Can't use JSTL in JSP page, with project that includes juel-impl jar because of ClassCastException with ExpressionFactoryImpl - eclipse

Question

The error is:
SEVERE: Servlet.service() for servlet [jsp] in context with path [] threw exception [Unable to compile class for JSP] with root cause
java.lang.ClassCastException: de.odysseus.el.ExpressionFactoryImpl cannot be cast to javax.el.ExpressionFactory
at javax.el.ExpressionFactory.newInstance(ExpressionFactory.java:180)
at javax.el.ExpressionFactory.newInstance(ExpressionFactory.java:107)
at org.apache.jasper.compiler.PageInfo.<init>(PageInfo.java:79)
at org.apache.jasper.compiler.Compiler.generateJava(Compiler.java:110)
.....
The project is using a war overlay, in which the overlaid project has the juel-impl jar, which is necessary for its use of shindig. Any way to use jstl in the child project jsp pages?

Answer 1

Seems you have two rivaling EL APIs in your class path, tomcat's and another one from your application. Your war file must not contain an el-api.jar or juel-api.jar. Make sure to exclude those dependencies.

Answer 2

The Juel 2.1.3 jar is a combination of the following Jars juel-impl.jar, juel-spi.jar and juel-api.jar.
We had the same issue when we included juel 2.1.3 jar in the pom and deployed in tomcat 7.
The issue is resolved by removing Juel 2.1.3 from pom and by adding only juel-impl.
<dependency>
<groupId>de.odysseus.juel</groupId>
<artifactId>juel-impl</artifactId>
<version>2.2.6</version>
</dependency>
you need to also add
<dependency>
<groupId>de.odysseus.juel</groupId>
<artifactId>juel-api</artifactId>
<version>2.2.6</version>
</dependency>
The juel 2.1.3 jar contains the javax/el interfaces and are also a part of jsp-api jar.
I hope this will help.