各位高手麻烦帮我看下面这三个文件(一个jsp,两个.java),我在ie输入地址时,提示如下错误(代码应该没有错,不知是不是设置的问题),望高手指教,不胜感激:

d:\program files\apache group\tomcat 4.1\work\standalone\localhost\_\shopping\index_jsp.java:44: package mybean does not exist
      mybean.dbconnmanager connmanager = null;
            ^



an error occurred at line: 2 in the jsp file: /shopping/index.jsp

generated servlet error:
d:\program files\apache group\tomcat 4.1\work\standalone\localhost\_\shopping\index_jsp.java:46: package mybean does not exist
        connmanager = (mybean.dbconnmanager) pagecontext.getattribute("connmanager", pagecontext.application_scope);
                             ^



an error occurred at line: 2 in the jsp file: /shopping/index.jsp

generated servlet error:
d:\program files\apache group\tomcat 4.1\work\standalone\localhost\_\shopping\index_jsp.java:49: package mybean does not exist
            connmanager = (mybean.dbconnmanager) java.beans.beans.instantiate(this.getclass().getclassloader(), "mybean.dbconnmanager");
                                 ^

//下面这两个是连接池,下面两个文件都放在一个mybean的包里.

package mybean;
import java.sql.*;
import java.util.*;

public class dbconnpool {
  //正在使用连接的数量
  private int using;
  //目前可用的连接数,即空闲连接
  private vector connections=new vector();
  //最大连接数
  private int maxconn;
  //连接池名
  private string poolname;
  //数据库标识
  private string dbid;
  //驱动程序名
  private string drivername;
  //数据库帐号
  private string username;
  //数据库密码
  private string passwd;

  public dbconnpool(string poolname,string dbid,string drivername,
                    string username,string passwd,int maxconn){
    this.poolname=poolname;
    this.drivername=drivername;
    this.dbid =dbid;
    this.username =username;
    this.passwd=passwd;
    this.maxconn=maxconn;
  }

  /*将空闲连接返回给连接池*/
  public synchronized void returnconnection(connection conn){
    //将指定连接加到向量末尾
    connections.addelement(conn);
    //连接用户减一
    using--;
  }

  /*从连接池得到一个连接*/
  public synchronized connection getconnection(){
    connection conn = null; //connection是一个类,
    //connections是一个向量,用于存储连接对象,它所存储是的所有空闲状态的可用连接
    if (connections.size() > 0) {

      //获取连接列表的第一个连接
      conn = (connection) connections.elementat(0);
      connections.removeelementat(0);//获得一个连接,并将此连接从队列中删除.

      //如果此连接已关闭,刚继续获取,
      try {
        if (conn.isclosed())
          conn = getconnection();
      }
      catch (exception e) {
        e.printstacktrace();
      }
    }
      //如果实际使用的连接数小于最大连接数即有可用连接),就新增加一个连接
    else if (maxconn == 0 || using < maxconn){
      //如此时无可用连接(maxconn == 0)且连接数又未达到上限(using < maxconn)),就创建一个新连接
        conn=newconnection();
      }
      //如果连接数已达到上限就返回空指针
      if (conn!=null){
        using++;
      }
    return conn;
  }

/*创建新的连接*/
  public connection newconnection(){
    connection conn=null;
    try{
      //加载驱动
      class.forname(drivername);
      conn=drivermanager.getconnection(dbid,username,passwd);
    }catch(exception e){
      e.printstacktrace();
      return null;
    }
    return conn;
  }

 /*关闭所有连接*/
 public synchronized void closeconn(){
   enumeration allconnections=connections.elements();
   while (allconnections.hasmoreelements()){
     connection conn=(connection) allconnections.nextelement();
     try{
       conn.close();
     }catch(sqlexception e){
       e.printstacktrace();
     }
   }
   connections.removeallelements();
 }
}

package mybean;
import java.sql.*;
import java.util.*;

public class dbconnmanager {
  //连接池名列表
  private vector poolnames =new vector();
  //驱动程序名列表
  private vector drivernames=new vector();
  //数据库标识列表
  private vector dbids=new vector();
  //用户名列表
  private vector usernames=new vector();
  //用户密码列表
  private vector passwds=new vector();
  //最大连接数列表
  private vector maxconns=new vector();
  //连接池队列
  private hashtable connpools=new hashtable();

  public dbconnmanager() {
    //添加access数据库的连接信息
    poolnames.addelement("access");
    drivernames.addelement("sun.jdbc.odbc.jdbcodbcdriver");
    dbids.addelement("jdbc:odbc:shopping");
    usernames.addelement("");
    passwds.addelement("");
    maxconns.addelement("5");

