工厂方法模式只能处理同一个产品等级下的对象

public interface Human {
  public void getSound();
  public void getColor();
}

public class BlackHuman implements Human {
  @Override
  public void getSound() {
    System.out.println("黑人的肤色是黑的");
  }
  @Override
  public void getColor() {
    System.out.println("黑人喜欢黑色");
  }
}

public class WhiteHuman implements Human {
  @Override
  public void getSound() {
    System.out.println("白人说英语");
  }
  @Override
  public void getColor() {
    System.out.println("白人的肤色一般是白色的");
  }
}

public class YellowHuman implements Human {
  @Override
  public void getSound() {
    System.out.println("黄种人的肤色一般是黄色的");
  }
  @Override
  public void getColor() {
    System.out.println("黄种人一般说汉语");
  }
}

public abstract class MethodFac {
  public static void getAction(Human human){
    human.getColor();
    human.getSound();
  }
  public abstract Human humanFac();

  public static void main(String[] args) {
    getAction(new BlackFac().humanFac());
  }

}

public class BlackFac extends MethodFac {
  public Human humanFac() {
    return new BlackHuman();
  }
}