Generics usage

AnimalFarm.java

package com.example;

import java.util.HashMap;

final public class AnimalFarm {

    private HashMap<String, Animal> animals = new HashMap<>();

    public AnimalFarm() {
        animals.put("dog", new Dog());
        animals.put("cat", new Cat());
    }

    public <T> T getAnimal(String key, Class<T> type) {
        return type.cast(animals.get(key));
    }

    interface Animal {

        String getType();

        default void printType() {
            System.out.println("I am a " + getType());
        }

    }

    public class Dog implements Animal {

        @Override
        public String getType() {
            return "Dog";
        }
    }

    public class Cat implements Animal {

        @Override
        public String getType() {
            return "Cat";
        }
    }
}

AnimalFarmTest.java

package com.example;

import org.junit.Test;

import static org.junit.Assert.assertEquals;

public class AnimalFarmTest {

    @Test
    public void shouldVerifyAnimals() {

        AnimalFarm animalFarm = new AnimalFarm();

        AnimalFarm.Cat cat = animalFarm.getAnimal("cat", AnimalFarm.Cat.class);

        assertEquals(cat.getType(), "Cat");
        assertEquals(animalFarm.getAnimal("dog", AnimalFarm.Dog.class).getType(), "Dog");

        cat.printType();
    }
}