Exercise three

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abstract class

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package abstractclass;

public class Circle extends Shape{
	double radius;
	Circle(){
		super();
		this.radius = 0;
	}
	Circle(double r, String c, boolean f){
		super(c, f);
		this.radius = r;
	}
	Circle(double r){
		super();
		this.radius = r;
	}
	public double getRadius() {
		return this.radius;
	}
	
	@Override
	public double getArea() {
		return Math.PI * radius * radius;
	}
	
	@Override
	public double getPerimeter() {
		return Math.PI * 2 * radius;
	}
	
	public String toString() {
		return "A Circle with radius = " + radius + ", which is a subclass of " + super.toString();
	}
}
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package abstractclass;

public class Rectangle extends Shape{
	double width;
	double length;
	
	Rectangle(){
		super();
		this.width = 0;
		this.length = 0;
	}
	Rectangle(double w, double l, String c, boolean f){
		super(c, f);
		this.width = w;
		this.length = l;
	}
	Rectangle(double w, double l){
		super();
		this.width = w;
		this.length = l;
	}
	public double getWidth() {
		return this.width;
	}
	
	public double getLength() {
		return this.length;
	}
	
	@Override
	public double getArea() {
		return width * length;
	}
	
	@Override
	public double getPerimeter() {
		return 2*(width + length);
	}
	
	public String toString() {
		return "A Rectangle with width = "+width+" and length = "+length+", which is a subclass of "+ super.toString();
	}
}
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package abstractclass;

public abstract class Shape {
	protected String color;
	protected boolean filled;
	
	Shape(){
		this.color = "red";
		this.filled = true;
	}
	
	Shape(String c, boolean f){
		this.color = c;
		this.filled = f;
	}
	
	public String getColor() {
		return color;
	}
	
	public boolean isFilled() {
		return filled;
	}
	
	public String toString() {
		if(filled == true)
			return "A Shape with color of " + color + " and filled";
		else
			return "A Shape with color of " + color + " and NOT filled";
	}
	
	public abstract double getArea();
	
	public abstract double getPerimeter();
}
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package abstractclass;
	
public class Square extends Rectangle{
	public Square(double side) {
		 super(side, side); // Call superclass Rectangle(double, double)
	}
	
	public double getSide() {
		return super.getWidth();
	}
	
	public String toString() {
		return "A Square with side = "+super.getLength()+", which is a subclass of "+super.toString();
	}
}
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package abstractclass;

public class Main {
	public static void main(String[] args) {
		
		java.text.DecimalFormat df =new java.text.DecimalFormat("#.00");
		Shape s1 = new Circle(5.5, "green", false); // Upcast Circle to Shape
		System.out.println(s1);  // which version?
		double Area1 = s1.getArea();
		double Perimeter1 = s1.getPerimeter();
		System.out.println(df.format(Area1)); // which version?
		System.out.println(df.format(Perimeter1)); 
		System.out.println(s1.getColor());
		System.out.println(s1.isFilled());
//Shape.test
		
		Circle c1 = (Circle)s1; // Downcast back to Circle
		System.out.println(c1);
		double Area2 = c1.getArea();
		double Perimeter2 = c1.getPerimeter();
		System.out.println(df.format(Area2)); 
		System.out.println(df.format(Perimeter2)); 
		System.out.println(c1.getColor());
		System.out.println(c1.isFilled());
		System.out.println(c1.getRadius());
		
         //       Shape s2 = new Shape(); // Why wrong? : Abstract class cannot be instantiated

//Circle.test
			
		Shape s3 = new Rectangle(1.0, 2.0, "green", false); // Upcast
		System.out.println(s3);
		double Area3 = s3.getArea();
		double Perimeter3 = s3.getPerimeter();
		System.out.println(df.format(Area3)); 
		System.out.println(df.format(Perimeter3)); 
		System.out.println(s3.getColor());

			
		Rectangle r1 = (Rectangle)s3; // downcast
		System.out.println(r1);
		double Area4 = r1.getArea();
		System.out.println(df.format(Area4)); 
		System.out.println(r1.getColor());
		System.out.println(r1.getLength());
//Rectangle.test
		
