/**
 *
 * @author Mutasem
 */
public class System1 {
    public static void Service1(){
   //service logic
    }
    public static void Service2(){
    //
    }
}

public class System2 {
    public static void Service3(){
   //some code
    }
    public static void Service4(){
   //
    }
}
/******************************************************/
public class Facade {

    public void service1() {
         System1.Service1();
    }

    public void service2() {
         System1.Service2();
    }

    public void service3() {
         System2.Service3();
    }

    public void service4() {
         System2.Service4();
    }
}
/*******************************************************/
public class Client {
    public static void main(String[] args) {
        Facade facade=new Facade();
        facade.service1();
        facade.service2();
        facade.service3();
        facade.service4();
        
    }
}

/**
 *
 * @author Mutasem
 */
public abstract class Shape {
    public abstract  void draw();
}

/****************************************/
public class Circle extends Shape{

    @Override
    public void draw() {
        System.out.println("Drawing Circle");
    }
    
}

/***************************************/
public class Rectangle extends Shape{

    @Override
    public void draw() {
        System.out.println("Drawing Rectangle");
    }
    
}

/*******************************/
public class Triangle extends Shape {

    @Override
    public void draw() {
        System.out.println("Drawing Triangle");
    }
}

/**
 *
 * @author Mutasem
 */
public class Client {

    public static void main(String[] args) {
        Circle circle = new Circle();
        Rectangle rectangle = new Rectangle();
        Triangle triangle = new Triangle();
        circle.draw();
        rectangle.draw();
        triangle.draw();
    }

}

/**
 *
 * @author Mutasem
 */
public class Facade {
    Circle circle;
    Triangle triangle;
    Rectangle rectangle;

    public Facade() {
        circle=new Circle();
        triangle=new Triangle();
        rectangle=new Rectangle();
    }
    public void drawCircle(){
    circle.draw();
    }
    public  void drawRect(){
    rectangle.draw();
    }
    public  void drawTri(){
    triangle.draw();
    }
}
/*********************************/
public class Client {

    public static void main(String[] args) {
        Facade facade = new Facade();
        facade.drawCircle();
        facade.drawRect();
        facade.drawTri();
    }

}