FreeMarker template error (DEBUG mode; use RETHROW in production!): The following has evaluated to null or missing: ==> product [in template "product/detail.ftl" at line 2, column 30] ---- Tip: If the failing expression is known to 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. (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: #macro head title="" scale=1.0 [in template "common/202209/header.ftl" in macro "head" at line 1, column 1] - Reached through: @base.head title="天一文化-產品-${product.n... [in template "product/detail.ftl" at line 2, column 1] ---- Java stack trace (for programmers): ---- freemarker.core.InvalidReferenceException: [... Exception message was already printed; see it above ...] at freemarker.core.InvalidReferenceException.getInstance(InvalidReferenceException.java:134) at freemarker.core.UnexpectedTypeException.newDescriptionBuilder(UnexpectedTypeException.java:85) at freemarker.core.UnexpectedTypeException.(UnexpectedTypeException.java:48) at freemarker.core.NonHashException.(NonHashException.java:49) at freemarker.core.Dot._ at freemarker.core.Expression. at freemarker.core.DefaultToExpression._ at freemarker.core.Expression. at freemarker.core.DollarVariable.calculateInterpolatedStringOrMarkup(DollarVariable.java:100) at freemarker.core.StringLiteral._ at freemarker.core.Expression. at freemarker.core.Environment.setMacroContextLocalsFromArguments(Environment.java:1025) at freemarker.core.Environment.invokeMacroOrFunctionCommonPart(Environment.java:871) at freemarker.core.Environment.invokeMacro(Environment.java:825) at freemarker.core.UnifiedCall.accept(UnifiedCall.java:84) at freemarker.core.Environment.visit(Environment.java:347) at freemarker.core.Environment.visit(Environment.java:353) at freemarker.core.Environment.process(Environment.java:326) at freemarker.template.Template.process(Template.java:383) at org.springframework.web.servlet.view.freemarker.FreeMarkerView.processTemplate(FreeMarkerView.java:391) at org.springframework.web.servlet.view.freemarker.FreeMarkerView.doRender(FreeMarkerView.java:304) at org.springframework.web.servlet.view.freemarker.FreeMarkerView.renderMergedTemplateModel(FreeMarkerView.java:255) at org.springframework.web.servlet.view.AbstractTemplateView.renderMergedOutputModel(AbstractTemplateView.java:179) at org.springframework.web.servlet.view.AbstractView.render(AbstractView.java:316) at org.springframework.web.servlet.DispatcherServlet.render(DispatcherServlet.java:1401) at org.springframework.web.servlet.DispatcherServlet.processDispatchResult(DispatcherServlet.java:1145) at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1084) at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:963) at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1006) at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:898) at javax.servlet.http.HttpServlet.service(HttpServlet.java:634) at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:883) at javax.servlet.http.HttpServlet.service(HttpServlet.java:741) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:53) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.springframework.boot.web.servlet.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:126) at org.springframework.boot.web.servlet.support.ErrorPageFilter.access$000(ErrorPageFilter.java:64) at org.springframework.boot.web.servlet.support.ErrorPageFilter$1.doFilterInternal(ErrorPageFilter.java:101) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) at org.springframework.boot.web.servlet.support.ErrorPageFilter.doFilter(ErrorPageFilter.java:119) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201) at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:117) at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:199) at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:475) at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:80) at org.apache.catalina.valves.AbstractAccessLogValve.invoke(AbstractAccessLogValve.java:651) at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:498) at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:796) at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1374) at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) at java.base/java.lang.Thread.run(Thread.java:834)