struts2.0.14-doubleselect 用来作级联 官方demo

官方demo

  <s:form name="form0">
 
 
 <s:doubleselect label="doubleselect test1" name="menu" list="{'fruit','other'}" doubleName="dishes" doubleList="top == 'fruit' ? {'apple', 'orange'} : {'monkey', 'chicken'}" />

</s:form>

 

用来作级联

 

 

如果 form 中没有指定 name,doubleselect 中formName没有指定成form的name值，就可能出现

FreeMarker template error!

Expression parameters.formName is undefined on line 98, column 43 in template/simple/doubleselect.ftl.
The problematic instruction:
----------
==> ${parameters.formName} [on line 98, column 41 in template/simple/doubleselect.ftl]
 in include "/${parameters.templateDir}/simple/doubleselect.ftl" [on line 25, column 1 in template/xhtml/doubleselect.ftl]
----------

Java backtrace for programmers:
----------
freemarker.core.InvalidReferenceException: Expression parameters.formName is undefined on line 98, column 43 in template/simple/doubleselect.ftl.
	at freemarker.core.TemplateObject.assertNonNull(TemplateObject.java:124)
	at freemarker.core.Expression.getStringValue(Expression.java:118)
	at freemarker.core.Expression.getStringValue(Expression.java:93)
	at freemarker.core.DollarVariable.accept(DollarVariable.java:76)
	at freemarker.core.Environment.visit(Environment.java:196)
	at freemarker.core.MixedContent.accept(MixedContent.java:92)
	at freemarker.core.Environment.visit(Environment.java:196)
	at freemarker.core.Environment.include(Environment.java:1375)
	at freemarker.core.Include.accept(Include.java:155)
	at freemarker.core.Environment.visit(Environment.java:196)
	at freemarker.core.MixedContent.accept(MixedContent.java:92)
	at freemarker.core.Environment.visit(Environment.java:196)
	at freemarker.core.Environment.process(Environment.java:176)
	at freemarker.template.Template.process(Template.java:232)
	at org.apache.struts2.components.template.FreemarkerTemplateEngine.renderTemplate(FreemarkerTemplateEngine.java:168)
	at org.apache.struts2.components.UIBean.mergeTemplate(UIBean.java:530)
	at org.apache.struts2.components.UIBean.end(UIBean.java:484)
	at org.apache.struts2.views.jsp.ComponentTagSupport.doEndTag(ComponentTagSupport.java:43)
	at org.apache.jsp.index_jsp._jspx_meth_s_005fdoubleselect_005f0(index_jsp.java:168)
	at org.apache.jsp.index_jsp._jspx_meth_s_005fform_005f0(index_jsp.java:128)
	at org.apache.jsp.index_jsp._jspService(index_jsp.java:89)
	at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
	at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:393)
	at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:320)
	at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:266)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:290)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.struts2.dispatcher.FilterDispatcher.doFilter(FilterDispatcher.java:416)
	at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:235)
	at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:206)
	at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:230)
	at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:175)
	at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:128)
	at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
	at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:109)
	at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:261)
	at org.apache.coyote.http11.Http11Processor.process(Http11Processor.java:844)
	at org.apache.coyote.http11.Http11Protocol$Http11ConnectionHandler.process(Http11Protocol.java:581)
	at org.apache.tomcat.util.net.JIoEndpoint$Worker.run(JIoEndpoint.java:447)
	at java.lang.Thread.run(Thread.java:662)