//: generics/Holder.java

package generics; /* Added by Eclipse.py */

public class Holder<T> {

private T value;

public Holder() {}

public Holder(T val) { value = val; }

public void set(T val) { value = val; }

public T get() { return value; }

public boolean equals(Object obj) {

return value.equals(obj);

}

public static void main(String[] args) {

Holder<Apple> Apple = new Holder<Apple>(new Apple());

Apple d = Apple.get();

Apple.set(d);

// Holder<Fruit> Fruit = Apple; // Cannot upcast

Holder<? extends Fruit> fruit = Apple; // OK

Fruit p = fruit.get();

d = (Apple)fruit.get(); // Returns 'Object'

try {

Orange c = (Orange)fruit.get(); // No warning

} catch(Exception e) { System.out.println(e); }

// fruit.set(new Apple()); // Cannot call set()

// fruit.set(new Fruit()); // Cannot call set()

System.out.println(fruit.equals(d)); // OK

}

} /* Output: (Sample)

java.lang.ClassCastException: Apple cannot be cast to Orange

true

*///:~