JAR and only URI changes? Yes there is a difference between the 1.0 and 1.1 JSTL jar files.
The JSTL1.1 jar files includes the JSTL1.0 tlds for backwards compatibility.
Check what version you've got by looking at the Manifest.mf in the META-INF directory of one of the jars.
You can get JSTL1.1 from here: http://jakarta.apache.org/site/downloads/downloads_taglibs-standard.cgi
Also with JSP 2.0 / JSTL 1.1 is it possible to still use web.xml entries if I want? Its possible to retain those web.xml entries, but not really recommended. The container should find it without your spelling it out.
If you do go down that path, just make sure you match the right URI to the right tld. Nothing would be more confusing than using the JSTL1.1 uri and mapping it to the JSTL1.0 tld file :-)
Also, the <taglib> tags are no longer a top level element of a webapp, but need to be nested inside a <jsp-config> in the new schema.
ie previously it was
<web-app>
  <taglib>
    <taglib-uri>/WEB-INF/struts-bean.tld</taglib-uri>
    <taglib-location>/WEB-INF/struts-bean.tld</taglib-location>
  </taglib>
...The web.xml from from version 2.3 to 2.4 is not entirely compatible.
You now need to make it
<web-app>
<jsp-config>
  <taglib>
    <taglib-uri>/WEB-INF/struts-bean.tld</taglib-uri>
    <taglib-location>/WEB-INF/struts-bean.tld</taglib-location>
  </taglib>
</jsp-config>
...