Java - Genéricos

package pruebas;

class Radio {

    private double frequency = 1.1;

//insert appropriate getter and setter

}

class TV {

    private int channel = 5;

//insert appropriate getter and setter

}

public class TestClass {

    public static void main(String[] args) {

	TV t = new TV();

	Radio r = new Radio();

	reset(t);

	reset(r);

	System.out.println(r.getFrequency()); // should print 0.0

	System.out.println(t.getChannel()); // should print 0

    }

}

interface Resetable {    // 1. define una interfaz que tenga el metodo reset

  void reset();

}

class Radio implements Resetable { // 2. haz que cada clase implemente la interface

    private double frequency = 1.1;

    void reset() { // <-- 2.

         frequency = 0.0;

    }

}

class TV implements Resetable { // 2. haz que cada clase implemente la interface

    private int channel = 5;

    void reset() { // <-- 2.

         channel = 0;

    }

}

public class TestClass {

    public static void reset(Resetable r) { // 3. haz que el metodo reciba un objeto que implemente la interface

        r.reset();  // .. y que invoque el metodo reset de esa interface

    }

// sin modificaciones ...

public static void main(String[] args) {

	TV t = new TV();

	Radio r = new Radio();

	reset(t);

	reset(r);

	System.out.println(r.getFrequency()); // should print 0.0

	System.out.println(t.getChannel()); // should print 0

    }

}