在如下代码附近发生错误: 在模板:[template "030037255"]的[213]行[43]列, 代码:${line.pub_date?string("yyyy-MM-dd")} 附近 错误原因:The following has evaluated to null or missing: ==> line.pub_date [在模板:[template "030037255"]的[213]行[45]列] Tip: If the failing expression is known to be legally null/missing, either specify a default value with 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 parenthessis: (myOptionVar.foo)!myDefault, (myOptionVar.foo)??