Complicated Use of Interface in Java.

Main Class:

 
package pkgabstract;

public class Test

{

    public static void main(String[] args)

    {

       Circle c = new Circle(3.5,"Red",true);

       Rectangle r = new Rectangle(5.2,4.2,"Black",true);

       Square s = new Square();

       

        System.out.println("Circle: ");

        System.out.println("Circle Area: "+c.getArea());

        System.out.println("Circle Perimeter: "+c.getPerimeter());

        System.out.println("Circle Color: "+c.toString());

     

        System.out.println("Rectangle: ");

        System.out.println("Rectangle Area: "+r.getArea());

        System.out.println("Rectabgle Perimeter: "+r.getPerimeter());

        System.out.println("Rectangle Color: "+r.toString());

     

        ///for square

        s.setLength(3.1);

        s.setWidth(3.1);

        s.setColor("White");

     

        System.out.println("Square:");

        System.out.println("Square Area: "+s.getArea());

        System.out.println("Square Perimeter: "+s.getPerimeter());

        System.out.println("Square Color: "+s.toString());

     

    }

}

 

Interface Class:

 

package pkgabstract;

 

public interface NewInterface 

{

     public double getArea();

     public double getPerimeter();

     public  String toString();

}

 

Shape Class:

 

package pkgabstract;

 

public class Shape 

{

    private String color;

    private boolean filled;

       

    Shape()

    {

        color = null;

        filled = false;

    }

    

    Shape(String color,boolean filled)

    {

        this.color = color;

        this.filled = filled;

    }

    

    public String getColor()

    {

        return color;

    }

    

    public void setColor(String color)

    {

        this.color = color;

    }

    

     public boolean isFilled()

     {

         return filled;

     }

     

     public void setBoolean(boolean filled)

     {

         this.filled = filled;

     }

            

}

 

Circle Class:

 

 

package pkgabstract;

 

/**

 *

 * @author Sabit

 */

public class Circle extends Shape

{

    private double radius;

    

    Circle()

    {  

        super();

        radius = 0.0;

    }

    

    Circle(double radius)

    {   

        super();

        this.radius = radius;

    }

    

    Circle(double radius,String color,boolean filled)

    {   

        super(color,filled);

        this.radius = radius;

    }

    

    public double getRadius()

    {

        return radius;

    }

    

    public void setRadius(double radius)

    {

        this.radius = radius;

    }

 

    public double getArea() 

    {

       return (Math.PI*Math.pow(radius, 2));

    }

 

   

    public double getPerimeter() 

    {

       return (2*Math.PI*radius);

    }

 

    public String toString() 

    {

      return super.getColor();

    }    

}

 

Rectangle Class:

 

 

package pkgabstract;

 

/**

 *

 * @author Sabit

 */

public class Rectangle extends Shape implements NewInterface

{

    private double width,length;

    

    Rectangle()

    {

        super();

        this.width =0;

        this.length=0;

    }

    

    Rectangle(double width,double length)

    {

        super();

        this.width =width;

        this.length=length;

    }

    

    Rectangle(double width,double length,String color,boolean filled)

    {

        super(color,filled);

        this.width =width;

        this.length=length;

    }

    

    public double getWidth()

    {

        return width;

    }

    

    public void setWidth(double width)

    {

        this.width = width;

    }

    

    public double getLength()

    {

        return length;

    }

    

    public void setLength(double length)

    {

        this.length = length;

    }

            

    @Override

    public double getArea() 

    {

       return (width*length);

    }

 

   

    @Override

    public double getPerimeter() 

    {

        return (2*(width+length));

    }

 

 

    @Override

    public String toString() 

    {

       return super.getColor();

    }

    

}

 

Square Class:

 

 

package pkgabstract;

 

/**

 *

 * @author Sabit

 */

public class Square extends Rectangle implements NewInterface

{  

    Square()

    {

        super();

    }

    

    Square(double side)

    {

        super(side,side);

    }

    

    Square(double side,String color,boolean filled)

    {

        super(side,side,color,filled);

    }

    

    public double getSide()

    {

        return super.getLength();

    }

   

    public void setSide(double side)

    {

        super.setLength(side);

        super.setWidth(side);

    }

   

    @Override

    public void setWidth(double side)

    {

        super.setWidth(side);

    }

    

     @Override

    public void setLength(double side)

    {

        super.setLength(side);

    }

    

    @Override

    public String toString()

    {

        return super.toString();

    }

    

}