Factory Method Pattern

Factory Method Pattern

- 팩토리 객체는 공통 인터페이스 타입 객체를 만드는 팩토리 메소드를 가지고 있다.

- 외부에서 특정 타입 및 파라미터를 받으면 해당 타입에 맞는 팩토리를 호출하여 객체를 생성한다.

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public enum WeaponType {

  SHORT_SWORD("short sword"), SPEAR("spear"), AXE("axe"), UNDEFINED("");

  

private String title;

  WeaponType(String title) {

    this.title = title;

  }

}

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public class OrcWeapon implements Weapon {

  private WeaponType weaponType;

  public OrcWeapon(WeaponType weaponType) {

    this.weaponType = weaponType;

  }

  @Override

  public String toString() {

    return "Orcish " + weaponType;

  }

  @Override

  public WeaponType getWeaponType() {

    return weaponType;

  }

}

---

public class ElfWeapon implements Weapon {

  private WeaponType weaponType;

  public ElfWeapon(WeaponType weaponType) {

    this.weaponType = weaponType;

  }

  @Override

  public String toString() {

    return "Elven " + weaponType;

  }

  @Override

  public WeaponType getWeaponType() {

    return weaponType;

  }

}

---

public interface Weapon {

  WeaponType getWeaponType();

}

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public class OrcBlacksmith implements Blacksmith {

  public Weapon manufactureWeapon(WeaponType weaponType) {

    return new OrcWeapon(weaponType);

  }

}

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public class ElfBlacksmith implements Blacksmith {

  public Weapon manufactureWeapon(WeaponType weaponType) {

    return new ElfWeapon(weaponType);

  }

}

---

public interface Blacksmith {

  Weapon manufactureWeapon(WeaponType weaponType);

}

---

public class App {

  private final Blacksmith blacksmith;

  

  public App(Blacksmith blacksmith) {

    this.blacksmith = blacksmith;

  }

  

  public static void main(String[] args) {

    App app = new App(new OrcBlacksmith());

    app.manufactureWeapons();

    

    app = new App(new ElfBlacksmith());

    app.manufactureWeapons();

  }

  

  private void manufactureWeapons() {

    Weapon weapon;

    weapon = blacksmith.manufactureWeapon(WeaponType.SPEAR);

    System.out.println(weapon.toString());

    weapon = blacksmith.manufactureWeapon(WeaponType.AXE);

    System.out.println(weapon.toString());

  }

}