自定义Theme使用出错

[yu xu, modificado 7 Anos atrás.]

按照官网的教程https://dev.liferay.com/develop/tutorials/-/knowledge_base/7-0/themes-generator
已经新创建了一个Theme并且成功部署到服务器，能够在网页的theme选项中看到并且选用，但是选用以后出现错误：
javax.servlet.ServletException: javax.servlet.jsp.JspException: com.liferay.portal.kernel.template.TemplateException: Unable to process template my-first-theme_SERVLET_CONTEXT_/templates/portal_normal.ftl
......
com.liferay.portal.kernel.template.TemplateException: Unable to process template my-first-theme_SERVLET_CONTEXT_/templates/portal_normal.ftl
......
freemarker.core._TemplateModelException: Java method "Object.equals(Object)" takes 1 argument, but 2 was given.

----
FTL stack trace ("~" means nesting-related):
- Failed at: #if stringUtil.equals(page.getType(),... [in template "my-first-theme_SERVLET_CONTEXT_/templates/init.ftl" at line 156, column 9]
- Reached through: #include init [in template "my-first-theme_SERVLET_CONTEXT_/templates/portal_normal.ftl" at line 3, column 5]
----
freemarker.ext.beans.SimpleMethod.unwrapArguments(SimpleMethod.java:67)
freemarker.ext.beans.SimpleMethodModel.exec(SimpleMethodModel.java:72)

对应的源文件代码如下：
<#if stringUtil.equals(page.getType(),"portlet")>
<#assign is_portlet_page = true />
</#if>

这边都是按教程自动生成的，是否是缺少了依赖工具包？求大神帮忙！！！