lab 9 close #7

lab/lab9/Question2/Car.java

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+/*
+ * Author: CHEN Yongyuan (Walter) 1930006025 from OOP(1007)
+ * Date: 2022-04-21
+ * Description: This is the class of Door.
+ */
+
+public class Car {
+	private String name;
+	private Door[] doors;
+
+	/**
+	 * Constructor.
+	 *
+	 * @param name          The name of the car.
+	 * @param numberOfDoors The number of doors.
+	 * @throws BadCarException If the number of doors is less than 1.
+	 */
+	public Car(String name, int numberOfDoors) throws BadCarException {
+		if (numberOfDoors < 1) {
+			throw new BadCarException("A car must have at least one door!");
+		}
+
+		this.name = name;
+
+		// initialise the doors array
+		doors = new Door[numberOfDoors];
+		for (int i = 0; i < numberOfDoors; i++) {
+			doors[i] = new Door();
+		}
+	}
+
+	/**
+	 * Prints each door of the car.
+	 */
+	public void listDoors() {
+		for (Door door : doors) {
+			System.out.println(String.format("%s: door is %s", name, door.isOpen() ? "open" : "closed"));
+		}
+	}
+
+	/**
+	 * Count the numer of open doors.
+	 *
+	 * @return The number of open doors.
+	 */
+	public int countOpenDoors() {
+		int count = 0;
+		for (Door door : doors) {
+			if (door.isOpen()) {
+				count++;
+			}
+		}
+		return count;
+	}
+
+	/**
+	 * Open one door with number start from 1.
+	 *
+	 * @param doorNumber The number of the door to open start from 1.
+	 * @throws BadDoorException If try to open a non-existed door.
+	 */
+	public void openOneDoor(int doorNumber) throws BadDoorException {
+		doorNumber--;
+		if (doorNumber < 0 || doorNumber >= doors.length || doors[doorNumber] == null) {
+			throw new BadDoorException(String.format("Door %d does not exist!", doorNumber + 1));
+		}
+
+		doors[doorNumber].open();
+	}
+
+	/**
+	 * Open all the closed doors and closes all the open doors.
+	 */
+	public void changeAllDoors() {
+		for (Door door : doors) {
+			if (door.isOpen()) {
+				door.close();
+			} else {
+				door.open();
+			}
+		}
+	}
+
+	/**
+	 * Test.
+	 */
+	public static void testCar() {
+		try {
+			Car brokencar = new Car("Broken", 0);
+		} catch (BadCarException ex) {
+			System.out.println(ex.getMessage() == "A car must have at least one door!");
+		}
+		Car c = null;
+		try {
+			c = new Car("Biggy", 7);
+		} catch (BadCarException ex) {
+			System.out.println("BUG! This must never happen!");
+		}
+		c.listDoors();
+		System.out.println(c.countOpenDoors() == 0);
+		c.changeAllDoors();
+		System.out.println(c.countOpenDoors() == 7);
+		c.listDoors();
+		c.changeAllDoors();
+		System.out.println(c.countOpenDoors() == 0);
+		try {
+			c.openOneDoor(8);
+		} catch (BadDoorException ex) {
+			System.out.println(ex.getMessage().equals("Door 8 does not exist!"));
+		}
+		try {
+			c.openOneDoor(3);
+		} catch (BadDoorException ex) {
+			System.out.println("BUG! This must never happen!");
+		}
+		System.out.println(c.countOpenDoors() == 1);
+		c.changeAllDoors();
+		System.out.println(c.countOpenDoors() == 6);
+		c.listDoors();
+		c.changeAllDoors();
+		System.out.println(c.countOpenDoors() == 1);
+		c.listDoors();
+	}
+}