页面使用el表达式报错

Question

@JFinal 你好，想跟你请教个问题：我在页面用el表达式输出内容，为什么会报这个错误呀？已经引了freemarker的jar包了。

Error executing FreeMarker template
FreeMarker template error:
The following has evaluated to null or missing:
==> document  [in template "document_list.jsp" at line 48, column 39]


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</#if>. (These only cover the last step of the expression; to cover the whole expression, use parenthessis: (myOptionVar.foo)!myDefault, (myOptionVar.foo)??


The failing instruction (FTL stack trace):
----------
==> ${document.id}  [in template "document_list.jsp" at line 48, column 37]

Answer 1

好的，解决了，谢谢波总

Answer 2

   设置一下使用 freemarker 模板：

public class MyJFinalConfig extends JFinalConfig {
 public void configConstant(Constants me) {
  me.setViewType(ViewType.FREE_MARKER);
 }
  .....
}

  其实默认就是 freemarker不需要设置，只不过你给设置成了 JSP 而已：me.setViewType(ViewType.JSP);