PECS example

gistfile1.java

public static void getOldSeaAnimals(List<? extends SeaAnimal> animals, List<? super SeaAnimal> oldAnimals)
{
    for (SeaAnimal animal:animals)
    {
        if (animal.getAge() > 100)
        {
            oldAnimals.add(animal);
        }
    }
}

public static void exampleCalls() {
    List<SeaAnimal> input1 = new ArrayList<SeaAnimal>();
    List<Animal> output1 = new ArrayList<Animal>();
    input1.add(new Fish(200));
    input1.add(new Fish(150));
    input1.add(new Fish(300));
       
    AnimalUtils.getOldSeaAnimals(input1, output1);
       
    List<Fish> input2 = new ArrayList<Fish>();
    List<SeaAnimal> output2 = new ArrayList<SeaAnimal>();
    input2.add(new Fish(200));
    input2.add(new Fish(150));
    input2.add(new Fish(300));
    AnimalUtils.getOldSeaAnimals(input2, output2);
}