public   class  DBHelper  {    
    
public   static  Connection getConnection()  {    
        Connection conn 
=   null ;    
        
try   {    
            Class.forName(
" com.mysql.jdbc.Driver " );    
            conn 
=  DriverManager.getConnection( " jdbc:mysql://localhost/ad?useUnicode=true&characterEncoding=GBK&jdbcCompliantTruncation=false " ,    
                    
" root " " root " );    
        }
  catch  (Exception e)  {    
            e.printStackTrace();    
        }
    
        
return  conn;    
    }
    
}
    
   
        
/* dao中的方法 */    
    
public  List < Adv >  getAllAdvs()  {    
            
        Connection conn 
=   null ;    
        ResultSet rs 
=   null ;    
        PreparedStatement stmt 
=   null ;    
        String sql 
=   " select * from adv where id = ? " ;    
        List
< Adv >  advs  =   new  ArrayList < Adv > ();    
   
        conn 
=  DBHelper.getConnection();    
        
if  (conn  !=   null {    
            
try   {    
                stmt 
=  conn.prepareStatement(sql);    
                                stmt.setInt(
1 new  Integer( 1 ));    
                rs 
=  stmt.executeQuery();    
   
                
if  (rs  !=   null {    
                    
while  (rs.next())  {    
                        Adv adv 
=   new  Adv();    
                        adv.setId(rs.getLong(
1 ));    
                        adv.setName(rs.getString(
2 ));    
                        adv.setDesc(rs.getString(
3 ));    
                        adv.setPicUrl(rs.getString(
4 ));    
   
                        advs.add(adv);    
                    }
    
                }
    
            }
  catch  (SQLException e)  {    
                e.printStackTrace();    
            }
  finally   {    
                
try   {    
                    stmt.close();    
                    conn.close();    
                }
  catch  (SQLException e)  {    
                    e.printStackTrace();    
                }
    
            }
    
        }
    
        
return  advs;    
    }