Define tag cannot set a null value 这是错误！

type Exception reportmessage description The server encountered an internal error () that prevented it from fulfilling this request.exception javax.servlet.ServletException: Define tag cannot set a null value
org.apache.jasper.runtime.PageContextImpl.doHandlePageException(PageContextImpl.java:825)
org.apache.jasper.runtime.PageContextImpl.handlePageException(PageContextImpl.java:758)
org.apache.jsp.zcgl.guizhangzhidudictionary_jsp._jspService(guizhangzhidudictionary_jsp.java:365)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1033)
org.apache.struts.tiles.TilesRequestProcessor.doForward(TilesRequestProcessor.java:269)
org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:436)
org.apache.struts.tiles.TilesRequestProcessor.processForwardConfig(TilesRequestProcessor.java:312)
org.apache.struts.action.RequestProcessor.processActionForward(RequestProcessor.java:401)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:279)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1422)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:523)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:123)
com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:66)
com.opensource.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:178)
root cause javax.servlet.jsp.JspException: Define tag cannot set a null value
org.apache.struts.taglib.bean.DefineTag.doEndTag(DefineTag.java:272)
org.apache.jsp.zcgl.guizhangzhidudictionary_jsp._jspService(guizhangzhidudictionary_jsp.java:91)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:94)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:324)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:292)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:236)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1033)
org.apache.struts.tiles.TilesRequestProcessor.doForward(TilesRequestProcessor.java:269)
org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:436)
org.apache.struts.tiles.TilesRequestProcessor.processForwardConfig(TilesRequestProcessor.java:312)
org.apache.struts.action.RequestProcessor.processActionForward(RequestProcessor.java:401)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:279)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1422)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:523)
javax.servlet.http.HttpServlet.service(HttpServlet.java:709)
javax.servlet.http.HttpServlet.service(HttpServlet.java:802)
com.opensymphony.module.sitemesh.filter.PageFilter.parsePage(PageFilter.java:123)
com.opensymphony.module.sitemesh.filter.PageFilter.doFilter(PageFilter.java:66)
com.opensource.filters.SetCharacterEncodingFilter.doFilter(SetCharacterEncodingFilter.java:178)
note The full stack trace of the root cause is available in the Apache Tomcat/5.0.28 logs.
--------------------------------------------------------------------------------Apache Tomcat/5.0.28