Question

我使用单独的DAO类进行登录和注册，如下所示：

注册DAO：

public class RegistrationDAO {

    public void insert(UserProfile user) {
        try {
            Connection con = DBConnection.getConnection();
            String query = "insert into TBL_USER (USR_FIRST_NAME,USR_LST_NAME,USR_PRIMARY_EMAIL,USR_PASSWORD) values(?,?,?,?)";
            PreparedStatement pst = con.prepareStatement(query);

            pst.setString(1, user.getFirstName());
            pst.setString(2, user.getLastName());
            pst.setString(3, user.getEmail());
            pst.setString(4, user.getPassword());
            pst.executeUpdate();
        } catch (Exception e) {
            System.out.println("@@@@Record insertion error in Registration DAO@@@@");
            e.printStackTrace();
        }
    }
}

登录DAO：

public class LoginDAO {

    public boolean authenticate(String email, String password)
            throws Exception {
        boolean isUser = false;
        try {
            Connection con = DBConnection.getConnection();
            PreparedStatement statement = con.prepareStatement("select USR_PRIMARY_EMAIL, USR_PASSWORD from TBL_USER where USR_PRIMARY_EMAIL=? and USR_PASSWORD=?");
            statement.setString(1, email);
            statement.setString(2, password);
            ResultSet result = statement.executeQuery();
            if (result.next()) {
                isUser = true;
                System.out.println("User authenticated successfully");
            } else {
                System.out.println("Invalid username or password!");
            }
        } catch (Exception e) {
            System.out.println("DB related Error");
            e.printStackTrace();
        }
        return isUser;
    }
}

让我们说如果将来我的数据库从oracle更改为mySql，那么我应该能够连接。我开始知道DAO工厂和DAO接口必须用于连接多个数据库，但我无法确定如何在我的情况下应用它。

我是否需要分别为RegistatrationDao和LoginDao提供两个DAO接口？有什么更好的方法来实现这个目标？

Answer 1

    public interface LoginDAO {
                    public boolean authenticate(String email, String password) throws Exception;
                }

    public class OracleLoginDAOImpl implements LoginDAO {
               public boolean authenticate(String email, String password) throws Exception {
                  //Oracle specific implementation goes here.
               }
        }

    public class MySqlLoginDAOImpl implements LoginDAO {
               public boolean authenticate(String email, String password) throws Exception {
                  //MySQL specific implementation goes here.
               }
        }

//NOW IN YOUR LOGIN Service
public class LoginService {
   private LoginDAO loginDAO = new OracleLoginDAOImpl ();
   //OR U CAN USE MYSQLDAO As BELOW
   //private LoginDAO loginDAO = new MySqlLoginDAOImpl();
    loginDAO.autheticate("user","password");
}

//同样为RegistrationDAO及其Oracle和MySQL实现类创建接口。

如何使用dao工厂模式登录和注册dao

1 个答案: