原型模式

原型设计模式UML类图

原型设计模式java实现

/**
 * Prototype.
 */
public interface Prototype {

  Object copy();

}

/**
 * Beast.
 */
public abstract class Beast implements Prototype {

  public Beast() {
  }

  public Beast(Beast source) {
  }

  @Override
  public abstract Beast copy();

  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (obj == null) {
      return false;
    }
    return getClass() == obj.getClass();
  }

}

/**
 * OrcBeast.
 */
public class OrcBeast extends Beast {

  private String weapon;

  public OrcBeast(String weapon) {
    this.weapon = weapon;
  }

  public OrcBeast(OrcBeast orcBeast) {
    super(orcBeast);
    this.weapon = orcBeast.weapon;
  }

  @Override
  public OrcBeast copy() {
    return new OrcBeast(this);
  }

  @Override
  public String toString() {
    return "Orcish wolf attacks with " + weapon;
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (!super.equals(obj)) {
      return false;
    }
    if (getClass() != obj.getClass()) {
      return false;
    }
    var other = (OrcBeast) obj;
    if (weapon == null) {
      return other.weapon == null;
    }
    return weapon.equals(other.weapon);
  }


}

/**
 * ElfBeast.
 */
public class ElfBeast extends Beast {

  private String helpType;

  public ElfBeast(String helpType) {
    this.helpType = helpType;
  }

  public ElfBeast(ElfBeast elfBeast) {
    super(elfBeast);
    this.helpType = elfBeast.helpType;
  }

  @Override
  public ElfBeast copy() {
    return new ElfBeast(this);
  }

  @Override
  public String toString() {
    return "Elven eagle helps in " + helpType;
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (!super.equals(obj)) {
      return false;
    }
    if (getClass() != obj.getClass()) {
      return false;
    }
    var other = (ElfBeast) obj;
    if (helpType == null) {
      return other.helpType == null;
    }
    return helpType.equals(other.helpType);
  }

}

/**
 * Warlord.
 */
public abstract class Warlord implements Prototype {

  public Warlord() {
  }

  public Warlord(Warlord source) {
  }

  @Override
  public abstract Warlord copy();

  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (obj == null) {
      return false;
    }
    return getClass() == obj.getClass();
  }

}

/**
 * OrcWarlord.
 */
public class OrcWarlord extends Warlord {

  private String weapon;

  public OrcWarlord(String weapon) {
    this.weapon = weapon;
  }

  public OrcWarlord(OrcWarlord orcWarlord) {
    super(orcWarlord);
    this.weapon = orcWarlord.weapon;
  }

  @Override
  public OrcWarlord copy() {
    return new OrcWarlord(this);
  }

  @Override
  public String toString() {
    return "Orcish warlord attacks with " + weapon;
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (!super.equals(obj)) {
      return false;
    }
    if (getClass() != obj.getClass()) {
      return false;
    }
    var other = (OrcWarlord) obj;
    if (weapon == null) {
      return other.weapon == null;
    }
    return weapon.equals(other.weapon);
  }
}

/**
 * ElfWarlord.
 */
public class ElfWarlord extends Warlord {

  private String helpType;

  public ElfWarlord(String helpType) {
    this.helpType = helpType;
  }

  public ElfWarlord(ElfWarlord elfWarlord) {
    super(elfWarlord);
    this.helpType = elfWarlord.helpType;
  }

  @Override
  public ElfWarlord copy() {
    return new ElfWarlord(this);
  }

  @Override
  public String toString() {
    return "Elven warlord helps in " + helpType;
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (!super.equals(obj)) {
      return false;
    }
    if (getClass() != obj.getClass()) {
      return false;
    }
    var other = (ElfWarlord) obj;
    if (helpType == null) {
      return other.helpType == null;
    }
    return helpType.equals(other.helpType);
  }
}

/**
 * Mage.
 */
public abstract class Mage implements Prototype {

  public Mage() {
  }

  public Mage(Mage source) {
  }

  @Override
  public abstract Mage copy();

