java-design-patterns/transaction-script/src/main/java/com/iluwatar/transactionscript/HotelDaoImpl.java

/*
 * The MIT License
 * Copyright © 2014-2019 Ilkka Seppälä
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

package com.iluwatar.transactionscript;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.Optional;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.function.Consumer;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
import javax.sql.DataSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class HotelDaoImpl implements HotelDao {
  private static final Logger LOGGER = LoggerFactory.getLogger(App.class);

  private final DataSource dataSource;

  public HotelDaoImpl(DataSource dataSource) {
    this.dataSource = dataSource;
  }

  @Override
  public Stream<Room> getAll() throws Exception {
    try {
      var connection = getConnection();
      var statement = connection.prepareStatement("SELECT * FROM ROOMS");
      var resultSet = statement.executeQuery(); // NOSONAR
      return StreamSupport.stream(new Spliterators.AbstractSpliterator<Room>(Long.MAX_VALUE,
          Spliterator.ORDERED) {

        @Override
        public boolean tryAdvance(Consumer<? super Room> action) {
          try {
            if (!resultSet.next()) {
              return false;
            }
            action.accept(createRoom(resultSet));
            return true;
          } catch (Exception e) {
            throw new RuntimeException(e); // NOSONAR
          }
        }
      }, false).onClose(() -> {
        try {
          mutedClose(connection, statement, resultSet);
        } catch (Exception e) {
          LOGGER.error(e.getMessage());
        }
      });
    } catch (Exception e) {
      throw new Exception(e.getMessage(), e);
    }
  }

  @Override
  public Optional<Room> getById(int id) throws Exception {
    ResultSet resultSet = null;

    try (var connection = getConnection();
         var statement = connection.prepareStatement("SELECT * FROM ROOMS WHERE ID = ?")) {

      statement.setInt(1, id);
      resultSet = statement.executeQuery();
      if (resultSet.next()) {
        return Optional.of(createRoom(resultSet));
      } else {
        return Optional.empty();
      }
    } catch (Exception e) {
      throw new Exception(e.getMessage(), e);
    } finally {
      if (resultSet != null) {
        resultSet.close();
      }
    }
  }

  @Override
  public Boolean add(Room room) throws Exception {
    if (getById(room.getId()).isPresent()) {
      return false;
    }

    try (var connection = getConnection();
         var statement = connection.prepareStatement("INSERT INTO ROOMS VALUES (?,?,?,?)")) {
      statement.setInt(1, room.getId());
      statement.setString(2, room.getRoomType());
      statement.setInt(3, room.getPrice());
      statement.setBoolean(4, room.isBooked());
      statement.execute();
      return true;
    } catch (Exception e) {
      throw new Exception(e.getMessage(), e);
    }
  }

  @Override
  public Boolean update(Room room) throws Exception {
    try (var connection = getConnection();
         var statement =
             connection
                 .prepareStatement("UPDATE ROOMS SET ROOM_TYPE = ?, PRICE = ?, BOOKED = ?"
                     + " WHERE ID = ?")) {
      statement.setString(1, room.getRoomType());
      statement.setInt(2, room.getPrice());
      statement.setBoolean(3, room.isBooked());
      statement.setInt(4, room.getId());
      return statement.executeUpdate() > 0;
    } catch (Exception e) {
      throw new Exception(e.getMessage(), e);
    }
  }

  @Override
  public Boolean delete(Room room) throws Exception {
    try (var connection = getConnection();
         var statement = connection.prepareStatement("DELETE FROM ROOMS WHERE ID = ?")) {
      statement.setInt(1, room.getId());
      return statement.executeUpdate() > 0;
    } catch (Exception e) {
      throw new Exception(e.getMessage(), e);
    }
  }

  private Connection getConnection() throws Exception {
    return dataSource.getConnection();
  }

  private void mutedClose(Connection connection, PreparedStatement statement, ResultSet resultSet)
      throws Exception {
    try {
      resultSet.close();
      statement.close();
      connection.close();
    } catch (Exception e) {
      throw new Exception(e.getMessage(), e);
    }
  }

  private Room createRoom(ResultSet resultSet) throws Exception {
    return new Room(resultSet.getInt("ID"),
        resultSet.getString("ROOM_TYPE"),
        resultSet.getInt("PRICE"),
        resultSet.getBoolean("BOOKED"));
  }
}