Factory, Switch and Random - java

I just started a few weeks ago to learn java. So far I have a problem that I can not get over. I have a mother Class, with 4 extended classes. I have a vector, and want to put in it objects made random using Factory with Switch (I want to use this mode because I do not understand how switch works - I did it with if/else, but not with switch). Can anybody help me? :)

package Tudor;
import java.util.Random;
import java.util.Arrays;
public class Main {

    public static void main(String[] args) {
        Random rd = new Random();
        int tipAnimal = rd.nextInt(4);
       Animal list[] = new Animal[5];

        for (int i = 0; i < list.length;; i++) {
            lista[i] = Factory.buildAnimal(tipAnimal);
        }



package Tudor;

public class Animal {
    Object animal;
 public Animal(Object animal) {
        this.animal = animal;
    }


package Tudor;
public class Dog extends Animal {
}

package Tudor;
public class Cat extends Animal {
}

package Tudor;
public class Doberman extends Dog{
}

package Tudor;
public class Shorthair extends Cat{
}

package Tudor;

public class Factory {
    public static Animal buildAnimal ( Object animal) {

        switch (animal) {
}

The thing is that I can not understand how the cases should be in this switch.