package com.iluwatar; import java.util.EnumMap; import java.util.Map; /** * * PotionFactory is the Flyweight in this example. * It minimizes memory use by sharing object instances. * It holds a map of potion instances and new potions * are created only when none of the type already exists. * */ public class PotionFactory { private final Map potions; public PotionFactory() { potions = new EnumMap<>(PotionType.class); } Potion createPotion(PotionType type) { Potion potion = potions.get(type); if (potion == null) { switch (type) { case HEALING: potion = new HealingPotion(); potions.put(type, potion); break; case HOLY_WATER: potion = new HolyWaterPotion(); potions.put(type, potion); break; case INVISIBILITY: potion = new InvisibilityPotion(); potions.put(type, potion); break; case POISON: potion = new PoisonPotion(); potions.put(type, potion); break; case STRENGTH: potion = new StrengthPotion(); potions.put(type, potion); break; default: break; } } return potion; } }