#1321 Added comments and refactored code

transaction-script/pom.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0"
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xmlns="http://maven.apache.org/POM/4.0.0"
          xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
     <parent>
         <artifactId>java-design-patterns</artifactId>
@@ -15,14 +15,14 @@
         <dependency>
             <groupId>com.h2database</groupId>
             <artifactId>h2</artifactId>
-            <version>1.4.200</version>
-            <scope>test</scope>
         </dependency>
+
         <dependency>
             <groupId>com.h2database</groupId>
             <artifactId>h2</artifactId>
+            <version>1.4.200</version>
+            <scope>test</scope>
         </dependency>
-
     </dependencies>
 
 </project>

transaction-script/src/main/java/com/ashishtrivedi16/transactionscript/Hotel.java

@@ -1,51 +1,66 @@
 package com.ashishtrivedi16.transactionscript;
 
-import com.ashishtrivedi16.transactionscript.db.HotelDAOImpl;
+import com.ashishtrivedi16.transactionscript.db.HotelDaoImpl;
+import java.util.Optional;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import java.util.Optional;
-
 public class Hotel {
-    private static final Logger LOGGER = LoggerFactory.getLogger(TransactionScriptApp.class);
+  private static final Logger LOGGER = LoggerFactory.getLogger(TransactionScriptApp.class);
 
-    private HotelDAOImpl hotelDAO;
+  private HotelDaoImpl hotelDao;
 
-    public Hotel(HotelDAOImpl hotelDAO) {
+  public Hotel(HotelDaoImpl hotelDao) {
-        this.hotelDAO = hotelDAO;
+    this.hotelDao = hotelDao;
+  }
+
+  /**
+   * Book a room.
+   *
+   * @param roomNumber room to book
+   * @throws Exception if any error
+   */
+  public void bookRoom(int roomNumber) throws Exception {
+
+    Optional<Room> room = hotelDao.getById(roomNumber);
+
+    if (room.isEmpty()) {
+      LOGGER.info(roomNumber + " does not exist");
+    } else {
+      if (room.get().isBooked()) {
+        LOGGER.info("Room already booked!");
+      } else {
+        Room updateRoomBooking = room.get();
+        updateRoomBooking.setBooked(true);
+        hotelDao.update(updateRoomBooking);
+      }
     }
+  }
 
-    public void bookRoom(int roomNumber) throws Exception {
+  /**
-        /*
+   * Cancel a room booking.
-            TODO
+   *
-                -> Check if room is available
+   * @param roomNumber room to cancel booking
-                -> Book the room
+   * @throws Exception if any error
-                -> Commit transaction
+   */
-        */
+  public void cancelRoomBooking(int roomNumber) throws Exception {
 
-        Optional<Room> room = hotelDAO.getById(roomNumber);
+    Optional<Room> room = hotelDao.getById(roomNumber);
 
-        if (!room.isPresent()) {
+    if (room.isEmpty()) {
-            LOGGER.info(roomNumber + " does not exist");
+      LOGGER.info("Room number: " + roomNumber + " does not exist");
-        } else {
+    } else {
-            if (room.get().isBooked()) {
+      if (room.get().isBooked()) {
-                LOGGER.info("Room already booked!");
+        Room updateRoomBooking = room.get();
-            } else {
+        updateRoomBooking.setBooked(false);
-                Room updateRoomBooking = room.get();
+        int refundAmount = updateRoomBooking.getPrice();
-                updateRoomBooking.setBooked(true);
+        hotelDao.update(updateRoomBooking);
-                hotelDAO.update(updateRoomBooking);
+
-            }
+        LOGGER.info("Booking cancelled for room number: " + roomNumber);
-        }
+        LOGGER.info(refundAmount + " is refunded");
-    }
+      } else {
-
+        LOGGER.info("No booking for the room exists");
-    public void cancelRoomBooking(int roomNumber) {
+      }
-        /*
-
-            TODO
-                -> Check if room is booked
-                -> Calculate refund price
-                -> Cancel the room booking
-                -> Commit transaction
-         */
     }
+  }
 }

transaction-script/src/main/java/com/ashishtrivedi16/transactionscript/Room.java

@@ -1,80 +1,100 @@
 package com.ashishtrivedi16.transactionscript;
 
