数据查询while(rs.next)错误

学习jsp 写在线书店的查询的时候出错了 不知道怎么办了
这个是现实错误代码org.apache.jasper.JasperException: An exception occurred processing JSP page /search.jsp at line 6259:     myPage.pageId=1;
60:     Vector idList=new Vector();
61:     getPage="1";
62:     while(rs.next())
63:     {
64:        myPage.recordCount++;
65:        if(myPage.recordCount==myPage.pageSize)
源文件代码<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<%
String path = request.getContextPath();
String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
%><!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<SCRIPT language=JavaScirpt src="JSLib.js" type="text/javascript"></SCRIPT>
<SCRIPT language=JavaScript>
function checkform(Frm){
      var flag=ture;
      if(isInt(Frm.pageId.value))
      {
          alert("用户名不能为空！");
          Frm.pageId.focus();
          flag=false;
      }
      retrun flag;
}
function detail(a)
{
    windows.open("detail.jsp?pid="+a,"body","toolbar=no,left=150,top=20,width=480,height=350,meaubar=no,systemMenu=no");
}
function add(a)
{
    windows.open("add.jsp?pid="+a,"body","toobar=no,left=150,top=20,width=300,height=50,menubar=no,systemMenu=no");
    
}</script>
<%@ page import="java.sql.*" %>
<%@ page import="page.Page"%>
<jsp:useBean id="db" scope="page" class="opendb.opendb"/>
<%
String getPage=request.getParameter("pageId").trim();
if(getPage.compareTo("-1")==0)
{
    Page myPage=new Page();
    String bookname=request.getParameter("bookname").trim();
    String author=request.getParameter("author").trim();
    String nameSelect="";
    String authorSelect="";
    if(bookname.compareTo("")!=0) nameSelect="bookname like'%"+bookname+"%'";
    if(author.compareTo("")!=0) authorSelect="author like'%"+author+"%'";
    byte[] tmpbyte=nameSelect.getBytes("ISO8859_1");
    nameSelect=new String(tmpbyte);
    tmpbyte=authorSelect.getBytes("ISO8859_1");
    authorSelect=new String(tmpbyte);
    if(authorSelect.compareTo("")!=0&&nameSelect.compareTo("")!=0)nameSelect="and"+nameSelect;
    String sql="select pid frombook where";
    sql=sql+authorSelect+nameSelect+"order by pid desc";
    session.putValue("authorSelect", authorSelect);
    session.putValue("nameSelect", nameSelect);
    ResultSet rs=db.executeQuery(sql);
    myPage.recordCount=0;
    myPage.pageSize=10;
    myPage.pageCount=0;
    myPage.pageId=1;
    Vector idList=new Vector();
    getPage="1";
    while(rs.next())
    {
       myPage.recordCount++;
       if(myPage.recordCount==myPage.pageSize)
       {   
           myPage.pageCount++;
           idList.addElement(rs.getString("pid"));
           myPage.recordCount=0;
       }
      
    }
    if(myPage.recordCount!=0) myPage.pageCount++;
    myPage.recordCount+=(myPage.pageCount-1)*myPage.pageSize;
    rs.close();
    session.putValue("idList",idList);
    session.putValue("myPage",myPage);
   }
 %>  <head>
   
    
    <title>用户查询结果</title>
    
<meta http-equiv="Content-Type" content="text/html;charset=gb2312">
  </head>
  <style type="text/css">
  <!--import"css/jsp.css";-->
  </style>  
  <body bgcolor="#FFFFFF">
  <%boolean pageError=false;
  Page myPage=(Page)session.getValue("myPage");
  if(myPage.recordCount<=0)
  { %>对不起，没有您需要的商品，请扩大查询范围！<%}
  else
  { 
        int pageId=myPage.pageId;
        if(getPage!=null&&getPage!="") pageId=Integer.parseInt(getPage.trim());
        if(pageId<1 ||pageId>myPage.pageCount)
        {
            pageId=myPage.pageId;
            pageError=true;
            }
        myPage.pageId=pageId;
        Vector idList=(Vector)session.getValue("idList");
        String getList="";
        if(pageId>1)
        {
            getList=(String) idList.elementAt(pageId-2);
            getList="and pid<"+getList;
        }
        String authorSelect=(String)session.getValue("authorSelect"); 
        String nameSelect=(String)session.getValue("nameSelect");
        String sql="select top"+myPage.pageSize+"from book where";
        sql=sql+authorSelect+nameSelect+getList+"order by pid desc";
        ResultSet rs=db.executeQuery(sql);
        
