Question

This is the Java Object-oriend project. Please show the detail code and comment for each class. Thank you

Create a class Door with the following UML specification:
+---------------------+
| Door |
+---------------------+
| - isOpen: boolean |
+---------------------+
| + Door() |
| + isOpen(): boolean |
| + open(): void |
| + close(): void |
| + testDoor(): void |
+---------------------+
where isOpen is an instance variable indicating whether the door is currently open or not. The default state of a door when it is created is to be closed.
Then create a class Car with the following UML specification:
+---------------------------------------+
| Car |
+---------------------------------------+
| - name: String |
| - doors: Door[] |
+---------------------------------------+
| + Car(String name, int numberOfDoors) |
| + listDoors(): void |
| + countOpenDoors(): int |
| + openOneDoor(int doorNumber): void |
| + testCar(): void |
+---------------------------------------+
Trying to create a car with less than one door must throw a BadCarException with the message "A car must have at least one door!". When a car is created, all its doors are closed.
The method listDoors prints one line of output for each door of the car. Each line starts with the name of the car followed by a message indicating whether the door is currently open or closed. For example, if a car has the name "Tiny" and has two doors, one which is currently open and one which is currently closed, then calling the listDoors method of the car object should produce the following output:
Tiny: door is open
Tiny: door is closed
The method countOpenDoors counts the number of doors of the car which are currently open.
The method openOneDoor opens a specific door, as indicated by the door's number. Doors are numbered starting
from 1 (not 0!) Trying to open a nonexistent door should throw a BadDoorException with the message "Door
XXX does not exist!", where XXX is replaced with the number of the nonexistent door. Trying to open a door
which is already open does nothing.
Use enhanced for loops as much as possible instead of using normal for loops.

// This is the Start class contain the main method
public class Start {

   public static void main(String[] args) throws BadCarException, BadDoorException {
       // Testing each class' testclass
       Door.testDoor();
       System.out.println();
       Car.testCar();
   }

}

Answer 1

class Door {
        private boolean isOpen;

        public Door() {
                this.isOpen = false;
        }

        public boolean isOpen() {
                return isOpen;
        }

        public void close() {
                this.isOpen = false;
        }
        public void open() {
                this.isOpen = true;
        }
        
        public void testDoor() {
                if(isOpen) {
                        System.out.println("door is open");
                } else {
                        System.out.println("door is closed");
                }
        }
}

class Car {
        private String name;
        private Door doors[];
        
        public Car(String name, int numberOfDoors) {
                if(numberOfDoors < 1) {
                        throw new BadCarException("A car must have at least one door!");
                }
                this.name = name;
                doors = new Door[numberOfDoors];
                for(int i=0; i<numberOfDoors; i++) {
                        doors[i] = new Door();
                }
        }
        
        public void listDoors() {
                for(Door d: doors) {
                        System.out.print(name + ": ");
                        d.testDoor();
                }
        }
        
        public int countOpenDoors() {
                int count = 0;
                for(Door d: doors) {
                        if(d.isOpen()) {
                                count++;
                        };
                }
                return count;
        }
        
        public void openOneDoor(int i) {
                i = i - 1;
                
                if(i < 0 || i >= doors.length) {
                        throw new BadDoorException("Door " + (i+1) + " does not exist!");
                }
                
                doors[i].open();
        }
        
        public void testCar() {
                listDoors();
        }
}



public class Start {

   public static void main(String[] args) throws BadCarException, BadDoorException {
       // Testing each class' testclass
       Door d = new Door();
           d.testDoor();
       System.out.println();
       Car c = new Car("Tiny", 3);
           c.testCar();
   }

}

**************************************************

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