Tomcat7出现HTTP Status 500

zaoqiden

　　今天在Tomcat7上发布了一个war，过一阵子发现localhost:8080都进不去了。在浏览器输入http://localhost:8080出现如下内容：

HTTP Status 500 - java.lang.ClassCastException: org.apache.jasper.el.ELContextImpl cannot be cast to org.apache.jasper.el.ELContextImpl

　　type Exception report
　　message java.lang.ClassCastException: org.apache.jasper.el.ELContextImpl cannot be cast to org.apache.jasper.el.ELContextImpl
　　description The server encountered an internal error that prevented it from fulfilling this request.
　　exception

org.apache.jasper.JasperException: java.lang.ClassCastException: org.apache.jasper.el.ELContextImpl cannot be cast to org.apache.jasper.el.ELContextImpl
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:549)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:470)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

　　root cause

java.lang.ClassCastException: org.apache.jasper.el.ELContextImpl cannot be cast to org.apache.jasper.el.ELContextImpl
org.apache.jasper.runtime.PageContextImpl.proprietaryEvaluate(PageContextImpl.java:1023)
org.apache.jsp.index_jsp._jspService(index_jsp.java:85)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
javax.servlet.http.HttpServlet.service(HttpServlet.java:728)

　　note The full stack trace of the root cause is available in the Apache Tomcat/7.0.42 logs.
　　心想真是奇怪了，怎么会有这种问题，于是到网上搜索了以下，看到
　　http://zhidao.baidu.com/link?url=kF070F2GBut8OmfLq3-LVcCFUM1-qJFcTtz2xIkZ1ekshGRDx64s4hUoiRwyA29TXYwubap9pv4CoF97kP-bpK
　　里面说是EL表达式的错误，提供了两个解决方案,觉得第二个比较好使，于是修改C:\Tomcat7\conf\context.xml如下：
　　



   
   
    WEB-INF/web.xml
   
   
   
   

　　加入了上面的粗体字后，停止Tomcat7服务，在启动Tomcat7服务，还真好使了。
　　于是记之。