请教：cannot find symbol

报这个错是什么意思啊，谢谢！！
cannot find symbol
symbol:class IOException
location:class org.apache.jsp.site2.bbs.forum_jsp
throws IOException{
^
Note: D:\Tomcat\work\catalina\localhost\_\org\apache\jsp\site2\bbs\forum_jsp.java uses or overrides a deprecated API.
Note:Recompile with -Xlint:deprecation for details.

解决方案 »

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IOException没有找到
没有使用import java.io.IOException吧
代码下面：
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<%@ page contentType="text/html;charset=gb2312" %><% String getLoginmessage = (String) session.getValue("loginSign");
 if(getLoginmessage!="OK"){
%>
<script language=javascript>
 window.location="refuse.jsp"
</script>
<% }
%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>论坛</title><base target="_self">
</head>
<body topmargin="5"><%@ page language="java" import="java.sql.*" import="java.net.*" import="java.io.*"%>
<%! String board; %>
<jsp:useBean id="workM" scope="page" class="DataBase.MyDbBean" />

<%
//分页的策略：每页参考行数为10行，主题数totalSub/( 总记录totalRec/参考行数PageLine) =平均每页的主题数量totalSubPerPage
//此后页数和第几个主题可以有一个对应关系
int pageLine=6;
int totalRec=0;
int totalSub=0;
int pageNo=1;

board = request.getParameter("board");
//board=session.getValue("board");

String temp = (String) session.getValue("board");
if(board==null) board=temp;


if (request.getParameter("page")!=null)
pageNo=Integer.parseInt(request.getParameter("page"));

try{
//out.print(board);
ResultSet countrs=null;
//指定参考行数

//取得总数
workM.OpenConn("dboard","","");
countrs=workM.executeQuery("select count(*) as cnt from " + board);
if (countrs.next())
totalRec=countrs.getInt("cnt");
countrs.close();
workM.closeStmt();
//取得主题数
countrs=workM.executeQuery("select count(*) as cnt from " + board + " where parent_no=0");
if (countrs.next())
totalSub=countrs.getInt("cnt");
countrs.close();
workM.closeStmt();

}
catch(Exception e){
 e.printStackTrace();
}

//取得每行的主题数量
int jtemp=totalRec/pageLine+1;
//int totalSubPerPage=totalSub/jtemp;
int totalSubPerPage=10;
//取得总页数
int totalPage=0;
totalPage=(totalSub/totalSubPerPage * 10 + 5)/10 ;
%>
<table border="0" width="100%" cellspacing="1" cellpadding="0" bgcolor="#EEEEEE">
 <tr>
 <td width="60%">

论坛：<%=board%>

 </td>
 <td width="40%">
 <a href="search.htm" target="_blank">检索</a>  
 <a href="forum.jsp?board=<%=board%>">刷新</a>    <a href="addtopic.jsp?board=<%=board%>" target="rbottom">增加新帖</a>   
  <a href="myindex.jsp" target="_top">返回主页</a></td>
 </tr>
</table>

<%
out.print("<table border='0' width='100%' cellspacing='1' cellpadding='0'>");
out.print("<tr bgcolor='#CCFFCC'><td>标题</td><td bgcolor='#CCFFCC'>发表人</td>");
out.print("<td bgcolor='#CCFFCC'>发表时间</td><td>回复数</td><td bgcolor='#CCFFCC'>点击数</td></tr>");

String serial;
String title;
String speaker;
Date providedate;
int reply;
int click;

ResultSet RS=workM.executeQuery("select * from " + board + " where parent_no=0 order by serial_no DESC");

int i=0; //循环计数
while (RS.next()) {
 i++;
 if (i>(totalSubPerPage *(pageNo-1)) && (i<=(pageNo * totalSubPerPage))){
// out.print(totalSubPerPage *(pageNo-1));
// out.print(pageNo * totalSubPerPage);
 out.print("<tr bgcolor='#f2f2e6'><td>");
 serial=RS.getString("serial_no");
 title=RS.getString("title");
 speaker=RS.getString("speaker");
 providedate=RS.getDate("provide_time");
 reply=RS.getInt("reply_num");
 click=RS.getInt("click_num");
 showing(request,out,serial,title,speaker,providedate,reply,click,"Subject");

 //这里要显示下一级的回复内容
 ResultSet RS1 = workM.executeQuery("select * from " + board + " where parent_no=" + serial + " order by serial_no");
 while (RS1.next()) {
 out.print("<tr bgcolor='#f3f3e6'><td>");
 serial=RS1.getString("serial_no");
 title=RS1.getString("title");
 speaker=RS1.getString("speaker");
 providedate=RS1.getDate("provide_time");
 reply=RS1.getInt("reply_num");
 click=RS1.getInt("click_num");
 showing(request,out,serial,title,speaker,providedate,reply,click,"Re");
 }
 RS1.close();
 workM.closeStmt();
 //------------------------
 }
}
out.print("</table>");
RS.close();
workM.closeStmt();
out.print("共有发言"+ totalRec + "条，分为" + totalPage + "页显示 "); for(int j=1;j<=totalPage;j++){
 if(j%10==0) out.print(" ");
 out.print("<a href=forum.jsp?board=" + board + "&page=" + j + ">");
 if (j==pageNo)
 out.print("" + j + "");
 else
 out.print(j);
 out.print("</a> ");
}
%>


<%!
 void showing(HttpServletRequest request,JspWriter out,String serial,String title,String speaker, Date providedate,int reply,int click,String ReSign)
 throws IOException {
 if(ReSign=="Subject"){
 out.print("<a href=forumcontent.jsp?board=" + board + "&serial=" + serial + " target=rbottom>" + title + "</a>");
 }
 else{
 out.print(" Re:<a href=forumrecontent.jsp?board=" + board + "&serial=" + serial + " target=rbottom>" + title + "</a>");
 }
 out.print("</td><td>");
 out.print(speaker);
 out.print("</td><td>");
 out.print(providedate);
 out.print("</td><td>");
 out.print(reply);
 out.print("</td><td>");
 out.print(click);
 out.print("</td></tr>");
}
%>
　

</body>
</html>
加了import java.io.*的。为什么？
改下第一行
<%@ page contentType="text/html;charset=gb2312" import="java.io.*" %>
就OK了