+/**
+ * A room POJO that represents the data that will be read from the data source.
+ */
 public class Room {
 
-    private int id;
+  private int id;
-    private String roomType;
+  private String roomType;
-    private int price;
+  private int price;
-    private boolean booked;
+  private boolean booked;
 
-    public Room(int id, String roomType, int price, boolean booked) {
+  /**
-        this.id = id;
+   * Create an instance of room.
-        this.roomType = roomType;
+   * @param id room id
-        this.price = price;
+   * @param roomType room type
-        this.booked = booked;
+   * @param price room price
+   * @param booked room booking status
+   */
+  public Room(int id, String roomType, int price, boolean booked) {
+    this.id = id;
+    this.roomType = roomType;
+    this.price = price;
+    this.booked = booked;
+  }
+
+  public int getId() {
+    return id;
+  }
+
+  public void setId(int id) {
+    this.id = id;
+  }
+
+  public String getRoomType() {
+    return roomType;
+  }
+
+  public void setRoomType(String roomType) {
+    this.roomType = roomType;
+  }
+
+  public int getPrice() {
+    return price;
+  }
+
+  public void setPrice(int price) {
+    this.price = price;
+  }
+
+  public boolean isBooked() {
+    return booked;
+  }
+
+  public void setBooked(boolean booked) {
+    this.booked = booked;
+  }
+
+  @Override
+  public boolean equals(Object o) {
+    if (this == o) {
+      return true;
+    }
+    if (o == null || getClass() != o.getClass()) {
+      return false;
     }
 
-    public int getId() {
+    Room room = (Room) o;
-        return id;
+
+    if (id != room.id) {
+      return false;
     }
-
+    if (price != room.price) {
-    public void setId(int id) {
+      return false;
-        this.id = id;
     }
-
+    if (booked != room.booked) {
-    public String getRoomType() {
+      return false;
-        return roomType;
     }
+    return roomType.equals(room.roomType);
+  }
 
-    public void setRoomType(String roomType) {
+  @Override
-        this.roomType = roomType;
+  public int hashCode() {
-    }
+    int result = id;
+    result = 31 * result + roomType.hashCode();
+    result = 31 * result + price;
+    result = 31 * result + (booked ? 1 : 0);
+    return result;
+  }
 
-    public int getPrice() {
+  @Override
-        return price;
+  public String toString() {
-    }
+    return "Room{"
-
+        + "id=" + id
-    public void setPrice(int price) {
+        + ", roomType=" + roomType
-        this.price = price;
+        + ", price=" + price
-    }
+        + ", booked=" + booked
-
+        + '}';
-    public boolean isBooked() {
+  }
-        return booked;
-    }
-
-    public void setBooked(boolean booked) {
-        this.booked = booked;
-    }
-
-    @Override
-    public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
-
-        Room room = (Room) o;
-
-        if (id != room.id) return false;
-        if (price != room.price) return false;
-        if (booked != room.booked) return false;
-        return roomType == room.roomType;
-    }
-
-    @Override
-    public int hashCode() {
-        int result = id;
-        result = 31 * result + roomType.hashCode();
-        result = 31 * result + price;
-        result = 31 * result + (booked ? 1 : 0);
-        return result;
-    }
-
-    @Override
-    public String toString() {
-        return "Room{" +
-                "id=" + id +
-                ", roomType=" + roomType +
-                ", price=" + price +
-                ", booked=" + booked +
-                '}';
-    }
 }

transaction-script/src/main/java/com/ashishtrivedi16/transactionscript/TransactionScriptApp.java

@@ -1,13 +1,11 @@
 package com.ashishtrivedi16.transactionscript;
 
 import com.ashishtrivedi16.transactionscript.db.CustomException;
-import com.ashishtrivedi16.transactionscript.db.HotelDAOImpl;
+import com.ashishtrivedi16.transactionscript.db.HotelDaoImpl;
 import com.ashishtrivedi16.transactionscript.db.RoomSchemaSql;
-
 import java.sql.SQLException;
 import java.util.List;
 import javax.sql.DataSource;
-
 import org.h2.jdbc.JdbcSQLException;
 import org.h2.jdbcx.JdbcDataSource;
 import org.slf4j.Logger;
@@ -15,76 +13,96 @@ import org.slf4j.LoggerFactory;
 
 public class TransactionScriptApp {
 
-    private static final String H2_DB_URL = "jdbc:h2:~/test";
+  private static final String H2_DB_URL = "jdbc:h2:~/test";
-    private static final Logger LOGGER = LoggerFactory.getLogger(TransactionScriptApp.class);
+  private static final Logger LOGGER = LoggerFactory.getLogger(TransactionScriptApp.class);
-    private static final String ALL_ROOMS = "customerDao.getAllRooms(): ";
+  private static final String ALL_ROOMS = "customerDao.getAllRooms(): ";
 