           
        
        %><br>
        <table width="540" border="0">
        <tr>
           <td width="25%"><b><font color="#FF0000">◎</font></b>共有记录<b>
           <font color="#FF0000"><%=myPage.recordCount%></font></b>条</td>
           <td width="30%"><%if(pageError){%>您输入的页码无效<%}%></td>
         <td width="45%">共有<b><font color="#FF0000"><%=myPage.pageCount %>
         </font></b>页，现在显示的事第
               <b><font color="#FF0000"><%=myPage.pageId %></font></b>页
               </td>
               </tr>
               </table>
               <table width="540" border="0">
               <tr bgcolor="#ff5d26">
               <td width="42">
               <div align="center"><font color="#FFFFFF"><b>记录是</b></font></div>
               </td>
               <td width="133">
               <div align="center"><font color="#FFFFFF">书名</font></div>
               </td>
               <td width="113">
               <div align="center"><font color="#FFFFFF"><b>作者</b></font></div>
               <td width="126" bgcolor="#ff5d26">
               <div align="center"><font color="#FFFFFF"><b>单价</b></font></div>
               </td>
               <td width ="104" bgcolor="#fff5d26">
               <div align="center"><font color="#FFFFFF"><b>放入购物车</b></font></div>
               </td>
               </tr>
               <%
               String pid;
               String bookname;
               String author;
               String price;
               int wsh=0;
               while(rs.next())
               {
                  wsh++;
                  pid=rs.getString("pid");
                  bookname=rs.getString("bookname");
                  author=rs.getString("author");
                  price=rs.getString("price");
               
                %>
                <tr bgcolor="#ffd6c8">
                <td width="42" height="13">
                <div align="center"><%=wsh+myPage.pageSize*(pageId-1)%></div>
                </td>
                <td width="133" height="13">
                <div align="center"><a href="javascript:detail(<%=pid%>);"><%=bookname%></a></div>
                </td>
                <td width="133" height="13">
                <div align="center"><%=author%></div>
                </td>
                <td width="126" bgcolor="#ffd6c8" height="13">
                <div align="center">￥<%=price%></div>
                </td>
                <td width="104" bgcolor="#ffd6c8" height="13">
                <div align="center"><a href="javascript:add(<%=pid%>);">购买</a></div>
                </td>
                </tr>
                <%}
                rs.close();
                %>
                </table>
                <table width="540" border="0">
                <tr>
                <td width="133">&nbsp;</td>
                <td width="397">
                <form name="form1" action="search.jsp" method="post" onsubmit="return checkform(this)">
                <%
                if(pageId!=1)
                {
                 %>
                 <a href="search.jsp?pageId=1">第一页</a>|<a href="search,jsp?pageId=<%=pageId-1%>">上一页</a>|<%}else{%>
                                                             第一页|上一页|
                 <%}
                 if(pageId!=myPage.pageCount)
                 {%>
                 <a href="search.jsp?pageId=<%=pageId+1%>">下一页</a>|
                 <a href="search.jsp?pageId=<%=myPage.pageCount%>">最后一页</a>
                 <%}else{%>
                                                              下一页|最后一个
                  <%}%>
                                                               输入页码 ：
                        <input type="text" name="PageId" size="5">
                                                                                      页数 : <b><font color="#FF0000"><%=myPage.pageId%></font></b>/
                  <b><font color="#FF0000"><%=myPage.pageCount%></font></b>
    </form>
     </td>
   </tr>
  </table>
  <%} %>
     
  </body>
</html>

解决方案 »

  1.   

