struts2莫名奇妙的问题

java.lang.reflect.InvocationTargetException
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
java.lang.reflect.Method.invoke(Method.java:585)
com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:434)
com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:273)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:235) com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:141)
。部分省略com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:176)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:230)
com.opensymphony.xwork2.DefaultActionInvocation$1.doProfiling(DefaultActionInvocation.java:229)
com.opensymphony.xwork2.util.profiling.UtilTimerStack.profile(UtilTimerStack.java:456)
com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:227)
org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:52)
org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:477)
org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:467)
环境:
struts2:struts2-core-2.1.2.jar+xwork-2.1.1.jar+ognl-2.6.11.jar
JDK:jdk1.5.0_06
TOMCAT:tomcat-5.5.23
eclipse:用的是myeclipse 6.5.1 自带的3.3