import model.UserDtoModel;
import model.UserLocalModel;

import java.sql.*;
import java.util.ArrayList;
import java.util.List;

public class DatabaseHandler implements DatabseQueries {

    private Connection connection;

    private Boolean checkIfJdbcDriverIsActive() {
        String driver = "com.mysql.jdbc.Driver";
        try {
            Class.forName(driver);
            return true;
        } catch (Exception ex) {
            System.out.println("Database driver not found");
        }
        return false;
    }

    public void openConnection(String dbUrl, String userName, String password) {
        checkIfJdbcDriverIsActive();
        try {
            connection = DriverManager.getConnection(dbUrl, userName, password);
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

    @Override
    public List<UserLocalModel> selectAllUsers(String executeQuery2) throws SQLException {
        String db_url = "jdbc:mysql://mysql.agh.edu.pl:3306/bachniak";
        String userName = "bachniak";
        String password = "kHRSkY8bZjKjzhan";
//        openConnection(db_url, userName, password);

        Connection connection = null;
        try {
            connection = DriverManager.getConnection(db_url, userName, password);
            System.out.println("Connected :D");
        } catch (SQLException e) {
            e.printStackTrace();
            System.out.println("Kurwa error");
        }

        String executeQuery = "SELECT * FROM Krzysztof";
        Statement statement = connection.createStatement();
        ResultSet resultSet = statement.executeQuery(executeQuery);
        List<UserLocalModel> usersList = new ArrayList();
        UserDtoModel dtoModel = new UserDtoModel(0, "", "");

        while (resultSet.next()) {
            dtoModel.setId(resultSet.getInt("id"));
            dtoModel.setFirstName(resultSet.getString("first_name"));
            dtoModel.setLastName(resultSet.getString("last_name"));
            usersList.add(new UserLocalModel(dtoModel.getId(), dtoModel.getFirstName(), dtoModel.getLastName()));
            System.out.println(dtoModel.getId().toString() + " " + dtoModel.getFirstName() + "" + dtoModel.getLastName());
        }
        return usersList;
    }

    @Override
    public void insert(UserDtoModel model) {

    }

    @Override
    public void remove(UserDtoModel model) {

    }
}


.......................


package model;

public class UserLocalModel {

    private Integer id;
    private String firstName;
    private String lastName;

    public UserLocalModel(Integer id, String firstName, String lastName) {
        this.id = id;
        this.firstName = firstName;
        this.lastName = lastName;
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getFirstName() {
        return firstName;
    }

    public void setFirstName(String firstName) {
        this.firstName = firstName;
    }

    public String getLastName() {
        return lastName;
    }

    public void setLastName(String lastName) {
        this.lastName = lastName;
    }
}



..................


import model.UserDtoModel;
import model.UserLocalModel;

import java.sql.SQLException;
import java.util.List;

public interface DatabseQueries {
    List<UserLocalModel> selectAllUsers(String executeQuery) throws SQLException;
    void insert(UserDtoModel model);
    void remove(UserDtoModel model);
}

....

import java.sql.SQLException;

public class Main {


    public static void main(String[] args) {
        String db_url = "jdbc:mysql://mysql.agh.edu.pl:3306/bachniak";
        String userName = "Krzysztof";
        String password = "kHRSkY8bZjKjzhan";
        DatabaseHandler databaseHandler = new DatabaseHandler();
//        databaseHandler.openConnection(db_url, userName, password);
        try {
            databaseHandler.selectAllUsers("");
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

}