[파워자바] 12장 프로그래밍 솔루션 답지

 

1.

interface Movable
{
	void move(int dx, int dy);
}
class Shape implements Movable {
	protected int x, y;

	public void draw() {
		System.out.println("Shape Draw");
	}

	public void move(int dx, int dy) {
		x = dx;
		y = dy;
	}
};

class Rectangle extends Shape {
	private int width, height;

	public void setWidth(int w) {
		width = w;
	}

	public void setHeight(int h) {
		height = h;
	}

	public void draw() {
		System.out.println("Rectangle Draw");
	}

};

class Triangle extends Shape {
	private int base, height;

	public void draw() {
		System.out.println("Triangle Draw");
	}

	@Override
	public void move(int dx, int dy) {
		x = dx;
		y = dy;
	}
};

class Circle extends Shape {
	private int radius;

	public void draw() {
		System.out.println("Circle Draw");
	}

};

public class ShapeTest {
	private static Movable arrayOfShapes[];

	public static void main(String arg[]) {
		init();
		moveAll();
	}

	public static void init() {
		arrayOfShapes = new Shape[3];
		arrayOfShapes[0] = new Rectangle();
		arrayOfShapes[1] = new Triangle();
		arrayOfShapes[2] = new Circle();
	}

	public static void moveAll() {
		for (int i = 0; i < arrayOfShapes.length; i++) {
			arrayOfShapes[i].move(10, 10);
		}
	}
};

 

2.

interface Drawable {
	void draw();
}

class Shape implements Drawable {
	protected int x, y;

	public void draw() {
		System.out.println("Shape Draw");
	}
};

class Rectangle extends Shape {
	private int width, height;

	public void setWidth(int w) {
		width = w;
	}

	public void setHeight(int h) {
		height = h;
	}

	public void draw() {
		System.out.println("Rectangle Draw");
	}

};

class Triangle extends Shape {
	private int base, height;

	public void draw() {
		System.out.println("Triangle Draw");
	}
};

class Circle extends Shape {
	private int radius;

	public void draw() {
		System.out.println("Circle Draw");
	}

};

public class ShapeTest {
	private static Drawable arrayOfShapes[];

	public static void main(String arg[]) {
		init();
		drawAll();
	}

	public static void init() {
		arrayOfShapes = new Shape[3];
		arrayOfShapes[0] = new Rectangle();
		arrayOfShapes[1] = new Triangle();
		arrayOfShapes[2] = new Circle();
	}

	public static void drawAll() {
		for (int i = 0; i < arrayOfShapes.length; i++) {
			arrayOfShapes[i].draw();
		}
	}
};

 

3.

interface controllable  {
	void play();
	void stop();
}
public class Test {
	public static void main(String arg[]) {
		controllable c = new controllable() {
			public void play() {
				System.out.println("PLAY");
			}

			public void stop() {
				System.out.println("STOP");
			}
			
		};
		c.play();
		c.stop();
	}
};

 

4.

interface Comparable {
       // 이 객체가 다른 객체보다 크면 1, 같으면 0, 작으면 -1을 반환한다.
       int compareTo(Object other);
}
class Person implements Comparable {
	@Override
	public String toString() {
		return "Person [name=" + name + ", height=" + height + "]";
	}
	public Person(String name, double height) {
		super();
		this.name = name;
		this.height = height;
	}
	String name;
	double height;
	@Override
	public int compareTo(Object other) {
		if ( this.height > ((Person)other).height )
			return 1;
		else if ( this.height == ((Person)other).height )
			return 0;
		else 
			return -1;
	}
}

public class Test {
	public static Person getMaximum(Person[] array)
	{
		Person max=array[0];
		
		for(int i=1;i<array.length;i++){
			if( array[i].height > max.height )
				max = array[i];
		}
			
		return max;
	}
	public static void main(String arg[]) {
			Person[] array;
			array = new Person[3];
			array[0] = new Person("홍길동1", 190);
			array[1] = new Person("홍길동2", 180);
			array[2] = new Person("홍길동3", 185);
			System.out.println(getMaximum(array));
	}
}