struts2上传得不到页面值

08:48:09.850 [http-bio-81-exec-7] DEBUG c.o.xwork2.DefaultActionInvocation - Executing action method = upload
08:48:19.824 [http-bio-81-exec-7] ERROR o.a.struts2.dispatcher.Dispatcher - Exception occurred during processing request: null
java.lang.NullPointerException: null
    at java.io.File.<init>(File.java:277) ~[na:1.8.0_20]
    at com.pop.cores.security.action.GroupCtrlAction.upload(GroupCtrlAction.java:101) ~[pop-cores-security-2.0.0-SNAPSHOT.jar:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_20]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_20]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_20]
    at java.lang.reflect.Method.invoke(Method.java:483) ~[na:1.8.0_20]
    at com.opensymphony.xwork2.DefaultActionInvocation.invokeAction(DefaultActionInvocation.java:450) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invokeActionOnly(DefaultActionInvocation.java:289) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:252) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:325) ~[struts2-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at org.apache.struts2.interceptor.DeprecationInterceptor.intercept(DeprecationInterceptor.java:41) ~[struts2-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at org.apache.struts2.interceptor.debugging.DebuggingInterceptor.intercept(DebuggingInterceptor.java:256) ~[struts2-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.DefaultWorkflowInterceptor.doIntercept(DefaultWorkflowInterceptor.java:167) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.validator.ValidationInterceptor.doIntercept(ValidationInterceptor.java:265) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at org.apache.struts2.interceptor.validation.AnnotationValidationInterceptor.doIntercept(AnnotationValidationInterceptor.java:68) ~[struts2-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.ConversionErrorInterceptor.intercept(ConversionErrorInterceptor.java:138) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:249) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:249) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.StaticParametersInterceptor.intercept(StaticParametersInterceptor.java:191) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at org.apache.struts2.interceptor.MultiselectInterceptor.intercept(MultiselectInterceptor.java:73) ~[struts2-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at org.apache.struts2.interceptor.CheckboxInterceptor.intercept(CheckboxInterceptor.java:91) ~[struts2-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at org.apache.struts2.interceptor.FileUploadInterceptor.intercept(FileUploadInterceptor.java:325) ~[struts2-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.ModelDrivenInterceptor.intercept(ModelDrivenInterceptor.java:100) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.ScopedModelDrivenInterceptor.intercept(ScopedModelDrivenInterceptor.java:141) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.ChainingInterceptor.intercept(ChainingInterceptor.java:145) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.PrepareInterceptor.doIntercept(PrepareInterceptor.java:171) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.I18nInterceptor.intercept(I18nInterceptor.java:139) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at org.apache.struts2.interceptor.ServletConfigInterceptor.intercept(ServletConfigInterceptor.java:164) ~[struts2-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.AliasInterceptor.intercept(AliasInterceptor.java:193) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.ExceptionMappingInterceptor.intercept(ExceptionMappingInterceptor.java:189) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.ParametersInterceptor.doIntercept(ParametersInterceptor.java:249) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.interceptor.MethodFilterInterceptor.intercept(MethodFilterInterceptor.java:98) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at com.pop.cores.util.interceptor.RequestInterceptor.intercept(RequestInterceptor.java:55) ~[pop-cores-util-2.0.0-SNAPSHOT.jar:na]
    at com.opensymphony.xwork2.DefaultActionInvocation.invoke(DefaultActionInvocation.java:246) ~[xwork-core-2.3.16.1.jar:2.3.16.1]
    at org.apache.struts2.impl.StrutsActionProxy.execute(StrutsActionProxy.java:54) ~[struts2-core-2.3.16.1.jar:2.3.16.1]
    at org.apache.struts2.dispatcher.Dispatcher.serviceAction(Dispatcher.java:562) ~[struts2-core-2.3.16.1.jar:2.3.16.1]
    at org.apache.struts2.dispatcher.ng.ExecuteOperations.executeAction(ExecuteOperations.java:77) [struts2-core-2.3.16.1.jar:2.3.16.1]
    at org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:99) [struts2-core-2.3.16.1.jar:2.3.16.1]
