BBS中article.jsp文件，提示不能被编译

严重: Servlet.service() for servlet jsp threw exception
org.apache.jasper.JasperException: Unable to compile class for JSP: An error occurred at line: 8 in the jsp file: /article.jsp
Unhandled exception type SQLException
5:   private void tree(List<Article> articles,Connection conn, int id, int grade){
6:   String sql = "select * from article where pid = "+id;
7:   Statement stmt = DB.getstmt(conn);
8:   ResultSet rs =  stmt.executeQuery(sql);
9:   try{
10:       while(rs.next()){
11:             Article a = new Article(); 
jsp源码：<%@ page pageEncoding="GB18030"%>
<%@ page import = "java.sql.*,com.yl.bbs.*,java.util.*" %><%!
  private void tree(List<Article> articles,Connection conn, int id, int grade){
  String sql = "select * from article where pid = "+id;
  Statement stmt = DB.getstmt(conn);
  ResultSet rs =  stmt.executeQuery(sql);
  try{
      while(rs.next()){
            Article a = new Article(); 
            a.setId(rs.getInt("id"));
            a.setPid(rs.getInt("pid"));
            a.setRootId(rs.getInt("rootid"));
            a.setTitle(rs.getString("title"));
            a.setPdate(rs.getTimestamp("pdate"));
            a.setIsleaf(rs.getInt("isleaf") == 0 ? true : false);
            a.setGrade(grade);
            articles.add(a);
            if(!a.isIsleaf()){
               tree(articles,conn,a.getId(),grade+1);
            }
      }
  }catch(SQLException e){
        e.printStackTrace();
  }
  }
%><%
  List<Article> articles = new ArrayList<Article>();
  Connection conn = DB.getconn();
  tree(articles,conn,0,0);
  DB.close(conn);
%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title>Java语言*初级版</title>
<meta http-equiv="content-type" content="text/html; charset=utf8">
<link rel="stylesheet" type="text/css" href="images/style.css" title="Integrated Styles">
<script language="JavaScript" type="text/javascript" src="images/global.js"></script>
<link rel="alternate" type="application/rss+xml" title="RSS" href="http://bbs.chinajavaworld.com/rss/rssmessages.jspa?forumID=20">
<script language="JavaScript" type="text/javascript" src="images/common.js"></script>
</head>
<body>
<table border="0" cellpadding="0" cellspacing="0" width="100%">
  <tbody>
    <tr>
      <td width="40%"><br>av<img src="images/header-stretch.gif" alt="" border="0" height="57" width="100%">
      </td>
      <td width="1%"><img src="images/header-right.gif" alt="" height="57" border="0"></td>
    </tr>
  </tbody>
</table>
<br>
<div id="jive-forumpage">
  <table border="0" cellpadding="0" cellspacing="0" width="100%">
    <tbody>
      <tr valign="top">
        <td width="98%"><p class="jive-breadcrumbs">论坛: Java语言*初级版
            (模仿)</p>
          <p class="jive-description"> 探讨Java语言基础知识,基本语法等 大家一起交流 共同提高！谢绝任何形式的广告 </p>
          </td>
      </tr>
    </tbody>
  </table>
  <div class="jive-buttons">
    <table summary="Buttons" border="0" cellpadding="0" cellspacing="0">
      <tbody>
        <tr>
          <td class="jive-icon"><a href="post.jsp"><img src="images/post-16x16.gif" alt="发表新主题" border="0" height="16" width="16"></a></td>
          <td class="jive-icon-label"><a id="jive-post-thread" href="post.jsp">发表新主题</a> <a href="http://bbs.chinajavaworld.com/forum.jspa?forumID=20&amp;isBest=1"></a></td>
        </tr>
      </tbody>
    </table>
  </div>
  <br>
  <table border="0" cellpadding="3" cellspacing="0" width="100%">
    <tbody>
      <tr valign="top">
        <td><span class="nobreak"> 页:
          1,316 - <span class="jive-paginator"> [ <a href="http://bbs.chinajavaworld.com/forum.jspa?forumID=20&amp;start=0&amp;isBest=0">上一页</a> | <a href="http://bbs.chinajavaworld.com/forum.jspa?forumID=20&amp;start=0&amp;isBest=0" class="">1</a> <a href="http://bbs.chinajavaworld.com/forum.jspa?forumID=20&amp;start=25&amp;isBest=0" class="jive-current">2</a> <a href="http://bbs.chinajavaworld.com/forum.jspa?forumID=20&amp;start=50&amp;isBest=0" class="">3</a> <a href="http://bbs.chinajavaworld.com/forum.jspa?forumID=20&amp;start=75&amp;isBest=0" class="">4</a> <a href="http://bbs.chinajavaworld.com/forum.jspa?forumID=20&amp;start=100&amp;isBest=0" class="">5</a> <a href="http://bbs.chinajavaworld.com/forum.jspa?forumID=20&amp;start=125&amp;isBest=0" class="">6</a> | <a href="http://bbs.chinajavaworld.com/forum.jspa?forumID=20&amp;start=50&amp;isBest=0">下一页</a> ] </span> </span> </td>
      </tr>
    </tbody>
  </table>
  <table border="0" cellpadding="0" cellspacing="0" width="100%">
    <tbody>
      <tr valign="top">
        <td width="99%"><div class="jive-thread-list">
            <div class="jive-table">
              <table summary="List of threads" cellpadding="0" cellspacing="0" width="100%">
                <thead>
                  <tr>
                    <th class="jive-first" colspan="3"> 主题 </th>
                    <th class="jive-author"> <nobr> 作者
                      &nbsp; </nobr> </th>
                    <th class="jive-view-count"> <nobr> 浏览
                      &nbsp; </nobr> </th>
                    <th class="jive-msg-count" nowrap="nowrap"> 回复 </th>
                    <th class="jive-last" nowrap="nowrap"> 最新帖子 </th>
                  </tr>
                </thead>
                <tbody>
                <%
                   for(Iterator<Article> it = articles.iterator();it.hasNext();){
                        Article a = it.next();               
                 %>
                