  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (obj == null) {
      return false;
    }
    return getClass() == obj.getClass();
  }

}

/**
 * OrcMage.
 */
public class OrcMage extends Mage {

  private String weapon;

  public OrcMage(String weapon) {
    this.weapon = weapon;
  }

  public OrcMage(OrcMage orcMage) {
    super(orcMage);
    this.weapon = orcMage.weapon;
  }

  @Override
  public OrcMage copy() {
    return new OrcMage(this);
  }

  @Override
  public String toString() {
    return "Orcish mage attacks with " + weapon;
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (!super.equals(obj)) {
      return false;
    }
    if (getClass() != obj.getClass()) {
      return false;
    }
    var other = (OrcMage) obj;
    if (weapon == null) {
      return other.weapon == null;
    }
    return weapon.equals(other.weapon);
  }
}

/**
 * ElfMage.
 */
public class ElfMage extends Mage {

  private String helpType;

  public ElfMage(String helpType) {
    this.helpType = helpType;
  }

  public ElfMage(ElfMage elfMage) {
    super(elfMage);
    this.helpType = elfMage.helpType;
  }

  @Override
  public ElfMage copy() {
    return new ElfMage(this);
  }

  @Override
  public String toString() {
    return "Elven mage helps in " + helpType;
  }

  @Override
  public boolean equals(Object obj) {
    if (this == obj) {
      return true;
    }
    if (!super.equals(obj)) {
      return false;
    }
    if (getClass() != obj.getClass()) {
      return false;
    }
    var other = (ElfMage) obj;
    if (helpType == null) {
      return other.helpType == null;
    }
    return helpType.equals(other.helpType);
  }
}

/**
 * Interface for the factory class.
 */
public interface HeroFactory {

  Mage createMage();

  Warlord createWarlord();

  Beast createBeast();

}

/**
 * Concrete factory class.
 */
public class HeroFactoryImpl implements HeroFactory {

  private Mage mage;
  private Warlord warlord;
  private Beast beast;

  /**
   * Constructor.
   */
  public HeroFactoryImpl(Mage mage, Warlord warlord, Beast beast) {
    this.mage = mage;
    this.warlord = warlord;
    this.beast = beast;
  }

  /**
   * Create mage.
   */
  public Mage createMage() {
    return mage.copy();
  }

  /**
   * Create warlord.
   */
  public Warlord createWarlord() {
    return warlord.copy();
  }

  /**
   * Create beast.
   */
  public Beast createBeast() {
    return beast.copy();
  }

}

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * The Prototype pattern is a creational design pattern in software development. It is used when the
 * type of objects to create is determined by a prototypical instance, which is cloned to produce
 * new objects. This pattern is used to: - avoid subclasses of an object creator in the client
 * application, like the abstract factory pattern does. - avoid the inherent cost of creating a new
 * object in the standard way (e.g., using the 'new' keyword)
 *
 * <p>In this example we have a factory class ({@link HeroFactoryImpl}) producing objects by
 * cloning the existing ones. The factory's prototype objects are given as constructor parameters.
 */
public class App {

  private static final Logger LOGGER = LoggerFactory.getLogger(App.class);

  /**
   * Program entry point.
   *
   * @param args command line args
   */
  public static void main(String[] args) {
    var factory = new HeroFactoryImpl(
        new ElfMage("cooking"),
        new ElfWarlord("cleaning"),
        new ElfBeast("protecting")
    );
    var mage = factory.createMage();
    var warlord = factory.createWarlord();
    var beast = factory.createBeast();
    LOGGER.info(mage.toString());
    LOGGER.info(warlord.toString());
    LOGGER.info(beast.toString());

    factory = new HeroFactoryImpl(
        new OrcMage("axe"),
        new OrcWarlord("sword"),
        new OrcBeast("laser")
    );
    mage = factory.createMage();
    warlord = factory.createWarlord();
    beast = factory.createBeast();
    LOGGER.info(mage.toString());
    LOGGER.info(warlord.toString());
    LOGGER.info(beast.toString());
  }
}