我无法理解下面给出的代码。任何人都可以建议我如何编写.ftl文件的代码。我正在关注turtorial http://www.mkyong.com/struts2/working-with-struts-2-theme-template/
<#--
Only show message if errors are available.
This will be done if ActionSupport is used.
-->
<#assign hasFieldErrors = parameters.name?? && fieldErrors??
&& fieldErrors[parameters.name]??/>
<#if hasFieldErrors>
<#list fieldErrors[parameters.name] as error>
<span class="errorMessage" errorFor="${parameters.id}">${error?html}</span><#t/>
</#list>
</#if>