UserDAO

package com.socialka.model.user;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

import com.socialka.db.DBConnection;

public class UserDAO implements IUserDAO{
    private Connection connection;

    public UserDAO() throws Exception {
        this.connection = DBConnection.getInstance().getConnection();
    }

    @Override
    public int login(User user) throws UserException {
        try {
            Statement statement = this.connection.createStatement();
            ResultSet resultSet =  statement.executeQuery(
                    String.format("select count(*) from users where username = %s and password = %s);",
                        user.getUsername(), user.getPassword()));

            if (resultSet.next()) {
                return resultSet.getInt("id");
            }

            throw new UserException("Invalid user name or password");

        } catch (SQLException e) {
            e.printStackTrace();
            throw new UserException("DB is not working", e);
        }

    }

    @Override
    public void register() {

    }

    public static void main(String[] args) throws Exception {
        UserDAO dao = new UserDAO();
        int id = dao.login(new User("Guluba", "3333"));

        System.out.println(id);

    }

}