    //添加sql server2000数据库的连接信息
    poolnames.addelement("sqlserver2000");
    drivernames.addelement("com.microsoft.jdbc.sqlserver.sqlserverdriver");
    dbids.addelement("jdbc:microsoft:sqlserver://localhost:1433;databsername=shopping");
    usernames.addelement("");
    passwds.addelement("");
    maxconns.addelement("5");

    //连接mysql数据库信息
    poolnames.addelement("mysql");
    drivernames.addelement("org.gjt.mm.mysql.driver");
    dbids.addelement("jdbc:mysql://localhost/shopping");
    usernames.addelement("");
    passwds.addelement("");
    maxconns.addelement("5");

    //连接oracle8i/9i数据库
    poolnames.addelement("oracle");
    drivernames.addelement("oracle.jdbc.driver.oracledriver");
    dbids.addelement("jdbc:oracle:thin:@localhost:1521:shopping");
    usernames.addelement("");
    passwds.addelement("");
    maxconns.addelement("5");

    //创建连接池
    createpools();
  }

  /*将连接返回给由指定的连接池*/
  public void returnconnection(string name,connection conn){
    dbconnpool pool=(dbconnpool) connpools.get(name);
    if (pool!=null)
    {
      pool.returnconnection(conn);
    }
  }

  /*得到一个指定连接池中的连接*/
  public connection getconnection(string name){
    dbconnpool pool=(dbconnpool) connpools.get(name);
    if (pool!=null)
    {
      return pool.getconnection();
    }
    return null;
  }

  /*关闭所有连接*/
  public synchronized void closeconns(){
    enumeration allpools=connpools.elements();
    while (allpools.hasmoreelements()){
      dbconnpool pool=(dbconnpool) allpools.nextelement();
      pool.closeconn();
    }
  }

  /*创建连接池*/
  private void createpools(){
    for (int i=0;i<poolnames.size();i++)
    {
      string poolname=poolnames.elementat(i).tostring();
      string drivername=drivernames.elementat(i).tostring();
      string dbid=dbids.elementat(i).tostring();
      string username=usernames.elementat(i).tostring();
      string passwd=passwds.elementat(i).tostring();
      int maxconn=0;
      try{
        maxconn=integer.parseint(maxconns.elementat(i).tostring());
      }catch (numberformatexception e){
        e.printstacktrace();
      }
      dbconnpool pool=new dbconnpool(poolname,drivername,dbid,username,
                                     passwd,maxconn);
      connpools.put(poolname,pool);
    }
  }
}

下面这个是主页面.jsp文件

<%@ page contenttype="text/html; charset=gbk" %>
<%@ page import ="java.sql.*" %>
<jsp:usebean id="connmanager" scope="application" class="mybean.dbconnmanager" />
<html>
<head>
<title>
购物商城首页
</title>
</head>
<body bgcolor="#b0c4de">
<center><h1>欢迎访问本购物商城</h1></center>
<%
//connection conna=connmanager.getconnection("access");
connection conns=connmanager.getconnection("sqlserver2000");
if (conns==null)
{
%>
  数据库正忙,请稍后再访问
<%
}
//statement stmta=conna.createstatement();
statement stmts=conns.createstatement();
%>

<%
string sql="select * from userinfo";
resultset rs=stmts.executequery(sql);
while (rs.next())
{
%>
<tr>
<td><%=rs.getstring("username")%></td>
<td><%=rs.getstring("userpass")%></td>
</tr>
<%
}
rs.close();
stmts.close();
connmanager.returnconnection("sqlserver2000",conns);
%>

</body>
</html>