FreeMarker template error (DEBUG mode; use RETHROW in production!): The following has evaluated to null or missing: ==> WebArt [in template "skin/qiyemoban/huaxinfeiyeyingwen/WebAboutUs.html" at line 21, column 26] ---- Tip: If the failing expression is known to be legally refer to something that's sometimes null or missing, either specify a default value like myOptionalVar!myDefault, or use <#if myOptionalVar??>when-present<#else>when-missing</#if>. (These only cover the last step of the expression; to cover the whole expression, use parenthesis: (myOptionalVar.foo)!myDefault, (myOptionalVar.foo)?? ---- ---- FTL stack trace ("~" means nesting-related): - Failed at: ${WebArt.artTitle!""} [in template "skin/qiyemoban/huaxinfeiyeyingwen/WebAboutUs.html" at line 21, column 24] ---- Java stack trace (for programmers): ---- freemarker.core.InvalidReferenceException: [... Exception message was already printed; see it above ...] at freemarker.core.InvalidReferenceException.getInstance(InvalidReferenceException.java:131) at freemarker.core.UnexpectedTypeException.newDesciptionBuilder(UnexpectedTypeException.java:77) at freemarker.core.UnexpectedTypeException.<init>(UnexpectedTypeException.java:40) at freemarker.core.NonHashException.<init>(NonHashException.java:46) at freemarker.core.Dot._eval(Dot.java:45) at freemarker.core.Expression.eval(Expression.java:78) at freemarker.core.DefaultToExpression._eval(DefaultToExpression.java:80) at freemarker.core.Expression.eval(Expression.java:78) at freemarker.core.Expression.evalAndCoerceToString(Expression.java:82) at freemarker.core.DollarVariable.accept(DollarVariable.java:41) at freemarker.core.Environment.visit(Environment.java:324) at freemarker.core.MixedContent.accept(MixedContent.java:54) at freemarker.core.Environment.visit(Environment.java:324) at freemarker.core.Environment.process(Environment.java:302) at freemarker.template.Template.process(Template.java:325) at org.springframework.web.servlet.view.freemarker.FreeMarkerView.processTemplate(FreeMarkerView.java:366) at org.springframework.web.servlet.view.freemarker.FreeMarkerView.doRender(FreeMarkerView.java:283) at org.springframework.web.servlet.view.freemarker.FreeMarkerView.renderMergedTemplateModel(FreeMarkerView.java:233) at org.springframework.web.servlet.view.AbstractTemplateView.renderMergedOutputModel(AbstractTemplateView.java:167) at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:267) at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1225) at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1012) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:959) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852) at javax.servlet.http.HttpServlet.service(HttpServlet.java:655) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837) at javax.servlet.http.HttpServlet.service(HttpServlet.java:764) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:227) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.eclipse.jetty.servlets.CrossOriginFilter.handle(CrossOriginFilter.java:247) at org.eclipse.jetty.servlets.CrossOriginFilter.doFilter(CrossOriginFilter.java:210) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:88) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:108) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:189) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:162) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:197) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:97) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:541) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:135) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:92) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:78) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:360) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:399) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:65) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:890) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1789) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191) at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.lang.Thread.run(Unknown Source)