java web在进行管理员操作的时候，抛出了下面的异常，怎么解决啊

HTTP Status 500 - An exception occurred processing JSP page /Admin/adminMember.jsp at line 40 type Exception report message An exception occurred processing JSP page /Admin/adminMember.jsp at line 40 description The server encountered an internal error that prevented it from fulfilling this request. exception org.apache.jasper.JasperException: An exception occurred processing JSP page /Admin/adminMember.jsp at line 40 37: </tr> 38: <tr> 39: <td height="30" align="center"> 40: <display:table name="memberList" id="row" pagesize="15" export="true" class="displaytag" requestURI="/Admin/adminMember.do?method=browseMember" > 41: <display:column property="loginName" title="${label1}" sortable="true" headerClass="sortable" style="text-align:center;"/> 42: <display:column property="memberName" title="${label2}" style="text-align:center;"/> 43: <display:column property="memberlevel.levelName" title="${label3}" sortable="true" headerClass="sortable" style="text-align:center;"/> Stacktrace: org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:584) org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:466) org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:385) org.apache.jasper.servlet.JspServlet.service(JspServlet.java:329) javax.servlet.http.HttpServlet.service(HttpServlet.java:729) org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) org.apache.struts.action.RequestProcessor.doForward(RequestProcessor.java:1085) org.apache.struts.action.RequestProcessor.processForwardConfig(RequestProcessor.java:398) org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:241) org.apache.struts.action.ActionServlet.process(ActionServlet.java:1196) org.apache.struts.action.ActionServlet.doGet(ActionServlet.java:414) javax.servlet.http.HttpServlet.service(HttpServlet.java:622)