事务用户指南

基础的使用方式在DataStore事务概述文章中已经描述过，核心就是在需要事务的业务逻辑上加一个@DSTransaction注解声明

1. 最佳实践

1.1 Flow/Function

1.1.1 接口定义上不需要声明事务（声明了也无效）

更新活动Flow声明

@Flow(name = "Update campaign")
public interface UpdateCampaignFlow {

    CampaignBO execute(CampaignBO campaignBO);

}

更新活动Function声明

@Function(name = "Update Campaign")
public interface UpdateCampaignFunc {

    CampaignBO execute(CampaignBO campaignBO);
}

1.1.2 实现上主动声明事务

更新活动Flow实现

@FlowImpl(name = "Update campaign")
@RequiredArgsConstructor
public class UpdateCampaignFlowImpl implements UpdateCampaignFlow {

    private final ValidateCampaignFunc validateCampaignFunc;
    private final UpdateCampaignFunc updateCampaignFunc;
    private final ValidateUpdateCampaignFunc validateUpdateCampaignFunc;
    private final OrganizationContext organizationContext;

    @DSTransaction
    @Override
    public CampaignBO execute(CampaignBO campaignBO) {
        if (Objects.isNull(campaignBO.getEntity())) {
            final EntityBO entityBO = organizationContext.getEntity();
            campaignBO.setEntity(entityBO);
        }
        validateCampaignFunc.execute(campaignBO);
        validateUpdateCampaignFunc.execute(campaignBO);
        final CampaignBO updatedCampaign = updateCampaignFunc.execute(campaignBO);
        return updatedCampaign;
    }
}

更新活动Function实现

@FunctionImpl(name = "Update Campaign")
@RequiredArgsConstructor
public class UpdateCampaignFuncImpl implements UpdateCampaignFunc {

    @DSTransaction
    @Override
    public CampaignBO execute(CampaignBO campaignBO) {
        if (!Objects.isNull(campaignBO.getCampaignFlowDefinition())) {
            if (!Objects.isNull(campaignBO.getCampaignFlowDefinition().getId())) {
                BooleanResult updateResult = DS.update(campaignBO.getCampaignFlowDefinition());
                if (!updateResult.getValue()) {
                    throw new BusinessException("update campaignFlowDefinition fail");
                }
            } else {
                IntResult createResult = DS.create(campaignBO.getCampaignFlowDefinition());
                campaignBO.setCampaignFlowDefinition(DS.findById(CampaignFlowDefinitionBO.class, createResult.getValue().longValue()));
            }
        }
        DS.update(campaignBO);
        return DS.findOne(CampaignBO.class, "*," + "campaignFlowDefinition.*", "id=?", campaignBO.getId());
    }
}

如果没有声明事务，可能出现预期外的结果，比如上面的更新活动Function，DS.create(campaignBO.getCampaignFlowDefinition())成功，但是DS.update(campaignBO);时候失败了，这时候这个function的执行结果就会出现一个中间状态，产生业务上非预期的数据。