java - 如何将此行从 Velocity 转换为 FreeMarker？

Question

我想将此行从 Velocity 转换为 Freemarker:

#set ($valid_portlet_description = $validator.isNotNull($portlet_description) 
&& $portlet_description.indexOf('javax.portlet.description') == -1)

我尝试将代码更改为:

<#assign valid_portlet_description = validator.isNotNull(portlet_description) 
&& portlet_description?index_of("javax.portlet.description") == "-1" />

但是我收到以下错误:

freemarker.template.TemplateException: The only legal comparisons are between two numbers, two strings, or two dates. Left hand operand is a freemarker.template.SimpleNumber Right hand operand is a freemarker.template.SimpleScalar

Answer 1

该消息提示此声明:

portlet_description?index_of("javax.portlet.description") == "-1"

它表示您有不同的类型:数字在左侧，但 SimpleScalar (在 Freemarker 术语中只是 String)在右侧。要解决此问题，您只需删除引号即可:

portlet_description?index_of("javax.portlet.description") == -1