JAVA - 大批量集合数据多线程处理

 原因：

最近写项目多时候遇到一个这样的问题，Excel批量导入表格，数据量较大，处理时间较长。然后小编想到了可以用多线程处理。

例：

                //导入失败集合
                List batchPayDetailExcelVoFailList = new CopyOnWriteArrayList<>();
                //导入成功集合
                List batchPayDetailExcelVoSuccessList = new CopyOnWriteArrayList<>();
                int totalSize = batchPayDetailList.size();   //总数量
                final int[] currentNum = {0};          //当前处理数量
/******************************************多线程处理开始*****************************************/
                // 一百条为基准为一个线程处理
                List> groupList = CommonUtils.partition(batchPayDetailList, 100);
                CountDownLatch countDownLatch = new CountDownLatch(groupList.size());
                ExecutorService executorService = Executors.newFixedThreadPool(groupList.size());

                for (int i = 0; i < groupList.size(); i++) {
                    int finalI = i;
                    executorService.execute(() -> {
                        List batchPayDetailGroup = groupList.get(finalI);
                        for (BatchPayDetailExcelDto batchPayDetailExcel : batchPayDetailGroup) {
                            currentNum[0]++;

                            //创建业务消息信息  -- 导入进度
                            JSONObject obj = new JSONObject();
                            obj.put("cmd", MyConstants.PREFIX_CMD_PAY);//业务类型
                            obj.put("msgId", merchantId);//消息id
                            obj.put("msgTxt", CommonUtils.proportionInt(currentNum[0], totalSize).replace("%", ""));//当前导入进度
//                            //单个用户发送 (userId为用户id)
                            webSocket.sendOneMessage(sysUser.getId(), obj.toJSONString());

                            String name = batchPayDetailExcel.getName();
                            String idCard = batchPayDetailExcel.getIdCard();
                            double money = batchPayDetailExcel.getFee();
                            if (!ValidUtil.validName(name.trim())) {
                                batchPayDetailExcel.setRemark("名字校验失败！");
                                batchPayDetailExcelVoFailList.add(batchPayDetailExcel);
                                continue;
                            }
                            if (!ValidUtil.validIdCardNo(idCard.trim())) {
                                batchPayDetailExcel.setRemark("身份证号校验失败！");
                                batchPayDetailExcelVoFailList.add(batchPayDetailExcel);
                                continue;
                            }
                            if (!ValidUtil.isNumber(money + "")) {
                                batchPayDetailExcel.setRemark("金额校验失败,仅支持精确到两位小数！");
                                batchPayDetailExcelVoFailList.add(batchPayDetailExcel);
                                continue;
                            }
                            if (money < 10) {
                                batchPayDetailExcel.setRemark("单笔代发交易金额不能低于10元！");
                                batchPayDetailExcelVoFailList.add(batchPayDetailExcel);
                                continue;
                            }
                            batchPayDetailExcelVoSuccessList.add(batchPayDetailExcel);
                        }
                        countDownLatch.countDown();
                    });
                }
                countDownLatch.await();
                executorService.shutdown();   //关闭线程池

注意：集合线程同步使用CopyOnWriteArrayList

工具类

 /**
     * 集合按长度分组
     *
     * @param list
     * @param size
     * @param 
     * @return
     */
    public static  List> partition(final List list, final int size) {
        if (list == null) {
            throw new IllegalArgumentException("List must not be null");


        }
        if (size <= 0) {
            throw new IllegalArgumentException("Size must be greater than 0");
        }
        List> result = new ArrayList<>();
        Iterator it = list.iterator();
        List subList = null;
        while (it.hasNext()) {
            if (subList == null) {
                subList = new ArrayList<>();
            }
            T t = it.next();
            subList.add(t);
            if (subList.size() == size) {
                result.add(subList);
                subList = null;
            }
        }
        //补充最后一页
        if (subList != null) {
            result.add(subList);
        }
        return result;

    }