<%--
Document : vote
Created on : 2011-9-15, 15:56:46
Author : Administrator
--%>
<%@page contentType="text/html" pageEncoding="GB2312"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<%@page language="java" import="java.sql.*"%>
<jsp:useBean id="connDbBean" scope="page" class="vote.VoteConn"/>
<%
String rb = request.getParameter("type");
if(rb != null && rb != "") {
String sql = "update vote Set c_num=c_num+1 where id=" + rb;
connDbBean.executeUpdate( sql );
}
%>
<jsp:forward page="details.jsp"/>
报错：
HTTP Status 500 -
--------------------------------------------
type Exception report
message
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 /vote.jsp at line 20
17: connDbBean.executeUpdate( sql );
18: }
19: %>
20: <jsp:forward page="details.jsp"/>
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:510)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:401)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
root cause
org.apache.jasper.JasperException: An exception occurred processing JSP page /details.jsp at line 28
25: <%
26: // 获取总票数
27: ResultSet tmpRs = connDbBean.executeQuery("select sum(c_num) As totalnum from vote");
28: tmpRs.next();
29: tot_num = tmpRs.getInt("totalnum");
30: tmpRs.close();
31: ResultSet rs = connDbBean.executeQuery("select * from vote");
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:510)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:419)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
org.apache.jasper.runtime.PageContextImpl.doForward(PageContextImpl.java:706)
org.apache.jasper.runtime.PageContextImpl.forward(PageContextImpl.java:677)
org.apache.jsp.vote_jsp._jspService(vote_jsp.java:79)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:377)
org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)
org.netbeans.modules.web.monitor.server.MonitorFilter.doFilter(MonitorFilter.java:393)
root cause
java.lang.NullPointerException
org.apache.jsp.details_jsp._jspService(details_jsp.java:86)
org.apache.jasper.runtime.HttpJspBase.service(HttpJspBase.java:70)