JAVA笔记 | 实际上用到的策略模式(可直接套用)

自己开发中用到了策略模式，这样写不一定是最好的，但是满足了业务场景跟使用要求，做个笔记，下次有用到可以快速复习跟套用

假设使用场景：有几只宠物，猫跟狗等，要求他们做各种动作，比如叫，跑等，但是作为宠物这些都是相同的动作，只是猫，狗具体的表现不同，比如猫叫是喵，狗叫是汪

1.创建基础策略接口PetStrategy

public interface PetStrategy {//类型 cat-猫，dog-狗String getType();//执行动作 1 - 叫barkString bark();//执行动作 2 - 跑RUN 带参数例子String run(String name);
}

2.创建实现PetStrategy接口的猫CatStrategy跟狗DogStrategy用于实现具体的表现

注意加上@Service

//猫实现类
@Service
public class CatStrategy implements PetStrategy{@Overridepublic String getType() {return "cat";}@Overridepublic String bark() {return "猫叫喵喵喵";}@Overridepublic String run(String name) {return name + "猫跑了";}
}//狗实现类
@Service
public class DogStrategy implements PetStrategy{@Overridepublic String getType() {return "dog";}@Overridepublic String bark() {return "狗叫汪汪汪";}@Overridepublic String run(String name) {return name + "狗跑了";}
}

3.创建统一策略入口，即不同宠物类型type进来进行分配对应的策略

public interface PetStrategyHandler {//宠物叫行为String bark(String type);//宠物跑行为-带入参String run(String type,String name);
}

4.创建入口配置类，接收入口传来的type，用于实际分配不同的策略，类似工厂

@Configuration
public class PetStrategyConfig {@Beanpublic PetStrategyHandler petHandler(List<PetStrategy> strategies) {Map<String, PetStrategy> strategyMap = strategies.stream().collect(Collectors.toMap(PetStrategy::getType, item -> item));PetStrategyHandler handler = new PetStrategyHandler() {@Overridepublic String bark(String type) {return strategyMap.get(type).bark();}@Overridepublic String run(String type,String name) {return strategyMap.get(type).run(name);}};return handler;}
}

5.创建controller测试

@RestController
@RequestMapping("/pet")
public class PetController {@Resourceprivate PetStrategyHandler handler;@GetMapping("/bark/{type}")public String bark(@PathVariable String type){return this.handler.bark(type);}@GetMapping("/run/{type}")public String run(@PathVariable String type,@RequestParam String name){return this.handler.run(type,name);}
}