优化页面导出功能

矫情吗；* 2022-11-11 05:15 90阅读 0赞

某天运营人员想导出公司的结算数据

![20210323180610182.png][]

等了几千年，最终报错了

![20210319121427377.png][]

然后她去群里召唤我，双方经过激烈的争执

![20210323181024785.png][]

我改，我改还不行吗！！！

# 1 定位问题 #

通过 arthas 定位，发现主要慢在部分方法通过 id 单个调用dubbo接口或查询数据库

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d5ZHlkMTEw_size_16_color_FFFFFF_t_70][]

# 2 解决方案 #

**（1）**通过 id 单个查询改为通过 ids 批量查询数据库

**（2）**列表串行遍历改为并行流遍历

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d5ZHlkMTEw_size_16_color_FFFFFF_t_70 1][]

**（3）**分批并行组装数据

原来

public List<BillingRecordsDTO> convertToDto(List<BillingRecordsBean> list, boolean isAdmin, Integer announcerType, boolean needPhotoUrl) {
    	  
         return this.billingManager.convertToDto(list, isAdmin,announcerType, false);
    }

修改后

public List<BillingRecordsDTO> convertToDto(List<BillingRecordsBean> list, boolean isAdmin, Integer announcerType, boolean needPhotoUrl) {
    			
         // 1000 条分片
         List<List<BillingRecordsBean>> partitionList = Lists.partition(list, 1000);
         List<BillingRecordsDTO> collect = partitionList
                // 并行流 公共 ForkJoinPool
                .parallelStream()
                // 使用 CompletableFuture 返回结果
                .map(billingRecordsBeanList -> CompletableFuture.supplyAsync(() -> this.billingManager.convertToDto(billingRecordsBeanList, isAdmin,announcerType, false)))
                // 获取结果
                .map(CompletableFuture::join)
                // List<List> 转为 流
                .flatMap(List::stream)
                .collect(Collectors.toList());
          return collect;  
    }

[20210323180610182.png]: /images/20221022/1031bbe6442f473ababd0a1faa5d8448.png
[20210319121427377.png]: https://img-blog.csdnimg.cn/20210319121427377.png
[20210323181024785.png]: https://img-blog.csdnimg.cn/20210323181024785.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d5ZHlkMTEw_size_16_color_FFFFFF_t_70]: https://img-blog.csdnimg.cn/20210323181311691.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d5ZHlkMTEw,size_16,color_FFFFFF,t_70
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d5ZHlkMTEw_size_16_color_FFFFFF_t_70 1]: https://img-blog.csdnimg.cn/20210323182200354.png?x-oss-process=image/watermark,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3d5ZHlkMTEw,size_16,color_FFFFFF,t_70