    at com.pop.cores.util.fitle.PrepareAndExecuteFilter.doFilter(PrepareAndExecuteFilter.java:72) [pop-cores-util-2.0.0-SNAPSHOT.jar:na]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.56]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.56]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) [spring-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108) [spring-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.56]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.56]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:330) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.invoke(FilterSecurityInterceptor.java:118) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.access.intercept.FilterSecurityInterceptor.doFilter(FilterSecurityInterceptor.java:84) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at com.pop.cores.security.MySecurityFilter.invoke(MySecurityFilter.java:52) [pop-cores-security-2.0.0-SNAPSHOT.jar:na]
    at com.pop.cores.security.MySecurityFilter.doFilter(MySecurityFilter.java:31) [pop-cores-security-2.0.0-SNAPSHOT.jar:na]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.access.ExceptionTranslationFilter.doFilter(ExceptionTranslationFilter.java:113) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.session.SessionManagementFilter.doFilter(SessionManagementFilter.java:103) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.authentication.AnonymousAuthenticationFilter.doFilter(AnonymousAuthenticationFilter.java:113) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.authentication.rememberme.RememberMeAuthenticationFilter.doFilter(RememberMeAuthenticationFilter.java:139) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.servletapi.SecurityContextHolderAwareRequestFilter.doFilter(SecurityContextHolderAwareRequestFilter.java:154) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter.doFilter(AbstractAuthenticationProcessingFilter.java:199) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.authentication.AbstractAuthenticationProcessingFilter$$FastClassBySpringCGLIB$$510f8b9a.invoke(<generated>) [spring-core-4.0.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) [spring-core-4.0.3.RELEASE.jar:4.0.3.RELEASE]
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:711) [spring-aop-4.0.3.RELEASE.jar:4.0.3.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) [spring-aop-4.0.3.RELEASE.jar:4.0.3.RELEASE]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) [spring-aop-4.0.3.RELEASE.jar:4.0.3.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) [spring-aop-4.0.3.RELEASE.jar:4.0.3.RELEASE]
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:644) [spring-aop-4.0.3.RELEASE.jar:4.0.3.RELEASE]
    at com.pop.cores.security.service.impl.MyUsernamePasswordAuthenticationFilterServiceImpl$$EnhancerBySpringCGLIB$$9b05d589.doFilter(<generated>) [spring-core-4.0.3.RELEASE.jar:na]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.authentication.logout.LogoutFilter.doFilter(LogoutFilter.java:110) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.context.request.async.WebAsyncManagerIntegrationFilter.doFilterInternal(WebAsyncManagerIntegrationFilter.java:50) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108) [spring-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.session.ConcurrentSessionFilter.doFilter(ConcurrentSessionFilter.java:125) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.context.SecurityContextPersistenceFilter.doFilter(SecurityContextPersistenceFilter.java:87) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy$VirtualFilterChain.doFilter(FilterChainProxy.java:342) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:192) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160) [spring-security-web-3.2.3.RELEASE.jar:3.2.3.RELEASE]
    at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:344) [spring-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
    at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:261) [spring-web-4.0.3.RELEASE.jar:4.0.3.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.56]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.56]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) [catalina.jar:7.0.56]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) [catalina.jar:7.0.56]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:503) [catalina.jar:7.0.56]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170) [catalina.jar:7.0.56]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) [catalina.jar:7.0.56]
    at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:950) [catalina.jar:7.0.56]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) [catalina.jar:7.0.56]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:421) [catalina.jar:7.0.56]
    at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1070) [tomcat-coyote.jar:7.0.56]
    at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:611) [tomcat-coyote.jar:7.0.56]
    at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:314) [tomcat-coyote.jar:7.0.56]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_20]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_20]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-coyote.jar:7.0.56]
    at java.lang.Thread.run(Thread.java:745) [na:1.8.0_20]
08:48:19.826 [http-bio-81-exec-7] DEBUG o.s.s.w.c.HttpSessionSecurityContextRepository - SecurityContext is empty or contents are anonymous - context will not be stored in HttpSession.
08:48:19.826 [http-bio-81-exec-7] DEBUG o.a.s.d.ng.PrepareOperations - skipping cleanup counter=1