-    public static void main(String[] args) throws Exception {
+  /**
+   * Program entry point.
+   *
+   * @param args command line arguments
+   * @throws Exception if any error occurs
+   */
+  public static void main(String[] args) throws Exception {
 
-        /*
+    final var dataSource = createDataSource();
-            TODO
+    deleteSchema(dataSource);
-                -> Create in memory database and some sample tables for demo
+    createSchema(dataSource);
-        */
+    final var dao = new HotelDaoImpl(dataSource);
-        final var dataSource = createDataSource();
+    addRooms(dao);
-        createSchema(dataSource);
-        final var DAO = new HotelDAOImpl(dataSource);
 
-        addRooms(DAO);
+    getRoomStatus(dao);
-        try (var customerStream = DAO.getAll()) {
-            customerStream.forEach((customer) -> LOGGER.info(customer.toString()));
-        }
 
-        Hotel hotel = new Hotel(DAO);
+    Hotel hotel = new Hotel(dao);
 
-        hotel.bookRoom(1);
+    hotel.bookRoom(1);
-        hotel.bookRoom(2);
+    hotel.bookRoom(2);
-        hotel.bookRoom(3);
+    hotel.bookRoom(3);
-        hotel.bookRoom(4);
+    hotel.bookRoom(4);
-        hotel.bookRoom(5);
+    hotel.bookRoom(5);
-        hotel.bookRoom(6);
+    hotel.bookRoom(6);
 
-        hotel.cancelRoomBooking(3);
+    hotel.cancelRoomBooking(1);
-        hotel.cancelRoomBooking(4);
+    hotel.cancelRoomBooking(3);
+    hotel.cancelRoomBooking(5);
 
-        deleteSchema(dataSource);
+    getRoomStatus(dao);
 
+    deleteSchema(dataSource);
+
+  }
+
+  private static void getRoomStatus(HotelDaoImpl dao) throws Exception {
+    try (var customerStream = dao.getAll()) {
+      customerStream.forEach((customer) -> LOGGER.info(customer.toString()));
     }
+  }
 
-    private static void deleteSchema(DataSource dataSource) throws SQLException {
+  private static void deleteSchema(DataSource dataSource) throws SQLException {
-        try (var connection = dataSource.getConnection();
+    try (var connection = dataSource.getConnection();
-             var statement = connection.createStatement()) {
+         var statement = connection.createStatement()) {
-            statement.execute(RoomSchemaSql.DELETE_SCHEMA_SQL);
+      statement.execute(RoomSchemaSql.DELETE_SCHEMA_SQL);
-        }
     }
+  }
 
-    private static void createSchema(DataSource dataSource) throws Exception {
+  private static void createSchema(DataSource dataSource) throws Exception {
-        try (var connection = dataSource.getConnection();
+    try (var connection = dataSource.getConnection();
-             var statement = connection.createStatement()) {
+         var statement = connection.createStatement()) {
-            statement.execute(RoomSchemaSql.CREATE_SCHEMA_SQL);
+      statement.execute(RoomSchemaSql.CREATE_SCHEMA_SQL);
-        } catch (JdbcSQLException e) {
+    } catch (JdbcSQLException e) {
-            throw new CustomException(e.getMessage(), e);
+      throw new CustomException(e.getMessage(), e);
-        }
     }
+  }
 
-    public static DataSource createDataSource() {
+  /**
-        JdbcDataSource dataSource = new JdbcDataSource();
+   * Get database.
-        dataSource.setUrl(H2_DB_URL);
+   *
-        return dataSource;
+   * @return h2 datasource
-    }
+   */
+  public static DataSource createDataSource() {
+    JdbcDataSource dataSource = new JdbcDataSource();
+    dataSource.setUrl(H2_DB_URL);
+    return dataSource;
+  }
 
