JBPM与SSH整合，部署异常

今天开始正式接触JBPM工作流，部署了JBPM4.4的一个小例子，部署好访问时出现以下异常：

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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

在网上搜了下资料，原来是与tomcat版本有关。我用的是tomcat6，用5.5则没问题。

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用tomcat6的解决方法：

把以下三个包juel.jar ?juel-engine.jar ?juel-impl.jar拷贝到tomcat的lib下，并且删除项目中的这三个包。然后把tomcat的lib下el-api.jar包删除。搞定。