		Shape s4 = new Square(6.6); // Upcast
		System.out.println(s4);
		double Area5 = s4.getArea();
		System.out.println(df.format(Area5)); 
		System.out.println(s4.getColor());
		
		Rectangle r2 = (Rectangle)s4;
		System.out.println(r2);
		double Area6 = r2.getArea();
		System.out.println(df.format(Area6)); 
		System.out.println(r2.getColor());
		System.out.println(r2.getLength());
		
		Square sq1 = (Square)r2;
		System.out.println(sq1);
		double Area7 = sq1.getArea();
		System.out.println(df.format(Area7)); 
		System.out.println(sq1.getColor());
		System.out.println(sq1.getSide());
		System.out.println(sq1.getLength());
//Square.test

	}
	
	
}

exception

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package exception;

class CircleWithException {
	double radius;
	static int numberOfObjects = 0;
	
	CircleWithException(){
		radius = 0;
		numberOfObjects++;
	}
	
	CircleWithException(double r){
		if(r >= 0)
		{
			radius = r;
			numberOfObjects++;
		}
		else
			throw new IllegalArgumentException("Radius cannot be negative");
	}
	
	public double getRadius() {
		return radius;
	}
	
	public void setRadius(double r) {
		radius = r;
	}
	
	public static int getNumberOfObjects() {
		return numberOfObjects;
	}
	
	public double getArea() {
		return Math.PI * radius * radius;
	}
	
}


public class Main1 {
	public static void main(String[] args) {
		try {
			CircleWithException c1 = new CircleWithException(5);
			CircleWithException c2 = new CircleWithException(-5);
			CircleWithException c3 = new CircleWithException(0);
		}
		catch (IllegalArgumentException ex) {
			System.out.println(ex);
		}
		System.out.println("Number of objects created: " + CircleWithException.getNumberOfObjects() );
	}
}

interface

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package Interface;

public class MovablePoint implements Movable {
	// instance variables
    int x, y, xSpeed, ySpeed; // package access

    // Constructor
    public MovablePoint(int x, int y, int xSpeed, int ySpeed) {
        this.x = x;
        this.y = y;
        this.xSpeed = xSpeed;
        this.ySpeed = ySpeed;
    }

    // Implement abstract methods declared in the interface Movable
    @Override
    public void moveUp() {
        y += ySpeed; 
    }
    
    @Override
    public void moveDown() {
        y -= ySpeed; 
    }
    
    @Override
    public void moveLeft() {
        x -= xSpeed;
    }
    
    @Override
    public void moveRight() {
        x += xSpeed; 
    }
    
    public String toString() {
    	return "MovablePoint (" + x + ", " + y + ") with xSpeed = " + xSpeed + " and ySpeed = " + ySpeed;
    }
}
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package Interface;

public class MovableCircle implements Movable { // saved as "MovableCircle.java"
    // instance variables
    private MovablePoint center; // can use center.x, center.y directly
    // because they are package accessible
    private int radius;

    // Constructor
    public MovableCircle(int x, int y, int xSpeed, int ySpeed, int radius) {
        // Call the MovablePoint's constructor to allocate the center instance.
        center = new MovablePoint(x, y, xSpeed, ySpeed);
        this.radius = radius;
    }
    
    // Implement abstract methods declared in the interface Movable
    @Override
    public void moveUp() {
        center.y += center.ySpeed;
    }
    
    @Override
    public void moveDown() {
        center.y -= center.ySpeed;
    }
    
    @Override
    public void moveLeft() {
        center.x -= center.xSpeed;
    }
    
    @Override
    public void moveRight() {
        center.x += center.xSpeed;
    }
    
    public String toString() {
    	return "MovableCircle at point " + center.toString() + " with radius = " + radius;
    }
}
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package Interface;

public interface Movable {
	public void moveUp();
	public void moveDown();
	public void moveLeft();
	public void moveRight();
}
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package Interface;

public class Main{
	public static void main(String[] args) {
        Movable m1 = new MovablePoint(5, 6, 10, 15); // upcast
        System.out.println(m1);
        m1.moveLeft();
        System.out.println(m1);
        m1.moveUp();
        System.out.println(m1);

