Validando login

private void entrarActionPerformed(java.awt.event.ActionEvent evt) {                                       
	
       
       
  
        
       
       try {
         ConnectionFactory conexao = new ConnectionFactory();
    
         conexao.getConnection();
         conexao.stmt = conexao.con.createStatement();

         String sql = "SELECT  login = ?, senha = ?"
                 + " FROM USUARIO";
         
         conexao.res = conexao.stmt.executeQuery(sql);
         conexao.res.first();
         conexao.res.next();
         
    
         if(textlogin.getText().equals(conexao.res.getString("login")) && textsenha.getPassword().equals(conexao.res.getString("senha"))){
             
             new Principal().setVisible(true);
         this.dispose();            
        
         JOptionPane.showMessageDialog(null," " +textlogin.getText()+ " Bem vindo ao Sistema |Diemp Reserva| !                  " );
         new Principal().setVisible(true);
         this.dispose();
   
         }else{            
         JOptionPane.showMessageDialog(null,"                       Login não cadastrado !                          " );
                   
         }
     
         } catch (SQLException e) {
   
         }
   
         
          new Principal().setVisible(true);
         this.dispose();  

    }