java.lang.NoClassDefFoundError: javax/el/ExpressionFactory

今天在myeclipse6.5开发环境中将之前写的一个web项目部署到tomcat，部署完毕后启动，报错，异常信息如下：
信息: XML validation disabled
2010-10-25 9:58:42 org.apache.catalina.core.StandardContext listenerStart
严重: Error configuring application listener of class com.sun.faces.config.ConfigureListener
java.lang.NoClassDefFoundError: javax/el/ExpressionFactory
at java.lang.Class.getDeclaredConstructors0(Native Method)
at java.lang.Class.privateGetDeclaredConstructors(Class.java:2328)
at java.lang.Class.getConstructor0(Class.java:2640)
at java.lang.Class.newInstance0(Class.java:321)
at java.lang.Class.newInstance(Class.java:303)
at org.apache.catalina.core.StandardContext.listenerStart(StandardContext.java:3712)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4211)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:759)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:739)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:524)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:904)
at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:867)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:474)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1122)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:310)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1021)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:718)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1013)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:442)
at org.apache.catalina.core.StandardService.start(StandardService.java:450)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:709)
at org.apache.catalina.startup.Catalina.start(Catalina.java:551)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:294)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:432)
2010-10-25 9:58:42 org.apache.catalina.core.StandardContext listenerStart
严重: Skipped installing application listeners due to previous error(s)
2010-10-25 9:58:42 org.apache.catalina.core.StandardContext start
严重: Error listenerStart
2010-10-25 9:58:42 org.apache.catalina.core.StandardContext start
严重: Context [/uploadFile] startup failed due to previous errors
2010-10-25 9:58:42 org.apache.coyote.http11.Http11BaseProtocol start
分析原因是导入项目时，myeclipse在该项目.classpath下添加了如下配置
<classpathentry kind="con" path="melibrary.com.genuitec.eclipse.j2eedt.core.MYECLIPSE_JAVAEE_5_CONTAINER"/>
将其删除后启动，不再报错