    页面抛出异常后点击右键查看源代码，然后找到62行，如果是while(rs.next())这一行，那很大可能rs是null。
      

  2.   

     String sql="select pid frombook where";   from 后面有空格  大哥
      

  3.   

    就是while(rs.next())这一行 啊   具体真么解决啊
      

  4.   

    就是while(rs.next())这一行 啊 具体真么解决啊
      

  5.   

    ResultSet rs=db.executeQuery(sql);
    下面输出一下
    System.out.print(rs);
    先看看值是不是为null
      

  6.   

    你把你的 sql语句在数据库里面执行一下  看看能不能查出来东西吧
      

  7.   

    是  null 那怎么解决 我菜鸟 刚接触jsp  老湿快让交作业了 发愁·····
      

  8.   

    你的sql有问题   检查sql吧
      

  9.   

    是null要看是什么情况，如果是你的sql语句的问题那就要把语句改好，第二种是因为数据库没有数据所造成的，但是不管是那种情况你都需要在while(rs.next())外面加个判断:if(rs!=null){
        while(rs.next())
        ...
    }这样一来不管是什么情况造成的，里面的代码是不会执行的，也就不会抛出异常了，但是你还是要看看是否sql语句是否有问题，如果没有那就在数据库加些数据就可以了。
      

  10.   

      可能是Sql语句出问题了
      

  11.   

    String getPage=request.getParameter("pageId").trim();
    if(getPage.compareTo("-1")==0)
    {
        Page myPage=new Page();
        String bookname=request.getParameter("bookname").trim();
        String author=request.getParameter("author").trim();
        String nameSelect="";
        String authorSelect="";
        if(bookname.compareTo("")!=0) nameSelect="bookname like '%"+bookname+"%'";
        if(author.compareTo("")!=0) authorSelect="author like '%"+author+"%'";
        byte[] tmpbyte=nameSelect.getBytes("ISO8859_1");
        nameSelect=new String(tmpbyte);
        tmpbyte=authorSelect.getBytes("ISO8859_1");
        authorSelect=new String(tmpbyte);
        if(authorSelect.compareTo("")!=0&&nameSelect.compareTo("")!=0)nameSelect=" and "+nameSelect;
        String sql="select pid from book where ";
        sql=sql+authorSelect+nameSelect+" order by pid desc";
        session.putValue("authorSelect",authorSelect);
        session.putValue("nameSelect",nameSelect);
        ResultSet rs=db.executeQuery(sql);
        
        myPage.recordCount=0;
        myPage.pageSize=10;
        myPage.pageCount=0;
        myPage.pageId=1;
        Vector idList=new Vector();
        getPage="1";
      
        while(rs.next())
        {
           myPage.recordCount++;
           if(myPage.recordCount==myPage.pageSize)
           {   
               myPage.pageCount++;
               idList.addElement(rs.getString("pid"));
               myPage.recordCount=0;
           
          }
        }
        if(myPage.recordCount!=0) myPage.pageCount++;
        myPage.recordCount+=(myPage.pageCount-1)*myPage.pageSize;
        rs.close();
        session.putValue("idList",idList);
        session.putValue("myPage",myPage);
     
    晕 还是不行
      

  12.   

    弱弱的问下，
    <html>
    <head>
    <script type="text/javascript">
    function check()
    {var x=document.getElementById("password");
       var y=document.getElementById("pasword1");
       if(x!=y){alert{"两次密码输入不相同！";return false  }
    }
    </script>  <title>newOperator</title>
    </head>
    <body>
    <form name="myname" action="" method="post" onsubmit="check();" >
    密码：<input type="password" id="password" value=""/></br>
    密码确认:<input type="password" id="password1" value=""/></br>
    <input type="submit" name="sbt" value="提交"/><br>
    </form>
    </body>
    这个脚本程序为什么就不执行