        Movable m2 = new MovableCircle(1, 2, 3, 4, 20); // upcast
        System.out.println(m2);
        m2.moveRight();
        System.out.println(m2);
        m2.moveDown();
        System.out.println(m2);
    }
}

superclass

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package superclass;

public class Circle extends Shape{
	double radius;
	Circle(){
		super();
		this.radius = 0;
	}
	Circle(double r, String c, boolean f){
		super(c, f);
		this.radius = r;
	}
	Circle(double r){
		super();
		this.radius = r;
	}
	public double getRadius() {
		return this.radius;
	}
	
	public double getArea() {
		return Math.PI * radius * radius;
	}
	
	public double getPerimeter() {
		return Math.PI * 2 * radius;
	}
	
	public String toString() {
		return "A Circle with radius = " + radius + ", which is a subclass of " + super.toString();
	}
}
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package superclass;

public class Rectangle extends Shape{
	double width;
	double length;
	
	Rectangle(){
		super();
		this.width = 0;
		this.length = 0;
	}
	Rectangle(double w, double l, String c, boolean f){
		super(c, f);
		this.width = w;
		this.length = l;
	}
	Rectangle(double w, double l){
		super();
		this.width = w;
		this.length = l;
	}
	public double getWidth() {
		return this.width;
	}
	
	public double getLength() {
		return this.length;
	}
	
	
	public double getArea() {
		return width * length;
	}
	
	public double getPerimeter() {
		return 2*(width + length);
	}
	
	public String toString() {
		return "A Rectangle with width = "+width+" and length = "+length+", which is a subclass of "+ super.toString();
	}
}
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package superclass;

public class Shape {
	String color;
	boolean filled;
	
	Shape(){
		this.color = "red";
		this.filled = true;
	}
	
	Shape(String c, boolean f){
		this.color = c;
		this.filled = f;
	}
	
	public String getColor() {
		return color;
	}
	
	public boolean isFilled() {
		return filled;
	}
	
	public String toString() {
		if(filled == true)
			return "A Shape with color of " + color + " and filled";
		else
			return "A Shape with color of " + color + " and NOT filled";
	}
}
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package superclass;

public class Square extends Rectangle{
	public Square(double side) {
		 super(side, side); // Call superclass Rectangle(double, double)
	}
	
	public double getSide() {
		return super.getWidth();
	}
	
	public String toString() {
		return "A Square with side = "+super.getLength()+", which is a subclass of "+super.toString();
	}
}
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package superclass;

public class Main {
	public static void main(String[] args) {
	
	// Upcast Circle to Shape
	Shape s1 = new Circle(5.5, "green", false); 
	System.out.println(s1);
	System.out.println(s1.getColor());
	System.out.println(s1.isFilled());

	// Downcast back to Circle
	Circle c1 = (Circle)s1; 
	System.out.println(c1);
	System.out.println(c1.getColor());
	System.out.println(c1.isFilled());

	// Upcast
	Shape s2 = new Rectangle(1.0, 2.0, "green", false); 
	System.out.println(s2);
	System.out.println(s2.getColor());

	//Downcast
	Rectangle r1 =  (Rectangle)s2; 
	System.out.println(r1);
	System.out.println(r1.getArea());
	System.out.println(r1.getColor());
	System.out.println(r1.getLength());

	// Upcast
	Shape s3 = new Square(6.6); 
	System.out.println(s3);
	System.out.println(s3.getColor());

	
	Rectangle r2 =  (Rectangle)s3; 
	System.out.println(r2);
	java.text.DecimalFormat df =new java.text.DecimalFormat("#.00");
	double area1 = r2.getArea();
	System.out.println(df.format(area1));
	System.out.println(r2.getColor());
	System.out.println(r2.getLength());

	
	// Downcast Rectangle r2 to Square
	Square sq1 = (Square)r2;
	System.out.println(sq1);
	area1 = sq1.getArea();
	System.out.println(df.format(area1));
	System.out.println(sq1.getColor());
	System.out.println(sq1.getSide());
	System.out.println(sq1.getLength());
}


}
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