首页> FreeMarker template error (DEBUG mode; use RETHROW in production!): The following has evaluated to null or missing: ==> parentCategoryList[parentCategoryList?size - 1] [in template "myTemplate" at line 28, column 59] ---- Tip: It's the final [] step that caused this error, not those before it. ---- 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: ${parentCategoryList[parentCategoryLi... [in template "myTemplate" at line 28, column 57] ---- Java stack trace (for programmers): ---- freemarker.core.InvalidReferenceException: [... Exception message was already printed; see it above ...] at freemarker.core.InvalidReferenceException.getInstance(InvalidReferenceException.java:134) at freemarker.core.UnexpectedTypeException.newDescriptionBuilder(UnexpectedTypeException.java:85) at freemarker.core.UnexpectedTypeException.(UnexpectedTypeException.java:48) at freemarker.core.NonHashException.(NonHashException.java:49) at freemarker.core.Dot._eval(Dot.java:48) at freemarker.core.Expression.eval(Expression.java:101) at freemarker.core.DollarVariable.calculateInterpolatedStringOrMarkup(DollarVariable.java:100) at freemarker.core.DollarVariable.accept(DollarVariable.java:63) at freemarker.core.Environment.visit(Environment.java:347) at freemarker.core.Environment.visit(Environment.java:353) at freemarker.core.Environment.process(Environment.java:326) at freemarker.template.Template.process(Template.java:383) at com.joyhua.common.util.FreeMakerUtil.createTemplateByString(FreeMakerUtil.java:81) at com.joyhua.ews.data.service.impl.EwsWebsiteCategoryImpl.createListPage(EwsWebsiteCategoryImpl.java:3134) at com.joyhua.ews.data.service.impl.EwsWebsiteCategoryImpl.createCategoryById(EwsWebsiteCategoryImpl.java:2853) at com.joyhua.ews.task.CreateAllCategoryListTask.execute(CreateAllCategoryListTask.java:38) at com.joyhua.ews.task.ScheduledOfTask.run(ScheduledOfTask.java:30) at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) at org.springframework.scheduling.concurrent.ReschedulingRunnable.run(ReschedulingRunnable.java:95) at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:515) at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264) at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:304) at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1128) at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:628) at java.base/java.lang.Thread.run(Thread.java:834)