#1321 Added comments about TS

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

@@ -29,6 +29,20 @@ import org.h2.jdbcx.JdbcDataSource;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+/**
+ * Transaction Script (TS) is one of the simplest domain logic pattern.
+ * It needs less work to implement than other domain logic patterns and therefore
+ * it’s perfect fit for smaller applications that don't need big architecture behind them.
+ *
+ * <p>In this example we will use the TS pattern to implement booking and cancellation
+ * methods for a Hotel management App. The main method will initialise an instance of
+ * {@link Hotel} and add rooms to it. After that it will book and cancel a couple of rooms
+ * and that will be printed by the logger.</p>
+ *
+ * <p>The thing we have to note here is that all the operations related to booking or cancelling
+ * a room like checking the database if the room exists, checking the booking status or the
+ * room, calculating refund price are all clubbed inside a single transaction script method.</p>
+ */
 public class App {
 
   private static final String H2_DB_URL = "jdbc:h2:~/test";
@@ -36,7 +50,8 @@ public class App {
 
   /**
    * Program entry point.
-   *
+   * Initialises an instance of Hotel and adds rooms to it.
+   * Carries out booking and cancel booking transactions.
    * @param args command line arguments
    * @throws Exception if any error occurs
    */
@@ -47,12 +62,15 @@ public class App {
     createSchema(dataSource);
     final var dao = new HotelDaoImpl(dataSource);
 
+    // Add rooms
     addRooms(dao);
 
+    // Print room booking status
     getRoomStatus(dao);
   
     var hotel = new Hotel(dao);
 
+    // Book rooms
     hotel.bookRoom(1);
     hotel.bookRoom(2);
     hotel.bookRoom(3);
@@ -60,6 +78,7 @@ public class App {
     hotel.bookRoom(5);
     hotel.bookRoom(6);
 
+    // Cancel booking for a few rooms
     hotel.cancelRoomBooking(1);
     hotel.cancelRoomBooking(3);
     hotel.cancelRoomBooking(5);