Serious : Servlet.service () for servlet [jsp] in context with path [] threw exception

Serious : Servlet.service () for servlet [jsp] in context with path [] threw exception [java.lang.NoClassDefFoundError: javax / el / ELResolver ] with root cause
java.lang.ClassNotFoundException: javax.el.ELResolver
at java.net.URLClassLoader $ 1.run (URLClassLoader.java: 366)
at java.net.URLClassLoader $ 1.run (URLClassLoader.java: 355)
at java.security.AccessController.doPrivileged (Native Method)
at java.net.URLClassLoader.findClass (URLClassLoader.java: 354)
at java.lang.ClassLoader.loadClass (ClassLoader.java: 423)
at java.lang.ClassLoader.loadClass (ClassLoader.java: 356)
at java.lang.ClassLoader.defineClass1 (Native Method)
at java.lang.ClassLoader.defineClass (ClassLoader.java: 791)
at java.security.SecureClassLoader.defineClass (SecureClassLoader.java: 142)
at java.net.URLClassLoader.defineClass (URLClassLoader.java: 449)
at java.net.URLClassLoader.access $ 100 (URLClassLoader.java: 71)
at java.net.URLClassLoader $ 1.run (URLClassLoader.java: 361)
at java.net.URLClassLoader $ 1.run (URLClassLoader.java: 355)
at java.security.AccessController.doPrivileged (Native Method)
at java.net.URLClassLoader.findClass (URLClassLoader.java: 354)
at java.lang.ClassLoader.loadClass (ClassLoader.java: 423)
at java.lang.ClassLoader.loadClass (ClassLoader.java: 410)
at sun.misc.Launcher $ AppClassLoader.loadClass (Launcher.java: 308)
at java.lang.ClassLoader.loadClass (ClassLoader.java: 410)
at java.lang.ClassLoader.loadClass (ClassLoader.java: 356)
at java.lang.Class.forName0 (Native Method)
at java.lang.Class.forName (Class.java: 186)
at javax.el.CompositeELResolver. (CompositeELResolver.java: 30)
at org.apache.jasper.el.ELContextImpl. (ELContextImpl.java: 79)
at org.apache.jasper.compiler.Validator $ ValidateVisitor.prepareExpression (Validator.java: 1571)
at org.apache.jasper.compiler.Validator $ ValidateVisitor.visit (Validator.java: 747)
at org.apache.jasper.compiler.Node $ ELExpression.accept (Node.java: 954)
at org.apache.jasper.compiler.Node $ Nodes.visit (Node.java: 2376)
at org.apache.jasper.compiler.Node $ Visitor.visitBody (Node.java: 2428)
at org.apache.jasper.compiler.Node $ Visitor.visit (Node.java: 2434)
at org.apache.jasper.compiler.Node $ Root.accept (Node.java: 475)
at org.apache.jasper.compiler.Node $ Nodes.visit (Node.java: 2376)
at org.apache.jasper.compiler.Validator.validateExDirectives (Validator.java: 1798)
at org.apache.jasper.compiler.Compiler.generateJava (Compiler.java: 217)
at org.apache.jasper.compiler.Compiler.compile (Compiler.java: 373)
at org.apache.jasper.compiler.Compiler.compile (Compiler.java: 353)
at org.apache.jasper.compiler.Compiler.compile (Compiler.java: 340)
at org.apache.jasper.JspCompilationContext.compile (JspCompilationContext.java: 646)
at org.apache.jasper.servlet.JspServletWrapper.service (JspServletWrapper.java: 357)
at org.apache.jasper.servlet.JspServlet.serviceJspFile (JspServlet.java: 390)
at org.apache.jasper.servlet.JspServlet.service (JspServlet.java: 334)
at javax.servlet.http.HttpServlet.service (HttpServlet.java: 728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter (ApplicationFilterChain.java: 305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter (ApplicationFilterChain.java: 210)
at org.apache.catalina.core.StandardWrapperValve.invoke (StandardWrapperValve.java: 222)
at org.apache.catalina.core.StandardContextValve.invoke (StandardContextValve.java: 123)
at org.apache.catalina.core.StandardHostValve.invoke (StandardHostValve.java: 171)
at org.apache.catalina.valves.ErrorReportValve.invoke (ErrorReportValve.java: 99)
at org.apache.catalina.valves.AccessLogValve.invoke (AccessLogValve.java: 953)
at org.apache.catalina.core.StandardEngineValve.invoke (StandardEngineValve.java: 118)
at org.apache.catalina.connector.CoyoteAdapter.service (CoyoteAdapter.java: 408)
at org.apache.coyote.http11.AbstractHttp11Processor.process (AbstractHttp11Processor.java: 1023)
at org.apache.coyote.AbstractProtocol $ AbstractConnectionHandler.process (AbstractProtocol.java: 589)
at org.apache.tomcat.util.net.AprEndpoint $ SocketProcessor.run (AprEndpoint.java: 1852)
at java.util.concurrent.ThreadPoolExecutor.runWorker (ThreadPoolExecutor.java: 1110)
at java.util.concurrent.ThreadPoolExecutor $ Worker.run (ThreadPoolExecutor.java: 603)
at java.lang.Thread.run (Thread.java: 722)

After starting Tomcat , visit http://localhost:8080, this error will appear online Baidu many methods do not work, ask the god pointing
------ Solution ------ --------------------------------------
tomcat \ conf \ Catalina \ localhost there there is no Root.xml file , any try to delete
------ Solution -------------------------- ------------------
http://blog.csdn.net/huayu815/article/details/6680556
------ For reference only ---------------------------------------
Thank you bothering me for a long time , and finally can be used on tomcat7 the