servlet 的有关问题？

servlet 的问题？？？急!!!!!!!
javax.servlet.ServletException:   org/apache/el/ExpressionFactoryImpl
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:274)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)

[解决办法]
贴代码啊.!