有时我会收到“内部错误”系统消息
之后我无法注销或刷新页面或注销
在我看来，有时当我将一些数据加载到表中时，我会收到此错误。
在错误日志中，我有以下内容：
java.lang.NullPointerException
at com.vaadin.data.util.IndexedContainer$IndexedContainerProperty.getValue(IndexedContainer.java:901) ~[vaadin-server-7.4.7.jar:7.4.7]
at com.vaadin.data.util.PropertyFormatter.getValue(PropertyFormatter.java:162) ~[vaadin-server-7.4.7.jar:7.4.7]
at com.vaadin.data.util.PropertyFormatter.getValue(PropertyFormatter.java:53) ~[vaadin-server-7.4.7.jar:7.4.7]
at com.vaadin.ui.AbstractField.getDataSourceValue(AbstractField.java:305) ~[vaadin-server-7.4.7.jar:7.4.7]
at com.vaadin.ui.AbstractField.getFieldValue(AbstractField.java:322) ~[vaadin-server-7.4.7.jar:7.4.7]
at com.vaadin.ui.AbstractField.validate(AbstractField.java:934) ~[vaadin-server-7.4.7.jar:7.4.7]
at com.vaadin.ui.AbstractField.getErrorMessage(AbstractField.java:1043) ~[vaadin-server-7.4.7.jar:7.4.7]
at com.vaadin.ui.AbstractComponent.beforeClientResponse(AbstractComponent.java:721) ~[vaadin-server-7.4.7.jar:7.4.7]
at com.vaadin.ui.AbstractField.beforeClientResponse(AbstractField.java:1706) ~[vaadin-server-7.4.7.jar:7.4.7]
at com.vaadin.ui.AbstractTextField.beforeClientResponse(AbstractTextField.java:111) ~[vaadin-server-7.4.7.jar:7.4.7]
at com.vaadin.server.communication.UidlWriter.write(UidlWriter.java:98) ~[vaadin-server-7.4.7.jar:7.4.7]
at com.vaadin.server.communication.UidlRequestHandler.writeUidl(UidlRequestHandler.java:149) ~[vaadin-server-7.4.7.jar:7.4.7]
at com.vaadin.server.communication.UidlRequestHandler.synchronizedHandleRequest(UidlRequestHandler.java:98) ~[vaadin-server-7.4.7.jar:7.4.7]
at com.vaadin.server.SynchronizedRequestHandler.handleRequest(SynchronizedRequestHandler.java:41) ~[vaadin-server-7.4.7.jar:7.4.7]
at com.vaadin.server.VaadinService.handleRequest(VaadinService.java:1408) [vaadin-server-7.4.7.jar:7.4.7]
at com.vaadin.server.VaadinServlet.service(VaadinServlet.java:350) [vaadin-server-7.4.7.jar:7.4.7]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:731) [servlet-api.jar:?]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303) [catalina.jar:7.0.62]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.62]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) [tomcat7-websocket.jar:7.0.62]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.62]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.62]
at org.springframework.security.web.savedrequest.RequestCacheAwareFilter.doFilter(RequestCacheAwareFilter.java:45) [spring-security-web-3.2.7.RELEASE.jar:3.2.7.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.62]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.62]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:77) [spring-web-4.1.6.RELEASE.jar:4.1.6.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.1.6.RELEASE.jar:4.1.6.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.62]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.62]
at org.vaadin.spring.http.HttpResponseFilter.doFilter(HttpResponseFilter.java:52) [spring-vaadin-0.0.5.RELEASE.jar:?]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.62]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.62]
at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:186) [spring-security-web-3.2.7.RELEASE.jar:3.2.7.RELEASE]
at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:160) [spring-security-web-3.2.7.RELEASE.jar:3.2.7.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.62]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.62]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:85) [spring-web-4.1.6.RELEASE.jar:4.1.6.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.1.6.RELEASE.jar:4.1.6.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.62]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.62]
at org.springframework.boot.context.web.ErrorPageFilter.doFilter(ErrorPageFilter.java:113) [spring-boot-1.2.3.RELEASE.jar:1.2.3.RELEASE]
at org.springframework.boot.context.web.ErrorPageFilter.access$000(ErrorPageFilter.java:59) [spring-boot-1.2.3.RELEASE.jar:1.2.3.RELEASE]
at org.springframework.boot.context.web.ErrorPageFilter$1.doFilterInternal(ErrorPageFilter.java:88) [spring-boot-1.2.3.RELEASE.jar:1.2.3.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.1.6.RELEASE.jar:4.1.6.RELEASE]
at org.springframework.boot.context.web.ErrorPageFilter.doFilter(ErrorPageFilter.java:106) [spring-boot-1.2.3.RELEASE.jar:1.2.3.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.62]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.62]
at org.apache.logging.log4j.web.Log4jServletFilter.doFilter(Log4jServletFilter.java:71) [log4j-web-2.1.jar:2.1]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241) [catalina.jar:7.0.62]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208) [catalina.jar:7.0.62]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:220) [catalina.jar:7.0.62]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:122) [catalina.jar:7.0.62]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:505) [catalina.jar:7.0.62]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:170) [catalina.jar:7.0.62]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103) [catalina.jar:7.0.62]
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:957) [catalina.jar:7.0.62]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116) [catalina.jar:7.0.62]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:423) [catalina.jar:7.0.62]
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1079) [tomcat-coyote.jar:7.0.62]
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:620) [tomcat-coyote.jar:7.0.62]
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318) [tomcat-coyote.jar:7.0.62]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_45]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_45]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-coyote.jar:7.0.62]
at java.lang.Thread.run(Thread.java:745) [?:1.8.0_45]
[2015-10-06 01:39:25][http-bio-7070-exec-7]