CSV导出

1.依赖jar包

<dependency>
    <groupId>net.sourceforge.javacsv</groupId>
    <artifactId>javacsv</artifactId>
    <version>2.0</version>
</dependency>
2.导出实现

 public void export(QmsInspectionTaskReqDTO reqDTO, HttpServletRequest request, HttpServletResponse response) {
        QmsAssert.notNull(reqDTO,"参数为空");
        QmsResponseResult< Map<Long,List<ExportTaskResDTO>>> responseResult = taskRpcService.selectList(reqDTO);
        long startTime = System.currentTimeMillis();
        if (responseResult.getCode() == 999) {
            throw new QmsException(999,"导出条数超过限制");
        }
        if (responseResult.getCode() != 200) {
            throw new QmsParamException("查询失败");
        }
        //导出
        String destFileName = "入库质检任务";
        // CSV写对象
        BufferedWriter buffCvsWriter = null;
        CsvWriter csvWriter=null;
        ServletOutputStream  out=null;
        response.setContentType("application/vnd.ms-excel;charset=utf-8");
        try{
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(destFileName,"UTF8") + "-" + DateUtil.getCurrTimestamp() + ".csv");
              out = response.getOutputStream();
            buffCvsWriter = new BufferedWriter(new OutputStreamWriter(out, "GBK"));
            csvWriter = new CsvWriter(buffCvsWriter, ',');
            // 表头
            String[] headers = { "质检任务ID", "仓库", "质检环节", "采购单号", "采购单行号", "采购类型","下单量","到货量","抽检量","物理单位","计价单位","入库单号","入库单单行号","质检时间","供应商","质检商品","采销一级分类","采销二级分类","采销三级分类","生产日期","保质期（天）","质检员","操作（处理动作）","质检任务状态","质检结果","综合货损%","明细","备注"};
            csvWriter.writeRecord(headers,true);
            // 第一层for循环 按照主表来分类
            Map<Long,List<ExportTaskResDTO>>  resultMap= responseResult.getData();
            for(Map.Entry<Long,List<ExportTaskResDTO>> entry : resultMap.entrySet()){
                ListIterator iterator=   entry.getValue().listIterator();
                StringBuilder sb = new StringBuilder("");
                ExportTaskResDTO one = null;
                boolean hasDone = false;
                int count  = 1;
                while (iterator.hasNext()){
                    ExportTaskResDTO item = null;
                    if (!hasDone) {
                        one = (ExportTaskResDTO) iterator.next();
                        item = one;
                        hasDone = true;
                        /**
                         * 共有数据处理
                         */
                        // 任务ID
                        one.setIdString(one.getId().toString());
                        // 采购单号
                        one.setPurchaseOrderString(one.getPurchaseOrder().toString());
                        // 采购单行号
                        one.setPurchaseOrderItemString(one.getPurchaseOrderItem().toString());
                        // 入库单行号
                        one.setInstockOrderItemString(one.getInstockOrderItem().toString());

                        // 质检环节
                        one.setInspectionLinkName(InspectionLinkEnum.getName(one.getInspectionLink()));
                        // 任务状态
                        one.setTaskStatusName(TaskStatusEnum.getName(one.getTaskStatus()));
                        // 质检时间
                        if (one.getInspectionStartTime() != null) {
                            one.setInspectionTime(DateUtil.format(one.getInspectionStartTime(),DateUtil.YYYY_MM_DD));
                        }
                        // 质检结果
                        one.setInspectionResultName(ActResultEnum.getName(one.getInspectionResult()));
                        // 操作
                        one.setDealStatusName(Event.getName(one.getDealStatus()));
                        // 综合货损
                        one.setMultipleDamageValString(one.getMultipleDamageVal().toString()+"%");
                        // 采购类型
                        one.setTypeString(PurchaseTypeEnum.getNameByIndex(one.getType()));

                        // TODO: 2019/10/31  暂缺 入库类型，渠道

                    }else {
                        item = (ExportTaskResDTO) iterator.next();
                    }
                    /**
                     * 非共有数据 需要抽出到主表
                     */
                    // 生产日期 不一定是第一条数据，所以在下面判断
                    if (item.getArgType().equals(InspectionArgTypeEnum.DATE.getEnumValue()) && item.getInspectionItemsResult() !=null && !item.getInspectionItemsResult().isEmpty()) {
                        one.setProductionDate(DateUtil.format(new Date(Long.parseLong(item.getInspectionItemsResult())*1000),DateUtil.YYYY_MM_DD));
                    }
                    if (!item.getInspectionResult().equals(ActResultEnum.UN_INSPECTION.getEnumValue())){
                        sb.append(item.formatDetail(count));
                    }
                    count++;
                }
                one.setDetails(sb.toString());
                String[] content = {
                        "\t"+one.getIdString()+"\t",
                        "\t"+one.getWarehouseName()+"\t",
                        "\t"+one.getInspectionLinkName()+"\t",
                        "\t"+one.getPurchaseOrderString()+"\t",
                        "\t"+one.getPurchaseOrderItemString()+"\t",
                        "\t"+one.getTypeString()+"\t",
                        "\t"+one.getExpectNum()+"\t",
                        "\t"+one.getProductTotalNum()+"\t",
                        "\t"+one.getInspectionProductNum()+"\t",
                        "\t"+one.getPhysicalUnit()+"\t",
                        "\t"+one.getPriceUnit()+"\t",
                        "\t"+one.getInstockCode()+"\t",
                        "\t"+one.getInstockOrderItemString()+"\t",
                        "\t"+one.getInspectionTime()+"\t",
                        "\t"+one.getSupplierName()+"\t",
                        "\t"+one.getSkuName()+"\t",
                        "\t"+one.getPurchaseC1Name()+"\t",
                        "\t"+one.getPurchaseC2Name()+"\t",
                        "\t"+one.getPurchaseC3Name()+"\t",
                        "\t"+one.getProductionDate()+"\t",
                        "\t"+one.getShelfLife()+"\t",
                        "\t"+one.getInspectioner()+"\t",
                        "\t"+one.getDealStatusName()+"\t",
                        "\t"+one.getTaskStatusName()+"\t",
                        "\t"+one.getInspectionResultName()+"\t",
                        "\t"+one.getMultipleDamageValString()+"\t",
                        "\t"+one.getDetails()+"\t",
                        "\t"+one.getMark()+"\t",
                };
                csvWriter.writeRecord(content,true);
            }
            if(null != csvWriter) {
                csvWriter.close();
            }
        }catch (Exception  e){
            log.error(e.getMessage(), e);
            try {
                response.getWriter().write("data exception");
            } catch (IOException e1) {
                e1.printStackTrace();
            }
            return;
        }finally {
            if(null != csvWriter) {
                csvWriter.close();
            }
            try {
                if (null != buffCvsWriter) {
                    buffCvsWriter.close();
                }
                if (null != out) {
                    out.close();
                }
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        log.info("导出任务-明细处理+流处理花费时间="+(System.currentTimeMillis()-startTime)+"ms");
    }