-    private static void addRooms(HotelDAOImpl hotelDAO) throws Exception {
+  private static void addRooms(HotelDaoImpl hotelDao) throws Exception {
-        for (var room : generateSampleRooms()) {
+    for (var room : generateSampleRooms()) {
-            hotelDAO.add(room);
+      hotelDao.add(room);
-        }
     }
+  }
 
-    public static List<Room> generateSampleRooms() {
+  /**
-        final var room1 = new Room(1, "Single", 50, false);
+   * Generate rooms.
-        final var room2 = new Room(2, "Double", 80, false);
+   *
-        final var room3 = new Room(3, "Queen", 120, false);
+   * @return list of rooms
-        final var room4 = new Room(4, "King", 150, false);
+   */
-        final var room5 = new Room(5, "Single", 50, false);
+  public static List<Room> generateSampleRooms() {
-        final var room6 = new Room(6, "Double", 80, false);
+    final var room1 = new Room(1, "Single", 50, false);
-        return List.of(room1, room2, room3, room4, room5, room6);
+    final var room2 = new Room(2, "Double", 80, false);
-    }
+    final var room3 = new Room(3, "Queen", 120, false);
+    final var room4 = new Room(4, "King", 150, false);
+    final var room5 = new Room(5, "Single", 50, false);
+    final var room6 = new Room(6, "Double", 80, false);
+    return List.of(room1, room2, room3, room4, room5, room6);
+  }
 }

transaction-script/src/main/java/com/ashishtrivedi16/transactionscript/db/HotelDAO.java

@@ -1,19 +0,0 @@
-package com.ashishtrivedi16.transactionscript.db;
-
-import com.ashishtrivedi16.transactionscript.Room;
-
-import java.util.Optional;
-import java.util.stream.Stream;
-
-public interface HotelDAO {
-
-    public Stream<Room> getAll() throws Exception;
-
-    public Optional<Room> getById(int id) throws Exception;
-
-    public Boolean add(Room room) throws Exception;
-
-    public Boolean update(Room room) throws Exception;
-
-    public Boolean delete(Room room) throws Exception;
-}

transaction-script/src/main/java/com/ashishtrivedi16/transactionscript/db/HotelDAOImpl.java

@@ -1,147 +0,0 @@
-package com.ashishtrivedi16.transactionscript.db;
-
-import com.ashishtrivedi16.transactionscript.Room;
-
-import javax.sql.DataSource;
-import java.sql.Connection;
-import java.sql.PreparedStatement;
-import java.sql.ResultSet;
-import java.sql.SQLException;
-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;
-
-public class HotelDAOImpl implements HotelDAO {
-
-    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");
-            ResultSet 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 (SQLException e) {
-                        throw new RuntimeException(e); // NOSONAR
-                    }
-                }
-            }, false).onClose(() -> {
-                try {
-                    mutedClose(connection, statement, resultSet);
-                } catch (Exception e) {
-                    e.printStackTrace();
-                }
-            });
-        } catch (SQLException e) {
-            throw new CustomException(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 (SQLException ex) {
-            throw new CustomException(ex.getMessage(), ex);
-        } 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 (SQLException ex) {
-            throw new CustomException(ex.getMessage(), ex);
-        }
-    }
-
-    @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.setInt(1, room.getId());
-            statement.setString(2, room.getRoomType());
-            statement.setBoolean(3, room.isBooked());
-            statement.setInt(4, room.getId());
-            return statement.executeUpdate() > 0;
-        } catch (SQLException ex) {
-            throw new CustomException(ex.getMessage(), ex);
-        }
-    }
-
-    @Override
-    public Boolean delete(Room room) throws Exception {
-        try (var connection = getConnection();
-             var statement = connection.prepareStatement("DELETE FROM CUSTOMERS WHERE ID = ?")) {
-            statement.setInt(1, room.getId());
-            return statement.executeUpdate() > 0;
-        } catch (SQLException ex) {
-            throw new CustomException(ex.getMessage(), ex);
-        }
-    }
-
-    private Connection getConnection() throws SQLException {
-        return dataSource.getConnection();
-    }
-
-    private void mutedClose(Connection connection, PreparedStatement statement, ResultSet resultSet) throws Exception {
-        try {
-            resultSet.close();
-            statement.close();
-            connection.close();
-        } catch (SQLException e) {
-            throw new CustomException(e.getMessage(), e);
-        }
-    }
-
-    private Room createRoom(ResultSet resultSet) throws SQLException {
-        return new Room(resultSet.getInt("ID"),
-                resultSet.getString("ROOM_TYPE"),
-                resultSet.getInt("PRICE"),
-                resultSet.getBoolean("BOOKED"));
-    }
-}

transaction-script/src/main/java/com/ashishtrivedi16/transactionscript/db/HotelDao.java

