Abstract classes, interfaces and polimorfism.

• abstract classes
• interfaces
• polimorfism

Polimorfismul
Clase abstracte si interfete
Thinking in Java : Chapter 7 - Polimorphism
Diagrama de clase
Implementarea diagramelor UML in Java

Follow the instructions and implement the program according to specification . Create an appropriate test class for testing the program.

In this exercise, Shape shall be defined as an abstract class, which contains:

• Two protected instance variables color(String) and filled(boolean). The protected variables can be accessed by its subclasses and classes in the same package. They are denoted with a '#' sign in the class diagram.
• Getter and setter for all the instance variables, and toString().
• Two abstract methods getArea() and getPerimeter() (shown in italics in the class diagram).
• The subclasses Circle and Rectangle shall override the abstract methods getArea() and getPerimeter() and provide the proper implementation. They also override the toString().

Create the UML class diagram for the program bellow. Add a new type of bird, and modify BirdController in order to handle the new type of bird.

class Bird {
            public void move(){
                        System.out.println("The bird is moving.");
            }
}
 
class Penguin extends Bird{
            public void move(){
                        System.out.println("The PENGUIN is swiming.");
            }
}
 
class Goose extends Bird{
            public void move(){
                        System.out.println("The GOOSE is flying.");
            }
}
 
public class BirdController{
            Bird[] birds = new Bird[3];
            BirdController(){
                        birds[0] = createBird();
                        birds[1] = createBird();
                        birds[2] = createBird();
            }
            public void relocateBirds(){
                        for(int i=0;i<birds.length;i++)
                                    birds[i].move();
            }
 
            private Bird createBird(){
                        int i = (int)(Math.random()*10);
                        if(i<5)
                                    return new Penguin();
                        else
                                    return new Goose();
            }
 
            public static void main(String [] args){
                        BirdController bc = new BirdController();
                        bc.relocateBirds();
            }          
}

Implement application based on the UML class diagram bellow. Create a test class for testing the program.

Implement application based on the UML class diagram bellow. Create a test class for testing the program.