[Java/Servlet] MVC 기반으로 방 계약 구현

Booking 테이블은 다음과 같다

CREATE TABLE booking(
id BIGINT AUTO_INCREMENT PRIMARY KEY,
guest_id BIGINT NOT NULL,
room_id BIGINT NOT NULL,
check_in_date DATE NOT NULL,
check_out_date DATE NOT NULL,
booking_status INT NOT NULL,
FOREIGN KEY (guest_id) REFERENCES member(id),
FOREIGN KEY (room_id) REFERENCES room(id)
);

1. 모델 (Model)

모델은 데이터와 비즈니스 로직을 관리하는 부분입니다. 주로 데이터베이스와의 상호작용을 담당하는 DAO(Data Access Object) 클래스와 데이터 객체인 Entity 클래스를 포함합니다.

Booking 클래스 (Entity)

package com.example.model;

import java.time.LocalDate;

public class Booking {
    private long id;
    private long guestId;
    private long roomId;
    private LocalDate checkInDate;
    private LocalDate checkOutDate;
    private int bookingStatus;

    // 생성자, getter, setter 등 필요한 메서드 구현

    public Booking() {
    }

    public Booking(long guestId, long roomId, LocalDate checkInDate, LocalDate checkOutDate, int bookingStatus) {
        this.guestId = guestId;
        this.roomId = roomId;
        this.checkInDate = checkInDate;
        this.checkOutDate = checkOutDate;
        this.bookingStatus = bookingStatus;
    }

    // Getter and Setter methods

    public long getId() {
        return id;
    }

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

    public long getGuestId() {
        return guestId;
    }

    public void setGuestId(long guestId) {
        this.guestId = guestId;
    }

    public long getRoomId() {
        return roomId;
    }

    public void setRoomId(long roomId) {
        this.roomId = roomId;
    }

    public LocalDate getCheckInDate() {
        return checkInDate;
    }

    public void setCheckInDate(LocalDate checkInDate) {
        this.checkInDate = checkInDate;
    }

    public LocalDate getCheckOutDate() {
        return checkOutDate;
    }

    public void setCheckOutDate(LocalDate checkOutDate) {
        this.checkOutDate = checkOutDate;
    }

    public int getBookingStatus() {
        return bookingStatus;
    }

    public void setBookingStatus(int bookingStatus) {
        this.bookingStatus = bookingStatus;
    }

    @Override
    public String toString() {
        return "Booking{" +
                "id=" + id +
                ", guestId=" + guestId +
                ", roomId=" + roomId +
                ", checkInDate=" + checkInDate +
                ", checkOutDate=" + checkOutDate +
                ", bookingStatus=" + bookingStatus +
                '}';
    }
}

BookingDAO 클래스

package com.example.dao;

import com.example.model.Booking;
import com.example.util.DBUtil;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class BookingDAO {

    // 예약 생성(host페이지에서 사용할듯)
    public void createBooking(Booking booking) { 
        Connection conn = null;
        PreparedStatement stmt = null;

        try {
            conn = DBUtil.getConnection();
            String sql = "INSERT INTO booking (guest_id, room_id, check_in_date, check_out_date, booking_status) VALUES (?, ?, ?, ?, ?)";
            stmt = conn.prepareStatement(sql);
            stmt.setLong(1, booking.getGuestId());
            stmt.setLong(2, booking.getRoomId());
            stmt.setObject(3, booking.getCheckInDate());
            stmt.setObject(4, booking.getCheckOutDate());
            stmt.setInt(5, booking.getBookingStatus());
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(stmt);
            DBUtil.close(conn);
        }
    }

    // 예약 상태 업데이트
    public void updateBookingStatus(long bookingId, int bookingStatus) {
        Connection conn = null;
        PreparedStatement stmt = null;

        try {
            conn = DBUtil.getConnection();
            String sql = "UPDATE booking SET booking_status = ? WHERE id = ?";
            stmt = conn.prepareStatement(sql);
            stmt.setInt(1, bookingStatus);
            stmt.setLong(2, bookingId);
            stmt.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(stmt);
            DBUtil.close(conn);
        }
    }

