[单例模式](%E5%8D%95%E4%BE%8B%E6%A8%A1%E5%BC%8F.md) [装饰者模式](%E8%A3%85%E9%A5%B0%E8%80%85%E6%A8%A1%E5%BC%8F.md) [工厂模式](%E5%B7%A5%E5%8E%82%E6%A8%A1%E5%BC%8F.md)