跪求大神解决下！JSP之间参数传递以及在JSP中调用bean连接mySQL数据库开展查询时出错，这个主要是做的机票查询页面
<%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
<%@ page import="javax.servlet.*" import="java.sql.*"%>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gbk" />
<title>机票查询</title>
<script type="text/javascript" src="js/mootools.js"></script>
<script type="text/javascript" src="js/calendar.rc4.js"></script>
<script type="text/javascript">
//<![CDATA[
window.addEvent('domready', function() {
myCal1 = new Calendar({ date1: 'd/m/Y' }, { direction: 1, tweak: {x: 6, y: 0} });
myCal2 = new Calendar({ date2: 'd/m/Y' }, { classes: ['dashboard'], direction: 1, tweak: {x: 3, y: -3} });
myCal3 = new Calendar({ date3: 'd/m/Y' }, { classes: ['i-heart-ny'], direction: 1, tweak: {x: 3, y: 0} });
});
//]]>
</script>
<link rel="stylesheet" type="text/css" href="css/iframe.css"/>
<link rel="stylesheet" type="text/css" href="css/calendar.css"/>
<link rel="stylesheet" type="text/css" href="css/dashboard.css"/>
<link rel="stylesheet" type="text/css" href="css/i-heart-ny.css"/>
<link rel="stylesheet" type="text/css" href="css.css"/>
</head>
<jsp:useBean id="be" class="com.hncz.bean" scope="request"></jsp:useBean>
<body>
<%
String flight_no="",dep="",des="",
dep_time="",arr_time="",ps="";
float price=0;
int sum=0;
%>
<div id="wrap">
<div id="top">
<div class="nothing"></div>
<div id="nav">
<ul>
<li><a href="query.jsp">机票查询</a></li>
<li><a href="book.jsp">机票预订</a></li>
<li><a href="refund.jsp">退票</a></li>
<li><a href="endorse.jsp">改签</a></li>
</ul>
</div>
</div>
<div id="main">
<div id="up">
<div id="upleft">
<form action="querycheck.jsp" class="long">
<fieldset>
<label>出发地</label>
<input id="input" type="text" name="dep" value=""/>
<label>目的地</label>
<input id="input" type="text" name="des" value=""/>
<label>出发日期</label>
<input id="date1" type="text" name="dep_date" value="" />
</fieldset>
</form>
</div>
<div id="upright">
<input id="button" type="submit" value="查询"/>
</div>
</div>
<div id="down">
<div id="container">
<table width="820" border="1" id="table">
<tr>
<th>航次</th>
<th>出发站</th>
<th>到达站</th>
<th>出发时间</th>
<th>到达时间</th>
<th>历时</th>
<th>余票</th>
<th>票价</th>
<th>备注</th>
</tr>
<%String sql=(String)session.getAttribute("sql");
ResultSet rs=be.query(sql);
if(!rs.next())
{
%>
<script>
alert("没有符合条件的机票，请你重新查询");
window.location.href="query.jsp"
</script>
<%
}
while(rs.next()){
flight_no=rs.getString("flight_no");
dep=rs.getString("dep");
des=rs.getString("des");
dep_time=rs.getString("dep_time");
arr_time=rs.getString("arr_time");
sum=rs.getInt("sum");
price=rs.getFloat("price");
ps=rs.getString("ps");
%>
<tr >
<td><%=flight_no %></td>
<td><%=dep %></td>
<td><%=des %></td>
<td><%=dep_time %></td>
<td><%=arr_time %></td>
<td><%=Integer.parseInt(arr_time)-Integer.parseInt(dep_time) %></td>
<td><%=sum %></td>
<td><%=price %></td>
<td><%=ps %></td>
</tr>
<%} %>
</table>
</div>
</div>
</div>
<div id="footer">Copyright © 2008-2013 滕州论坛 All rights All rights reserved. 来源:<a href="http://www.mycodes.net/" target="_blank">源码之家</a></div>
</div>
</body>
</html>
这是我的查询页面，输入的参数通过表单传递到下一个jsp页面
================================================================================================
<%@ page language="java" import="java.sql.*" pageEncoding="GBK"%>
<%@ page import="javax.servlet.*" %>
<html>
<head>
<title>验证注册表单</title>
</head>
<jsp:useBean id="be" class="com.hncz.bean" scope="request"/>
<body>
<%
String dep=new String(request.getParameter("dep").getBytes("ISO-8859-1"),"utf-8");
String des=new String(request.getParameter("des").getBytes("ISO-8859-1"),"utf-8");
String dep_date=request.getParameter("dep_date");
ResultSet rs=null;
if(dep.length()==0 || des.length()==0 || dep_date.length()==0)
{ %>
<script>
alert("查询条件不能为空");
window.location.href="query.jsp"
</script>
<%}
else{
String sql="select flight_no,dep,des,dep_time,arr_time"+
",arr_time-dep_time,sum,price,ps from flight where dep="
+dep+"and des="+des+"and dep_date="+dep_date;
//把获得的数据存放在session中
session.setAttribute("sql", sql);
}%>
</body>
</html>
===============================================================================================
每次出错的原因都是：
type Exception report
message An exception occurred processing JSP page /query.jsp at line 85
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 /query.jsp at line 85
82:
83: <%String sql=(String)session.getAttribute("sql");
84: ResultSet rs=be.query(sql);
85: if(!rs.next())
86: {
87: %>
88: <script>
Stacktrace:
org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:568)
org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:470)
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)
root cause
java.lang.NullPointerException
org.apache.jsp.query_jsp._jspService(query_jsp.java:157)
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)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.55 logs.
新人在此，有哪里不详细的地方
求包含 求解决！！！！
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若楼主采用的是java后台。。。可以使用Java中DataFormat