@@ -0,0 +1,19 @@
+package com.ashishtrivedi16.transactionscript.db;
+
+import com.ashishtrivedi16.transactionscript.Room;
+
+import java.util.Optional;
+import java.util.stream.Stream;
+
+public interface HotelDao {
+
+  Stream<Room> getAll() throws Exception;
+
+  Optional<Room> getById(int id) throws Exception;
+
+  Boolean add(Room room) throws Exception;
+
+  Boolean update(Room room) throws Exception;
+
+  Boolean delete(Room room) throws Exception;
+}

transaction-script/src/main/java/com/ashishtrivedi16/transactionscript/db/HotelDaoImpl.java

@@ -0,0 +1,148 @@
+package com.ashishtrivedi16.transactionscript.db;
+
+import com.ashishtrivedi16.transactionscript.Room;
+import java.sql.Connection;
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+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;
+
+public class HotelDaoImpl implements HotelDao {
+
+  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");
+      ResultSet 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 (SQLException e) {
+            throw new RuntimeException(e); // NOSONAR
+          }
+        }
+      }, false).onClose(() -> {
+        try {
+          mutedClose(connection, statement, resultSet);
+        } catch (Exception e) {
+          e.printStackTrace();
+        }
+      });
+    } catch (SQLException e) {
+      throw new CustomException(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 (SQLException ex) {
+      throw new CustomException(ex.getMessage(), ex);
+    } 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 (SQLException ex) {
+      throw new CustomException(ex.getMessage(), ex);
+    }
+  }
+
+  @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 (SQLException ex) {
+      throw new CustomException(ex.getMessage(), ex);
+    }
+  }
+
+  @Override
+  public Boolean delete(Room room) throws Exception {
+    try (var connection = getConnection();
+         var statement = connection.prepareStatement("DELETE FROM CUSTOMERS WHERE ID = ?")) {
+      statement.setInt(1, room.getId());
+      return statement.executeUpdate() > 0;
+    } catch (SQLException ex) {
+      throw new CustomException(ex.getMessage(), ex);
+    }
+  }
+
+  private Connection getConnection() throws SQLException {
+    return dataSource.getConnection();
+  }
+
+  private void mutedClose(Connection connection, PreparedStatement statement, ResultSet resultSet)
+      throws Exception {
+    try {
+      resultSet.close();
+      statement.close();
+      connection.close();
+    } catch (SQLException e) {
+      throw new CustomException(e.getMessage(), e);
+    }
+  }
+
+  private Room createRoom(ResultSet resultSet) throws SQLException {
+    return new Room(resultSet.getInt("ID"),
+        resultSet.getString("ROOM_TYPE"),
+        resultSet.getInt("PRICE"),
+        resultSet.getBoolean("BOOKED"));
+  }
+}

transaction-script/src/main/java/com/ashishtrivedi16/transactionscript/db/RoomSchemaSql.java

@@ -28,12 +28,11 @@ package com.ashishtrivedi16.transactionscript.db;
  */
 public final class RoomSchemaSql {
 
+  public static final String CREATE_SCHEMA_SQL =
+      "CREATE TABLE ROOMS (ID NUMBER, ROOM_TYPE VARCHAR(100), PRICE INT(100), BOOKED VARCHAR(100))";
+  public static final String DELETE_SCHEMA_SQL = "DROP TABLE ROOMS IF EXISTS";
+
   private RoomSchemaSql() {
   }
 
-  public static final String CREATE_SCHEMA_SQL =
-      "CREATE TABLE ROOMS (ID NUMBER, ROOM_TYPE VARCHAR(100), PRICE INT(100), BOOKED VARCHAR(100))";
-
-  public static final String DELETE_SCHEMA_SQL = "DROP TABLE ROOMS";
-
 }