                  <tr class="jive-even">
                    <td class="jive-first" nowrap="nowrap" width="1%"><div class="jive-bullet"> <img src="images/read-16x16.gif" alt="已读" border="0" height="16" width="16">
                        <!-- div-->
                      </div></td>
                      
                    <td nowrap="nowrap" width="1%">=
     
                    </td>
                    
                    
                    <td class="jive-thread-name" width="95%">rt</td>
                    <td class="jive-author" nowrap="nowrap" width="1%"><span class=""> <a href="http://bbs.chinajavaworld.com/profile.jspa?userID=226030">bjsxt</a> </span></td>
                    <td class="jive-view-count" width="1%"> 10000</td>
                    <td class="jive-msg-count" width="1%"> 0</td>
                    <td class="jive-last" nowrap="nowrap" width="1%"><div class="jive-last-post">  <br>
                        by: <a href="http://bbs.chinajavaworld.com/thread.jspa?messageID=780182#780182" title="jingjiangjun" style="">bjsxt &#187;</a> </div></td>
                  </tr>
               
                  <tr class="jive-odd">
                    <td class="jive-first" nowrap="nowrap" width="1%"><div class="jive-bullet"> <img src="images/read-16x16.gif" alt="已读" border="0" height="16" width="16">
                        <!-- div-->
                      </div></td>
                    <td nowrap="nowrap" width="1%">&nbsp;
                      
                      
                      
                      
                      &nbsp;</td>
                    <td class="jive-thread-name" width="95%"><a id="jive-thread-2" href="http://bbs.chinajavaworld.com/thread.jspa?threadID=744234&amp;tstart=25">请 兄弟们指点下那里 错误，，，</a></td>
                    <td class="jive-author" nowrap="nowrap" width="1%"><span class=""> <a href="http://bbs.chinajavaworld.com/profile.jspa?userID=226028">403783154</a> </span></td>
                    <td class="jive-view-count" width="1%"> 52</td>
                    <td class="jive-msg-count" width="1%"> 2</td>
                    <td class="jive-last" nowrap="nowrap" width="1%"><div class="jive-last-post"> 2007-9-13 上午8:40 <br>
                        by: <a href="http://bbs.chinajavaworld.com/thread.jspa?messageID=780172#780172" title="downing114" style="">downing114 &#187;</a> </div></td>
                  </tr>               <%
                 }               
                %>
                </tbody>
              </table>
            </div>
          </div>
          <div class="jive-legend"></div></td>
      </tr>
    </tbody>
  </table>
  <br>
  <br>
</div>
</body>
</html>