代码优雅之道——用统一风格的模式演绎秒杀系统程序设计

前言

看过老版《三国演绎》的都知道，这部历史题材的鸿篇巨制获得巨大成功，除了演员的精湛演技，导演的匠心制作，忠于原著的文白式的历史还原，还有就是统一的演绎风格————统一的道具，统一服装，统一的场景布局，统一摄制......这些统一的演绎风格，正是电视剧的优雅之处!

代码的优雅之道也是如此，只要有统一的编程风格和模式，程序也是一道靓丽的风景！

优雅代码模板设计

VO、DTO、DO使用

VO：前端传输使用主要应用于business服务中的Controller类

DTO：业务聚合服务调用原子服务时使用,多为原子服务Controller类的请求参数和返回结果

DO：数据映射类Mapper类使用 

服务调用约定

服务方返回：Response<T>

示例：

@RequestMapping(value = MemberConstants.MEMBER_AUTH_LONGINFO_REQ_PATH, method = RequestMethod.POST)
public Response<AuthUserRspDTO> getAuthUser(@RequestParam(value = "phone", required = true)String phone){
     String serviceName = "AuthQryController.getAuthUser";
     return webActionTemplate.execute(new AbstractWebAction<AuthUserRspDTO, String>(serviceName,phone) {
            @Override
            public void validateParams(String param) throws BizException {
                  AuthQryValidator.doValidQryParam(param);
            }

            @Override
            public AuthUserRspDTO doAction(String param) throws BizException {
                 AuthUserBO authUserBO = authUserQryService.getAuthUser(param);
                 AuthUserRspDTO rspDTO = AuthUserConvertor.bo2DTO(authUserBO);
                 return rspDTO;
            }
     });
 }

调用方处理：

public AuthUserRspDTO getAuthUser(String phone) {
     Response<AuthUserRspDTO> rspRst = authRemote.getAuthUser(phone);
     if(rspRst == null){
            throw new RuntimeException("用户服务获取认证用户信息远程调用返回异常");
     }

    if(!rspRst.isSuccess()){
           throw new RuntimeException("用户服务获取认证用户信息远程调用失败");
    }

    return rspRst.getData();
}



常见的业务处理步骤可参考如下，实际处理根据业务需要酌情修改                

public Integer createAuth(AuthUserBO userBo) {
     Map<String, Object> bizData = new HashMap<>();
     //业务验证
     doVaildAuth(userBo, bizData);
     //防重验证
     doCheckRepeat(userBo);
     //组装处理数据
     doHandleData(userBo, bizData);
     //三方服务调用
     doInvokeRemote(userBo, bizData);
     //数据库处理
     doCommitDBAuth(bizData);
     //事件发送
     doPublishEvent(bizData);
     return SUCCESS_CODE;
}



2.3.4 通用的业务处理模板可参考如下，实际处理根据业务需要酌情修改

public FacadeResponse doTrigger(FacadeRequest req) {
     FacadeResponse response = new FacadeResponse();
     Map<String,Object> bizMap = new HashMap<>();
     //参数验证
     doCheck(req);
     //防重验证
     boolean reapet = doRepeat(req);
     if(reapet){
         response.setSuccess(true);
         logger.info("[AbstractActionFacade.doReapet] request:{},response:{}"
              ,JSON.toJSONString(req),JSON.toJSONString(response));
         return response;
     }
     //业务验证
     boolean checkBizRst = doCheckBiz(req,bizMap);
     if(!checkBizRst){
         response.setSuccess(false);
         logger.info("[AbstractActionFacade.doCheckBiz] check fail request:{},response:{}"
             , JSON.toJSONString(req),JSON.toJSONString(response));
         return response;
     }
     try {
         //数据组装
         doAssemble(req, bizMap);
         //三方调用
         doInvokeRemote(req, bizMap);
         //数据库提交
         transactionTemplate.execute(new TransactionCallbackWithoutResult() {
             @Override
             protected void doInTransactionWithoutResult(TransactionStatus status) {
                 doCommitDatabase(req, bizMap);
             }
         });
         //发布事件
         doPublishEvent(req, bizMap);
         //通知
         doNotify(req, bizMap);
         response.setSuccess(true);
      }catch (BizException ex) {
         doPublishErrorEvent(req, bizMap);
         response.setSuccess(false);
         logger.error("[AbstractActionFacade.BizException] message:{}", ExceptionTracker.trace(ex));
         throw ex;
      }catch (TransactionSystemException ex){
         logger.error("[AbstractActionFacade.TransactionSystemException] transaction error message:{}",ExceptionTracker.trace(ex));
         throw new BizException(SysCodeEnum.DB_TRANSACTION_ERROR);
      }catch (RuntimeException ex){
         doPublishErrorEvent(req, bizMap);
         response.setSuccess(false);
         logger.error("[AbstractActionFacade.RuntimeException] message:{}",ExceptionTracker.trace(ex));
         throw ex;
      }catch (Exception ex){
         doPublishErrorEvent(req, bizMap);
         response.setSuccess(false);
         logger.error("[AbstractActionFacade.Exception] message:{}",ExceptionTracker.trace(ex),ex);
         throw ex;
      }
      return response;
 }

protected abstract boolean doRepeat(FacadeRequest req) throws BizException;

protected abstract boolean doCheckBiz(FacadeRequest req,Map<String,Object> bizMap)throws BizException;

protected abstract void doAssemble(FacadeRequest req,Map<String,Object> bizMap)throws BizException;

protected abstract void doInvokeRemote(FacadeRequest req,Map<String,Object> bizMap)throws BizException;

protected abstract void doCommitDatabase(FacadeRequest req,Map<String,Object> bizMap)throws BizException;

protected abstract void doPublishEvent(FacadeRequest req,Map<String,Object> bizMap)throws BizException;

protected abstract void doNotify(FacadeRequest req,Map<String,Object> bizMap)throws BizException;

protected abstract void doPublishErrorEvent(FacadeRequest req,Map<String,Object> bizMap);

秒杀系统设计

秒杀系统的代码优雅实现

源代码

参考