[Java知识库]SpringBoot下策略模式变体

SpringBoot下策略模式变体

需求

在医院的体检系统中, 会根据体检者的类型不同, 生成不同的体检结论。

通常体检者的类型分为健康体检、 公务员体检、 职业病体检

请根据以上体检类型分别生成不同的体检结论。

UML

代码

体检类型枚举

@Getter
public enum PhysicalExaminationTypeEnum {

    HEALTH_CHECKUP("健康体检"),
    OCCUPATIONAL_DISEASE_EXAMINATION("职业病体检"),
    CIVIL_SERVANT_PHYSICAL_EXAMINATION("公务员体检");

    private final String value;

    PhysicalExaminationTypeEnum(String value) {
        this.value = value;
    }
}

策略

策略接口

public interface ConclusionStrategy {

    /**
     * 生成结论
     *
     * @param resultData 检查结果
     * @return 结论
     */
    String generateConclusion(PhysicalExaminationResultData resultData);

    /**
     * 获取策略类型
     *
     * @return 策略类型
     */
    String getType();
}

健康体检结论策略

@Component
public class HealthConclusionStrategy implements ConclusionStrategy {
    @Override
    public String generateConclusion(PhysicalExaminationResultData resultData) {
        // 根据检查结果生成结论...
        return "健康体检结论策略";
    }

    @Override
    public String getType() {
        return PhysicalExaminationTypeEnum.HEALTH_CHECKUP.getValue();
    }
}

公务员体检结论策略

@Component
public class CivilServantConclusionStrategy implements ConclusionStrategy {
    @Override
    public String generateConclusion(PhysicalExaminationResultData resultData) {
        // 根据检查结果生成结论...
        return "公务员结论";
    }

    @Override
    public String getType() {
        return PhysicalExaminationTypeEnum.CIVIL_SERVANT_PHYSICAL_EXAMINATION.getValue();
    }
}

职业病体检结论策略

@Component
public class OccupationalDiseaseConclusionStrategy implements ConclusionStrategy {
    @Override
    public String generateConclusion(PhysicalExaminationResultData resultData) {
        // 根据检查结果生成结论...
        return "职业病体检结论";
    }

    @Override
    public String getType() {
        return PhysicalExaminationTypeEnum.OCCUPATIONAL_DISEASE_EXAMINATION.getValue();
    }
}

上下文处理器

为调用方提供了统一的方法, 我通常喜欢称其为上下文处理器

@Component
public class ConclusionContextHandler {

    Map<String, ConclusionStrategy> strategyMap;

    // 依赖Spring容器的注入
    @Autowired
    public ConclusionContextHandler(List<ConclusionStrategy> strategies) {
        this.strategyMap = strategies.stream()
                .collect(Collectors.toMap(ConclusionStrategy::getType, s -> s));
    }

    /**
     * 获取结论
     * @param physicalExamNo 体检号
     * @return  结论
     */
    public String getConclusion(String physicalExamNo) {
        final String physicalExaminationType = // 根据体检号查询体检者类型
        final PhysicalExaminationResultData resultData = // 根据体检号查询体检数据
        return strategyMap.get(physicalExaminationType).generateConclusion(resultData);
    }

}

Restful接口

@RestController
@RequestMapping("/conclusion")
public class GeneralInspectionController {
    
    @Resource
    ConclusionContextHandler conclusionContextHandler;
    
	@GetMapping("/{physicalExamNo}")
    public CommonResult<String> getGeneralInspectionConclusion(@PathVariable("physicalExamNo") String physicalExamNo) {
        return CommonResult.success(conclusionContextHandler.getConclusion(physicalExamNo));
    }
}