Assignment 4: Public constructor

Part 1 (0 points): Warm-up
As usual, do NOT submit this part, as it will not be graded.
Warm-up Question 1 (0 points) Write a class describing a Cat object. A cat has the following attributes: a name (String), a breed (String), an age (int) and a mood (String). The mood of a cat can be one of the following: sleepy, hungry, angry, happy, crazy. The cat constructor takes as input a String and sets that value to be the breed. The Cat class also contains a method called talk(). This method takes no input and returns nothing. Depending on the mood of the cat, it prints something different. If the cat’s mood is sleepy, it prints meow. If the mood is hungry, it prints RAWR!. If the cat is angry, it prints hsssss. If the cat is happy it prints purrrr. If the cat is crazy, it prints a String of 10 gibberish characters (e.g. raseagafqa).
The cat attributes are all private. Each one has a corresponding public method called getAttributeName() (ie: getName(), getMood(), etc.) which returns the value of the attribute. All but the breed also have a public method called setAttributeName() which takes as input a value of the type of the attribute and sets the attribute to that value. Be sure that only valid mood sets are permitted. (ie, a cat’s mood can only be one of five things). There is no setBreed() method because the breed of a cat is set at birth and cannot change.
Test your class in another file which contains only a main method. Test all methods to make sure they work as expected.
Warm-up Question 2 (0 points) Using the Cat type defined in the previous question, create a Cat[] of size 5. Create 5 Cat objects and put them all into the array. Then use a loop to have all the Cat objects meow.
Warm-up Question 3 (0 points) Write a class Vector. A Vector should consist of three private properties of type double: x, y, and z. You should add to your class a constructor which takes as input 3 doubles. These doubles should be assigned to x, y, and z. You should then write methods getX(), getY(), getZ(), setX(), setY(), and setZ() which allow you to get and set the values of the vector. Should this method be static or non-static?
Warm-up Question 4 (0 points) Add to your Vector class a method calculateMagnitude which returns a double representing the magnitude of the vector. Should this method be static or non-static? The magnitude can be computed by taking: magnitude =px2 + y2 + z2 Warm-up Question 5 (0 points) Write a method scalarMultiply which takes as input a double[], and a double scale, and returns void. The method should modify the input array by multiplying each value in the array by scale. Should this method be static or non-static?
Warm-up Question 6 (0 points) Write a method deleteElement which takes as input an int[] and an int target and deletes all occurrences of target from the array. By “delete” we mean create a new array (of smaller size) which has the same values as the old array but without any occurrences of target. The method should return the new int[]. Question to consider: Why is it that we have to return an array and can’t simply change the input parameter array like in the previous question? Should these methods be static or non-static?
Warm-up Question 7 (0 points) Write the same method, except this time it should take as input a String[] and a String. What is different about this than the previous method? (Hint: Remember that String is a reference type.)
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Part 2
The questions in this part of the assignment will be graded.
Question 1: Booking System (100 points) For this question, you will write several classes, and then create and use instances of those classes in order to simulate a hotel booking system. Note that in addition to the required methods below, you are free to add as many other private methods as you want (no additional public method is allowed).
(a) (20 points) Write a class Room. A Room has the following private attributes: • A String type • A double price • A boolean availability The Room class also contains the following public methods: • A constructor that takes as input the type of the room and uses it to initialize the attributes. Note that there are only 3 type of Rooms supported by the program: double, queen, and king. If the input is not one of these types, then the constructor should throw an IllegalArgumentException explaining that no room of such type can be created. The price of the room is based on its type as follows: $90 for a double, $110 for a queen, $150 for a king. The constructor should set the availability for a new room to be true. • getType which returns the type of the room. • getPrice which returns the price of the room. • getAvailability which returns the availability of the room. • changeAvailability which takes no input and sets the value stored in the availability attribute to be the opposite of the one currently there. • A findAvailableRoom method which takes as input an array of Rooms as well as a String indicating the room type. The method should return the first available room in the array of the indicated type. If no such room exists (either because all rooms of said type are occupied, or because no room of such type is in the array), the method returns null.
(b) (10 points) Write a class Reservation. A Reservation has the following private attributes: • A String name • A Room roomReserved The Reservation class also contains the following public methods: • A constructor that takes as input a Room and the name under which the reservation is made. The constructor must use its inputs to initialize the attributes. • getName which returns the name under which the reservation was made. • getRoom which returns the Room that has been reserved. (c) (40 points) Write a class Hotel. This class has three private attributes: • A String name • An array of Room • An array of Reservation It also has the following methods:
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• A public constructor that takes as input the name of the hotel, and an array of rooms. It initializes the Room array and copies the Room references from the input array to the Hotel array. • A private method addReservation that takes a Reservation as input and adds it to the array of Reservation of the hotel. • A private method removeReservation that takes as input a name and a type of room. If no reservation has been made under the given name for the given type of room, then the method should throw a NoSuchElementException with the appropriate message. If a matching reservation is found, then the method should remove such reservation from the array of reservations of the hotel, and make sure that the availability of the Room is modified accordingly. Note that you need to import java.util.NoSuchElementException in order to be able to use it. • A public method createReservation that takes as input a name and the type of the room that should be reserved. The method should use findAvailableRoom (from the Room class) to verify whether a room of the given type is available in the hotel. If not, the method should print a message informing the user that the hotel has no available rooms of the requested type. Otherwise, the method should: create a reservation for such room under the given name, change the availability of the room, and add the reservation to the array of reservations of the hotel using the addReservation method. In this case, the method should also print a message letting the user know that the reservation was successfully completed. • A public method cancelReservation that takes as input the name under which the reservation was made and the room type reserved. This method should use the removeReservation method to cancel the reservation. If no matching reservation was found, the method should inform the user that no reservation under such name has been made for the given type of room. Otherwise, the method should print a message letting the user know that the operation was successful. To receive full marks, a try/catch block should be used. • A public method printInvoice that takes as input a name and prints out a message letting the user know how much the given person owes the hotel based on all the reservations made under such name. • The toString method that returns a String containing the name of the hotel as well as how many available rooms of each type the hotel has.
(d) (30 points) In the provided class BookingSystem write a main method. Here, you will write a main method that creates an hotel where the name of the hotel is chosen by the user via a Scanner object. The program then creates an array of rooms at random and uses it, together with the hotel name, to create a new hotel.
In order to facilitate generating your Room array, we have provided methods to generate a random number of rooms, and to select the room types randomly from a provided array.
Then, the program should print on the screen a menu from which the user can chose one of the following options:
1. Make a reservation
2. Cancel a reservation
3. See an invoice
4. See the hotel info
5. Exit the booking system
Depending on the option chosen, you should use Scanner to obtain from the user the information needed (if any) to carry forward the operation selected. After each operation, the main menu should
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be displayed again, unless the user had chosen to exit the booking system. In such case, the program should end. If the user enters a wrong option, then the main menu should also be displayed again. Note that you can assume that the user will always be entering an integer. Sample interaction and output is shown below.
First example:
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Second example:
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What To Submit
Please put all your files in a folder called Assignment4 ID, where ‘ID’ should be replaced by your McGill ID number. Zip the folder (please DO NOT rar it) and submit it in MyCourses. Inside your zipped folder there must be the files listed below. Do not submit any other files, especially .class files.
BookingSystem.java Hotel.java Reservation.java Room.java Confession.txt (optional) In this file, you can tell the TA about any issues you ran into doing this assignment. If you point out an error that you know occurs in your problem, it may lead the TA to give you more partial credit. On the other hand, it also may lead the TA to notice something that otherwise they would not.