    // 모든 예약 조회
    public List<Booking> getAllBookings() {
        List<Booking> bookings = new ArrayList<>();
        Connection conn = null;
        PreparedStatement stmt = null;
        ResultSet rs = null;

        try {
            conn = DBUtil.getConnection();
            String sql = "SELECT * FROM booking";
            stmt = conn.prepareStatement(sql);
            rs = stmt.executeQuery();

            while (rs.next()) {
                Booking booking = new Booking();
                booking.setId(rs.getLong("id"));
                booking.setGuestId(rs.getLong("guest_id"));
                booking.setRoomId(rs.getLong("room_id"));
                booking.setCheckInDate(rs.getObject("check_in_date", LocalDate.class));
                booking.setCheckOutDate(rs.getObject("check_out_date", LocalDate.class));
                booking.setBookingStatus(rs.getInt("booking_status"));
                bookings.add(booking);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            DBUtil.close(rs);
            DBUtil.close(stmt);
            DBUtil.close(conn);
        }

        return bookings;
    }
}

2. 뷰 (View)

뷰는 사용자 인터페이스를 표시하는 부분입니다. 예를 들어, JSP 페이지를 사용하여 예약 관리 화면을 구성할 수 있습니다.

bookingManagement.jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8" %>
<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>Booking Management</title>
</head>
<body>
    <h1>Booking Management</h1>
    
    <table border="1">
        <tr>
            <th>ID</th>
            <th>Guest ID</th>
            <th>Room ID</th>
            <th>Check-in Date</th>
            <th>Check-out Date</th>
            <th>Status</th>
            <th>Action</th>
        </tr>
        <c:forEach var="booking" items="${bookings}">
            <tr>
                <td>${booking.id}</td>
                <td>${booking.guestId}</td>
                <td>${booking.roomId}</td>
                <td>${booking.checkInDate}</td>
                <td>${booking.checkOutDate}</td>
                <td>${booking.bookingStatus}</td>
                <td>
                    <form action="BookingController" method="post">
                        <input type="hidden" name="bookingId" value="${booking.id}">
                        <button type="submit" name="action" value="approve">Approve</button>
                        <button type="submit" name="action" value="reject">Reject</button>
                    </form>
                </td>
            </tr>
        </c:forEach>
    </table>
</body>
</html>

3. 컨트롤러 (Controller)

컨트롤러는 사용자 입력을 처리하고, 비즈니스 로직을 호출하며, 적절한 뷰를 표시하는 역할을 합니다.

BookingController 클래스

package com.example.controller;

import com.example.dao.BookingDAO;
import com.example.model.Booking;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.List;

@WebServlet("/BookingController")
public class BookingController extends HttpServlet {

    private BookingDAO bookingDAO;

    @Override
    public void init() throws ServletException {
        super.init();
        bookingDAO = new BookingDAO(); // DAO 초기화
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        String action = request.getParameter("action");
        long bookingId = Long.parseLong(request.getParameter("bookingId"));

        if ("approve".equals(action)) {
            bookingDAO.updateBookingStatus(bookingId, 1); // 승인 처리
        } else if ("reject".equals(action)) {
            bookingDAO.updateBookingStatus(bookingId, 2); // 거절 처리
        }

        // 예약 관리 페이지로 리다이렉트
        response.sendRedirect(request.getContextPath() + "/bookingManagement.jsp");
    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        List<Booking> bookings = bookingDAO.getAllBookings();
        request.setAttribute("bookings", bookings);
        request.getRequestDispatcher("/bookingManagement.jsp").forward(request, response);
    }
}

요약

위 예제에서는 MVC 모델을 사용하여 Booking 관련 기능을 구현하는 방법을 보여주었습니다. Booking 클래스를 Entity로 사용하여 데이터베이스와의 상호작용을 담당하는 BookingDAO 클래스를 구현하고, BookingController를 통해 사용자 입력을 처리하며 적절한