在eclipse下不能用javabean
小弟初学JSP，现在正在用eclipse
我按照书上和到网上找的资料配置好了开发环境后，JSP却一直不能正常运行，但又发现不了错误，只能来麻烦大家了，请帮帮忙

下面是我写的两个JAVABEAN和JSP文件

package   wen;
import   java.sql.*;
import   java.io.*;
import   java.util.Properties;
public   class   DBConnection  
{              
   
private   static   String   driver;
private   static   String   serverURL;
private   static   String   username;
private   static   String   password;
private   static   Connection   conn   =   null;
private   static   Statement   stmt   =   null;
private   static   String   connectionFileName= "connection.txt ";
private   String   str;

private   static   Object   initLock   =   new   Object();

    public   Connection   getConn()   {
            return   conn;
    }



public   static   Connection   getConnection()
{
                   
                   
if(conn   ==   null){
synchronized(initLock){
loadProperties();
try{
Class.forName(driver);
}
catch(ClassNotFoundException   e){
System.out.println(e.toString());
}
try{
conn   =   DriverManager.getConnection(serverURL,username,password);
}
catch(SQLException   e){
System.out.println(e.toString());
}
}

}
return   conn;
}


public   static   void   loadProperties(){
Properties   connectionAdmin   =   new   Properties();
System.out.println( "连接配置文件： "   +   connectionFileName);
try{
connectionAdmin.load(new   FileInputStream(connectionFileName));
}
catch(IOException   e){
System.out.println( "找不到文件 "   +   connectionFileName);
System.out.println(e.toString());
}
driver   =   (String)connectionAdmin.get( "driver ");
serverURL   =   (String)connectionAdmin.get( "serverURL ");
username   =   (String)connectionAdmin.get( "username ");
password   =   (String)connectionAdmin.get( "password ");

}

public   static   ResultSet   exec(String   sql){
ResultSet   rs   =   null;
try{
if(conn   ==   null){
getConnection();
}
Statement   stmt   =   conn.createStatement();
rs   =   stmt.executeQuery(sql);
}catch(SQLException   ex){
ex.printStackTrace();
}
return   rs;
}

｝


package   wen;
import   java.sql.*;

public   class   IndexBean   {



public     ResultSet   getMoban(){