使用maven tomcat7插件启动项目时出现错误java.lang.LinkageError

HTTP Status 500 - 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/codehaus/plexus/classworlds/realm/ClassRealm) for the method's defining class, javax/servlet/jsp/JspApplicationContext, have different Class objects for the type javax/el/ExpressionFactory used in the signature

解决方案: 刚开始使用clean tomcat7:run 启动，之后改成clean tomcat7:run-war启动就正常了。