java.lang.ClassCastException: org.apache.jasper.el.ELContextImpl cannot be cast to org.apache.jasper.el.ELContextImpl解决方法

找到\Tomcat7\conf\context.xml路径下的context.xml文件

<Context>
    <Loader delegate="true" />

    <!-- Default set of monitored resources -->
    <WatchedResource>WEB-INF/web.xml</WatchedResource>

    <!-- Uncomment this to disable session persistence across Tomcat restarts -->
    <!--
    <Manager pathname="" />
    -->

    <!-- Uncomment this to enable Comet connection tacking (provides events
         on session expiration as well as webapp lifecycle) -->
    <!--
    <Valve className="org.apache.catalina.valves.CometConnectionManagerValve" />
    -->

</Context>

添加标红的文字，重启tomcat就好了。