146 lines
4.9 KiB
Java
146 lines
4.9 KiB
Java
/*
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* The MIT License
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* Copyright © 2014-2021 Ilkka Seppälä
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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package com.iluwatar.transactionscript;
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import java.util.List;
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import javax.sql.DataSource;
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import org.h2.jdbcx.JdbcDataSource;
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import org.slf4j.Logger;
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import org.slf4j.LoggerFactory;
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/**
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* Transaction Script (TS) is one of the simplest domain logic pattern.
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* It needs less work to implement than other domain logic patterns and therefore
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* it’s perfect fit for smaller applications that don't need big architecture behind them.
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*
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* <p>In this example we will use the TS pattern to implement booking and cancellation
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* methods for a Hotel management App. The main method will initialise an instance of
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* {@link Hotel} and add rooms to it. After that it will book and cancel a couple of rooms
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* and that will be printed by the logger.</p>
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*
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* <p>The thing we have to note here is that all the operations related to booking or cancelling
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* a room like checking the database if the room exists, checking the booking status or the
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* room, calculating refund price are all clubbed inside a single transaction script method.</p>
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*/
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public class App {
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private static final String H2_DB_URL = "jdbc:h2:~/test";
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private static final Logger LOGGER = LoggerFactory.getLogger(App.class);
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/**
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* Program entry point.
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* Initialises an instance of Hotel and adds rooms to it.
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* Carries out booking and cancel booking transactions.
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* @param args command line arguments
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* @throws Exception if any error occurs
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*/
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public static void main(String[] args) throws Exception {
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final var dataSource = createDataSource();
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deleteSchema(dataSource);
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createSchema(dataSource);
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final var dao = new HotelDaoImpl(dataSource);
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// Add rooms
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addRooms(dao);
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// Print room booking status
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getRoomStatus(dao);
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var hotel = new Hotel(dao);
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// Book rooms
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hotel.bookRoom(1);
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hotel.bookRoom(2);
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hotel.bookRoom(3);
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hotel.bookRoom(4);
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hotel.bookRoom(5);
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hotel.bookRoom(6);
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// Cancel booking for a few rooms
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hotel.cancelRoomBooking(1);
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hotel.cancelRoomBooking(3);
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hotel.cancelRoomBooking(5);
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getRoomStatus(dao);
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deleteSchema(dataSource);
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}
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private static void getRoomStatus(HotelDaoImpl dao) throws Exception {
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try (var customerStream = dao.getAll()) {
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customerStream.forEach((customer) -> LOGGER.info(customer.toString()));
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}
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}
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private static void deleteSchema(DataSource dataSource) throws java.sql.SQLException {
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try (var connection = dataSource.getConnection();
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var statement = connection.createStatement()) {
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statement.execute(RoomSchemaSql.DELETE_SCHEMA_SQL);
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}
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}
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private static void createSchema(DataSource dataSource) throws Exception {
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try (var connection = dataSource.getConnection();
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var statement = connection.createStatement()) {
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statement.execute(RoomSchemaSql.CREATE_SCHEMA_SQL);
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} catch (Exception e) {
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throw new Exception(e.getMessage(), e);
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}
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}
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/**
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* Get database.
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*
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* @return h2 datasource
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*/
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private static DataSource createDataSource() {
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var dataSource = new JdbcDataSource();
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dataSource.setUrl(H2_DB_URL);
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return dataSource;
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}
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private static void addRooms(HotelDaoImpl hotelDao) throws Exception {
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for (var room : generateSampleRooms()) {
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hotelDao.add(room);
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}
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}
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/**
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* Generate rooms.
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*
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* @return list of rooms
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*/
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private static List<Room> generateSampleRooms() {
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final var room1 = new Room(1, "Single", 50, false);
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final var room2 = new Room(2, "Double", 80, false);
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final var room3 = new Room(3, "Queen", 120, false);
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final var room4 = new Room(4, "King", 150, false);
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final var room5 = new Room(5, "Single", 50, false);
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final var room6 = new Room(6, "Double", 80, false);
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return List.of(room1, room2, room3, room4, room5, room6);
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}
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}
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