diff --git a/localization/zh/crtp/README.md b/localization/zh/crtp/README.md new file mode 100644 index 000000000..80632021a --- /dev/null +++ b/localization/zh/crtp/README.md @@ -0,0 +1,134 @@ +--- +title: Curiously Recurring Template Pattern +language: zh +category: Structural +tag: +- Extensibility +- Instantiation +--- + +## 名称/分类 + +Curiously Recurring Template Pattern,CRTP,奇异递归模板模式 + +## 别名 + +递归类型绑定,递归泛型 + +## 目的 + +允许派生组件从与派生类型兼容的基本组件继承某些功能。 + +## 解释 + +真实世界的例子 + +> 对于正在策划赛事的综合格斗推广活动来说,确保在相同重量级的运动员之间组织比赛至关重要。这样可以防止体型明显不同的拳手之间的不匹配,例如重量级拳手与雏量级拳手的对决。 + +用通俗的话来讲 + +> 使类型中的某些方法接受特定于其子类型的参数。 + +维基百科介绍 + +> 奇异递归模板模式(curiously recurring template pattern,CRTP)是C++模板编程时的一种惯用法:其中类X派生自使用X本身作为模板参数的类模板实例化。 + +**程序示例** + +让我们来定义通用接口Fighter + +```java +public interface Fighter { + + void fight(T t); + +} +``` + +MmaFighter类用于实例化按重量级别区分的拳手 + +``` Java +public class MmaFighter> implements Fighter { + + private final String name; + private final String surname; + private final String nickName; + private final String speciality; + + public MmaFighter(String name, String surname, String nickName, String speciality) { + this.name = name; + this.surname = surname; + this.nickName = nickName; + this.speciality = speciality; + } + + @Override + public void fight(T opponent) { + LOGGER.info("{} is going to fight against {}", this, opponent); + } + + @Override + public String toString() { + return name + " \"" + nickName + "\" " + surname; + } +``` + +以下是 MmaFighter 的一些子类型 + +```Java +class MmaBantamweightFighter extends MmaFighter { + + public MmaBantamweightFighter(String name, String surname, String nickName, String speciality) { + super(name, surname, nickName, speciality); + } + +} + +public class MmaHeavyweightFighter extends MmaFighter { + + public MmaHeavyweightFighter(String name, String surname, String nickName, String speciality) { + super(name, surname, nickName, speciality); + } + +} +``` + +允许拳手与相同重量级的对手交手,如果对手是不同重量级,则会出现错误 + +``` Java +MmaBantamweightFighter fighter1 = new MmaBantamweightFighter("Joe", "Johnson", "The Geek", "Muay Thai"); +MmaBantamweightFighter fighter2 = new MmaBantamweightFighter("Ed", "Edwards", "The Problem Solver", "Judo"); +fighter1.fight(fighter2); // This is fine + +MmaHeavyweightFighter fighter3 = new MmaHeavyweightFighter("Dave", "Davidson", "The Bug Smasher", "Kickboxing"); +MmaHeavyweightFighter fighter4 = new MmaHeavyweightFighter("Jack", "Jackson", "The Pragmatic", "Brazilian Jiu-Jitsu"); +fighter3.fight(fighter4); // This is fine too + +fighter1.fight(fighter3); // This will raise a compilation error +``` + +## 类图 + +![alt text](etc/crtp.png "CRTP class diagram") + +## 适用性 + +在以下情况下使用CRTP + +* 在对象层次结构中链接方法时存在类型冲突 +* 您想使用一个参数化的类方法,该方法可以接受类的子类作为参数,从而可以应用于继承自类的对象 +* 您希望某些方法仅适用于相同类型的实例,例如实现相互比较。 + +## 教程 + +* [The NuaH Blog](https://nuah.livejournal.com/328187.html) +* Yogesh Umesh Vaity answer to [What does "Recursive type bound" in Generics mean?](https://stackoverflow.com/questions/7385949/what-does-recursive-type-bound-in-generics-mean) + +## 已知用途 + +* [java.lang.Enum](https://docs.oracle.com/en/java/javase/17/docs/api/java.base/java/lang/Enum.html) + +## 鸣谢 + +* [How do I decrypt "Enum>"?](http://www.angelikalanger.com/GenericsFAQ/FAQSections/TypeParameters.html#FAQ106) +* Chapter 5 Generics, Item 30 in [Effective Java](https://www.amazon.com/gp/product/0134685997/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0134685997&linkCode=as2&tag=javadesignpat-20&linkId=4e349f4b3ff8c50123f8147c828e53eb) diff --git a/localization/zh/crtp/etc/crtp.png b/localization/zh/crtp/etc/crtp.png new file mode 100644 index 000000000..a348c8af6 Binary files /dev/null and b/localization/zh/crtp/etc/crtp.png differ