无法连接数据库

<%@ page pageEncoding="GB2312"%>
<%@ page contentType="text/html;charset=gb2312"%>
<%@ page import="java.util.*"%>
<%@ page import="java.sql.*" %>
<%@ page import="javax.sql.*"%>
<%@ page import="com.mysql.jdbc.Driver"%><html>
<head>
<title>connection</title>
</head><body><% 
  request.setCharacterEncoding("gb2312");
  String CLASSFORNAME="org.gjt.mm.mysql.Driver";
  String SERVANDDB="jdbc:mysql://localhost:3306/cn";
  String USER="root";
  String PWD="123";
  String sql=null;
  Connection con=null;
  Statement stmt=null;
  
   try{
        
       Class.forName("CLASSFORNAME").newInstance();
      }
   catch(Exception e)
     { System.out.println("加载驱动器类时出现异常");
      }   
   
   try{
       con=DriverManager.getConnection(SERVANDDB,USER,PWD);
       stmt=con.createStatement();
       sql="select * from comessage";
       ResultSet rs=stmt.executeQuery(sql);
       
        while(rs.next()){
          String CoID=rs.getString(1);
          String Coname=rs.getString(2);
          String phone=rs.getString(3);
          String fax=rs.getString(4);
          String email=rs.getString(5);
          String id=rs.getString(6);
          String country=rs.getString(7);
          String province=rs.getString(8);
          String city=rs.getString(9);
          String address=rs.getString(10);
          
          System.out.println(CoID+""+Coname+""+phone+""+fax+""+email+""+id+""+country+""+province+""+city+""+address);
         }
        
        rs.close();
        stmt.close(); 
     }
  catch(Exception ex)
    {
      System.out.println("出现SQL Exception异常");
    }finally{
         
         try{
              if(con!=null)con.close();
            }catch(Exception ex){
               System.out.println("关闭数据库连接时出现异常");
            }
        
      }   
     
  
  
 %> 
 
</body>
</html>
运行完后TOMCAT提示 加载驱动器类时出现异常  出现SQL Exception异常
请大侠们帮忙看下哪里错了  要做如何修改才能正常连接到数据库？