210629 Java - 인터페이스, 추상클래스, 상속, 다형성

클래스 다이어그램

실행결과

클래스 다이어그램을 보고 클래스를 만들어 실행결과를 도출해라

 

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Resize.java

public interface Resize {
	void setResize(int size);
}

 

Shape.java

public abstract class Shape {
	private int length;
	private int width;
	private String colors;

	public Shape() {
		super();
	}

	public Shape(int length, int width, String colors) {
		super();
		this.length = length;
		this.width = width;
		this.colors = colors;
	}

	public int getLength() {
		return length;
	}

	public void setLength(int length) {
		this.length = length;
	}

	public int getWidth() {
		return width;
	}

	public void setWidth(int width) {
		this.width = width;
	}

	public String getColors() {
		return colors;
	}

	public void setColors(String colors) {
		this.colors = colors;
	}

	public abstract double getArea();

}

 

Triangle.java

public class Triangle extends Shape implements Resize {

	public Triangle() {
		super();
	}

	public Triangle(int length, int width, String color) {
		super(length, width, color);
	}

	@Override
	public void setResize(int size) {
		super.setLength(size + super.getLength());
	}

	@Override
	public double getArea() {
		double area = super.getLength() * (double)super.getWidth() / 2;
		return area;
	}

}

 

Rectangle.java

public class Rectangle extends Shape implements Resize {

	public Rectangle() {
		super();
	}

	public Rectangle(int length, int width, String color) {
		super(length, width, color);
	}

	@Override
	public void setResize(int size) {
		super.setWidth(size + super.getWidth());
	}

	@Override
	public double getArea() {
		double area = super.getLength() * super.getWidth();
		return area;
	}

}

 

ShapeTest.java (main)

public class ShapeTest {

	public static void main(String[] args) {
		Shape[] sm = new Shape[6];

		sm[0] = new Triangle(7, 5, "Blue");
		sm[1] = new Rectangle(4, 6, "Blue");
		sm[2] = new Triangle(6, 7, "Red");
		sm[3] = new Rectangle(8, 3, "Red");
		sm[4] = new Triangle(9, 8, "White");
		sm[5] = new Rectangle(5, 7, "White");

		System.out.println("기본정보");
		System.out.println();
		String shapeType = null;

		for (int i = 0; i < sm.length; i++) {
			Shape s = (Shape) sm[i];

			if (s instanceof Triangle) {
				shapeType = "Triagnle";
			}

			if (s instanceof Rectangle) {
				shapeType = "Rectangle";
			}

			System.out.println(shapeType + "\t" + s.getArea() + "\t" + s.getColors());
		}

		System.out.println();
		System.out.println("사이즈를 변경 후 정보");
		System.out.println();

		for (int i = 0; i < sm.length; i++) {
			Shape s = (Shape) sm[i];

			if (s instanceof Triangle) {
				shapeType = "Triangle";
				((Triangle) s).setResize(5);
			}

			if (s instanceof Rectangle) {
				shapeType = "Rectangle";
				((Rectangle) s).setResize(5);
			}

			System.out.println(shapeType + "\t" + s.getArea() + "\t" + s.getColors());
		}
	}

}