HTTP Status 500 - javax.servlet.ServletException: java.lang.NullPointerException

type Exception report
message javax.servlet.ServletException: java.lang.NullPointerException
description The server encountered an internal error that prevented it from fulfilling this request.
exception 
org.apache.jasper.JasperException: javax.servlet.ServletException: java.lang.NullPointerException
	org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:585)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:455)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	org.nutz.mvc.NutFilter.nextChain(NutFilter.java:230)
	org.nutz.mvc.NutFilter.doFilter(NutFilter.java:205)

root cause 
javax.servlet.ServletException: java.lang.NullPointerException
	org.apache.jsp.list_jsp._jspService(list_jsp.java:427)
	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	org.nutz.mvc.NutFilter.nextChain(NutFilter.java:230)
	org.nutz.mvc.NutFilter.doFilter(NutFilter.java:205)

root cause 
java.lang.NullPointerException
	org.apache.catalina.session.ManagerBase.generateSessionId(ManagerBase.java:805)
	org.apache.catalina.session.ManagerBase.createSession(ManagerBase.java:651)
	org.apache.catalina.connector.Request.doGetSession(Request.java:2946)
	org.apache.catalina.connector.Request.getSession(Request.java:2310)
	org.apache.catalina.connector.RequestFacade.getSession(RequestFacade.java:897)
	org.apache.catalina.connector.RequestFacade.getSession(RequestFacade.java:909)
	org.apache.jasper.runtime.PageContextImpl._initialize(PageContextImpl.java:147)
	org.apache.jasper.runtime.PageContextImpl.initialize(PageContextImpl.java:126)
	org.apache.jasper.runtime.JspFactoryImpl.internalGetPageContext(JspFactoryImpl.java:112)
	org.apache.jasper.runtime.JspFactoryImpl.getPageContext(JspFactoryImpl.java:65)
	org.apache.jsp.list_jsp._jspService(list_jsp.java:55)
	org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
	org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:432)
	org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:390)
	org.apache.jasper.servlet.JspServlet.service(JspServlet.java:334)
	javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
	org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
	org.nutz.mvc.NutFilter.nextChain(NutFilter.java:230)
	org.nutz.mvc.NutFilter.doFilter(NutFilter.java:205)

note The full stack trace of the root cause is available in the Apache Tomcat/7.0.54 logs.

项目发布到服务器之后，index页面正常访问，输入数据查询就报错，，，求解。。。