JBPM 4 与Tomcat 整合异常java.lang.LinkageError

java.lang.LinkageError:?loader?constraint?violation:?when?resolving?interface?method?"javax.servlet.jsp.JspApplicationContext.getExpressionFactory()Ljavax/el/ExpressionFactory;"?the?class?loader?(instance?of?org/apache/jasper/servlet/JasperLoader)?of?the?current?class,?
org/apache/jsp/index_jsp,?and?the?class?loader?(instance?of?org/apache/catalina/loader/StandardClassLoader)?for?resolved?class,?
javax/servlet/jsp/JspApplicationContext,?have?different?Class?objects?for?the?type?javax/el/ExpressionFactory?used?in?the?signature????JBPM4在Tomca6.0上运行的时候报出上面的异常，是EL的问题，项目中WEB-INF\lib中的三个jar包(juel.jar, juel-engine.jar, juel-impl.jar)和tomcat6下lib中jar包(el-api.jar)冲突?

解决办法如下：

一：把Tomcat6换成Tomcat5.5就ok了。

二：将juel.jar, juel-engine.jar, juel-impl.jar这三个包复制到tomcat6下lib中，

?

并删除原来的el-api.jar，把WEB-INF\lib中的juel.jar, juel-engine.jar, juel-impl.jar删除。切记要把WEB-INF\lib中的juel.jar, juel-engine.jar, juel-impl.jar删除。不然还是要冲突。