easy-poi 导出大量数据

第一步：引入依赖

			cn.afterturn
			easypoi-base
			4.0.0
		
		
			cn.afterturn
			easypoi-web
			4.0.0
		
		
			cn.afterturn
			easypoi-annotation
			4.0.0
		

第二步：

@GetMapping(value = "/exportAllSalesRecordSellIn")
    public void exportAllSalesRecordSellIn(HttpServletResponse response) throws Exception {
        Long t1 = System.currentTimeMillis();
        System.out.println();
        Map paramsMap = new HashMap<>();
        paramsMap.put("page","1");paramsMap.put("limit","20000");
        ExportParams params = new ExportParams("销售数据统计", "销售数据");
        Workbook workbook = null;
        PageData allSalesRecordSellIn = midSalesRecordSellInService.getAllSalesRecordSellIn(paramsMap);
        int totalPage = (int)Math.ceil((double)allSalesRecordSellIn.getTotal()/20000);
        for(int currentPage = 1; currentPage <= totalPage; currentPage++){
            paramsMap.put("page",String.valueOf(currentPage));
            Long l1 = System.currentTimeMillis();
            PageData mr = midSalesRecordSellInService.getAllSalesRecordSellIn(paramsMap);
            Long l2 = System.currentTimeMillis();
            System.out.println("查询"+currentPage+"耗时:"+(l2-l1)/1000+"秒");
            workbook = ExcelExportUtil.exportBigExcel(params, Mid_salesRecordSellIn.class, mr.getList());
        }
        ExcelExportUtil.closeExportBigExcel();

        String fileName = "saleData.xlsx";
        //告诉浏览器下载excel
        downloadExcel(fileName, workbook, response);
        Long t2 = System.currentTimeMillis();
        System.out.println("总共耗时:"+(t2 - t1)/1000+"秒");
    }

    protected void downloadExcel(String filename, Workbook workbook, HttpServletResponse response) throws Exception {
        response.setContentType("application/vnd.ms-excel");
        response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(filename, "utf-8"));
        OutputStream outputStream = response.getOutputStream();
        workbook.write(outputStream);
        outputStream.flush();
        outputStream.close();
    }

数据量非常大时，采用分页查询，分为多次写入，以免内存溢出。