freemarker如何获取页面请求的参数

用例描述:

A页面:http://localhost:8080/Houser/newsManage.action?categoryname=402880f5122bc83801122bd89fae0005

B页面:newsManage.ftl

在ftl页面这样写:

${request.getParameter("categoryname")}

但是假如你要用<#if 指令让${request.getParameter("categoryname")}参与比较呢？有一个小地方要注意一下：
正确写法：

1)

     <#list pagesdatas as ls> 

      <#if ls.newscategory.id?default("") = ‘${request.getParameter("categoryname")}‘>

      .....................

      </#if>  

     </#list> 

2)

<#list pagesdatas as ls> 

      <#if ls.newscategory.id?default("") = "${request.getParameter(‘categoryname‘)}">

      .....................

      </#if>  

     </#list>

3

<#list pagesdatas as ls> 

      <#if ls.newscategory.id?default("") = "${request.getParameter(\"categoryname\")}">

      .....................

      </#if>  

     </#list> 
错误写法：

     <#list pagesdatas as ls> 

      <#if ls.newscategory.id?default("") = "${request.getParameter("categoryname")}">

      .....................

      </#if>  

     </#list> 

原因:估记应该是4个双引号冲突了


补充:把${request.getParameter("categoryname")}赋值给变量的正确写法:

1)<#assign var ="${request.getParameter(‘categoryname‘)}">

2) <#assign var =‘${request.getParameter(‘categoryname‘)}‘>

3)<#assign var ="${request.getParameter(\"categoryname\")}">