关于struts2下input实现上传jsp页面报错，在线等大神帮我

Question

关于struts2下input实现上传，上传MP3，视频和jpg格式的文件导致的jsp页面报错，
红色圈出的位置报错，而上传text，文档png格式的文件ok，目前就测了这么多，
一下是产生的错误：
tag 'select', field 'list', name 'preplan.preplanType': The requested list key 'preplanTypeList' could not be resolved as a collection/array/map/enumeration/iterator type. Example: people or people.{name} - [unknown location]
at org.apache.struts2.components.Component.fieldError(Component.java:263)
at org.apache.struts2.components.Component.findValue(Component.java:356)
at org.apache.struts2.components.ListUIBean.evaluateExtraParams(ListUIBean.java:82)
at org.apache.struts2.components.Select.evaluateExtraParams(Select.java:105)
at org.apache.struts2.components.UIBean.evaluateParams(UIBean.java:893)
at org.apache.struts2.components.UIBean.end(UIBean.java:535)
at org.apache.struts2.views.jsp.ComponentTagSupport.doEndTag(ComponentTagSupport.java:42)
at org.apache.jsp.tse.emerpreplan.add_005femer_005fpreplan_jsp._jspx_meth_s_005fselect_005f0(add_005femer_005fpreplan_jsp.java:405)
at org.apache.jsp.tse.emerpreplan.add_005femer_005fpreplan_jsp._jspx_meth_s_005fform_005f0(add_005femer_005fpreplan_jsp.java:235)
at org.apache.jsp.tse.emerpreplan.add_005femer_005fpreplan_jsp._jspService(add_005femer_005fpreplan_jsp.java:101)
at org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
at org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
at org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:728)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.ApplicationDispatcher.invoke(ApplicationDispatcher.java:749)
at org.apache.catalina.core.ApplicationDispatcher.doInclude(ApplicationDispatcher.java:605)
at org.apache.catalina.core.ApplicationDispatcher.include(ApplicationDispatcher.java:544)
at org.apache.jasper.runtime.JspRuntimeLibrary.include(JspRuntimeLibrary.java:954)
at org.apache.jasper.runtime.PageContextImpl.doInclude(PageContextImpl.java:684)

Answer 1

name 'preplan.preplanType' preplan 这个你从哪里来的？