PassAClass

import java.util.LinkedList;

public class PassAClass {
    public static void main(String[] args) {
        MagicGun gun = new MagicGun();
        gun.loadWith(Pebbl.class);
        gun.loadWith(Bullet.class);
        gun.loadWith(NuclearMissl.class);
        for(int i=0; i<5; i++){
            try {
                String effect = gun.shoot().getName();
                System.out.printf("You've %sed the target!\n", effect);
            } catch (GunIsEmptyException e) {
                System.err.printf("click\n");
            }
        }
    }
}

class MagicGun {
    LinkedList<Class<? extends Ammo>> ammos = new LinkedList<Class<? extends Ammo>>();
    public void loadWith(Class<? extends Ammo> ammo){
        ammos.add(ammo);
    }
    public Class<? extends Ammo> shoot() throws GunIsEmptyException{
        if (ammos.isEmpty()) {
            throw new GunIsEmptyException();
        }
        return ammos.remove();
    }
}

class GunIsEmptyException extends Exception { }

interface Ammo { }

class Pebbl implements Ammo { }

class Bullet implements Ammo { }

class NuclearMissl implements Ammo { }