策略模式应用审批

需求如图

 

需要依据动作 来执行 状态的改变

最开始 写法：

 

public enum AuditActionEnum {

    commit("commit", "提交审核"),
    approvePass("approvePass", "审核通过"),
    approveReject("approveReject", "审核拒绝");

    private String key;
    private String desc;

    AuditActionEnum(String key, String desc) {
        this.key = key;
        this.desc = desc;
    }

    public String getKey() {
        return this.key;
    }
    public String getDesc() {
        return this.desc;
    }

    public static AuditActionEnum match(String key) {
        for (AuditActionEnum e : AuditActionEnum.values()) {
            if (e.getKey().equals(key)) {
                return e;
            }
        }
        return null;
    }
}

通过状态：来做对应的数据库处理

if (AuditActionEnum.commit.getKey().equals(auditAction)) {
    updateWrapper.set("audit_state", AuditStateEnum.committed.getKey());
    updateWrapper.set("commit_time", auditCommitResDto.getCommitTime() == null ? DateUtil.getCurrentDatetime() : auditCommitResDto.getCommitTime());
}
if (AuditActionEnum.approvePass.getKey().equals(auditAction)) {
    updateWrapper.set("is_master", EffectMasterEnum.master.getKey());
    updateWrapper.set("is_effective", EffectMasterEnum.effect.getKey());
    updateWrapper.set("audit_time", auditCommitResDto.getAuditTime() == null ? DateUtil.getCurrentDatetime() : auditCommitResDto.getAuditTime());
    updateWrapper.set("audit_id", auditCommitResDto.getAuditId());
    updateWrapper.set("audit_state", auditCommitResDto.getAuditState());
}
if (AuditActionEnum.approveReject.getKey().equals(auditAction)) {
    updateWrapper.set("is_master", EffectMasterEnum.master.getKey());
    updateWrapper.set("is_effective", EffectMasterEnum.un_effect.getKey());
    updateWrapper.set("audit_time", auditCommitResDto.getAuditTime() == null ? DateUtil.getCurrentDatetime() : auditCommitResDto.getAuditTime());
    updateWrapper.set("audit_state", auditCommitResDto.getAuditState());
    updateWrapper.set("audit_id", auditCommitResDto.getAuditId());
}

 

写完之后觉得不妥 太多 if else

改为 使用策略模式：

 

 策略接口：

@Component
public interface IAuditStrategy {
   void doAction(IService service , Long id , AuditCommitResDto auditCommitResDto);
}

@Component("commit")
public class CommitAuditStrategy implements IAuditStrategy {
    @Override
    public void doAction(IService service, Long id, AuditCommitResDto auditCommitResDto) {
        service.update(new UpdateWrapper<>()
                .set("audit_id", auditCommitResDto.getAuditId())
                .set("commit_time", auditCommitResDto.getCommitTime())
                .set("audit_state", auditCommitResDto.getAuditState())
                .eq("id", id)
        );
    }
}

具体实现子类：

@Component("approvePass")
public class ApprovePassAuditStrategy implements IAuditStrategy {
    @Override
    public void doAction(IService service, Long id, AuditCommitResDto auditCommitResDto) {
        //审核通过先把之前数据失效 ，在把通过的这条生效
        service.update(new UpdateWrapper<>()
                .set("is_effective", EffectMasterEnum.effect.getKey())
                .eq("master_id", id)
        );
        service.update(new UpdateWrapper<>()
                .set("is_effective", EffectMasterEnum.effect.getKey())
                .set("audit_time", auditCommitResDto.getAuditTime())
                .set("audit_state", auditCommitResDto.getAuditState())
                .eq("id", id)

        );
    }
}

 

 

通过 ioc 容器注入 并调用：

 

@Autowired
private Map<String, IAuditStrategy> auditStrategyMap;


调用代码：

auditStrategyMap.get(dto.getAuditAction()).doAction(this,id,auditCommitResDto);

 

 ======================================================================================= 经好友提示直接使用 String 作为策略的key容易与其他bean 冲突  所以使用 枚举类作为 key较好，这里引用 

ApplicationContextAware 
好处是不用重新 加载一遍 上下文 applicationContext （如直接用  

ApplicationContext appContext = new ClassPathXmlApplicationContext("applicationContext-common.xml");  
AbcService abcService = (AbcService)appContext.getBean("abcService");  

因为它会重新装载applicationContext-common.xml并实例化上下文bean，如果有些线程配置类也是在这个配置文件中，那么会造成做相同工作的的线程会被启两次。一次是web容器初始化时启动，另一次是上述代码显示的实例化了一次。当于重新初始化一遍！！！！这样就产生了冗余。

）
所以新增一个工厂类 去注册策略的生成

@Component
public class IAuditStrategyFactory implements ApplicationContextAware {
    private Map<AuditActionEnum, IAuditStrategy> iAuditActionStateMap = new ConcurrentHashMap<>();
    public IAuditStrategy getStrategy(AuditActionEnum auditActionEnum) {
        return iAuditActionStateMap.get(auditActionEnum);
    }

    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        Map<String, IAuditStrategy> map = applicationContext.getBeansOfType(IAuditStrategy.class);
        for(Map.Entry<String, IAuditStrategy> entry:map.entrySet()){
            iAuditActionStateMap.put(AuditActionEnum.match(entry.getKey()), entry.getValue());
        }
    }
}