java实现策略模式

无区新手2024-09-12 5:04

创建策略接口

java 复制代码

public interface Calculate {

    public int operation(int a, int b);

}

实现接口

加法策略

java 复制代码

@Component
public class AddCalculate implements Calculate {
    @Override
    public int operation(int a, int b) {
        return a + a;
    }
}

减法策略

java 复制代码

@Component
public class SubCalculate implements Calculate {
    @Override
    public int operation(int a, int b) {
        return a - a;
    }
}

策略实现类

在springboot中，对于添加了 @Autowired的map会自动将实现类注入到map中，key是beanid，value是注入的对象实例

java 复制代码

@Component
public class CalculateFactory {

    @Autowired
    private Map<String, Calculate> calculateMap;

    public int calculate(String calculate, int a, int b) throws Exception {
        return Optional.ofNullable(calculateMap.get(calculate))
                .orElseThrow(() -> new RuntimeException("异常")).operation(a, b);
    }

}

使用

java 复制代码

@RestController
@RequestMapping("/demo")
public class DemoController {

    @Autowired
    private CalculateFactory calculateFactory;

    @GetMapping("/calculate")
    public int calculate() throws Exception {
        return calculateFactory.calculate("addCalculate", 1, 1);
    }

}