在springmvc项目中使用poi导入导出excel

 <form name="excelImportForm" action="${pageContext.request.contextPath}/brand/importBrandSort" method="post" onsubmit="return checkImportPath();" enctype="multipart/form-data" id="excelImportForm">
                <input  type="hidden" name="ids" id="ids">
                <div class="modal-body">
                    <div class="row gap">
                        <label class="col-sm-7 control-label"><input class="btn btn-default" id="excel_file" type="file" name="filename"  accept="xls"/></label>
                        <div class="col-sm-3">
                            
                        	<input class="btn btn-primary" id="excel_button" type="submit" value="导入Excel"/>
                        </div>
                    </div>
                    
                </div>
               
                <div class="modal-footer">
						<button type="button" class="btn btn-default" data-dismiss="modal" onClick="uncheckBoxes();">取消</button>
				</div>

@RequestMapping(value = "/importBrandSort", method = RequestMethod.POST)
	public ModelAndView importBrandSort(@RequestParam("filename") MultipartFile file,
			HttpServletRequest request,HttpServletResponse response) throws Exception {
		String temp = request.getSession().getServletContext()
				.getRealPath(File.separator)
				+ "temp"; // 临时目录
		File tempFile = new File(temp);
		if (!tempFile.exists()) {
			tempFile.mkdirs();
		}
		DiskFileUpload fu = new DiskFileUpload();
		fu.setSizeMax(10 * 1024 * 1024); // 设置允许用户上传文件大小,单位:位
		fu.setSizeThreshold(4096); // 设置最多只允许在内存中存储的数据,单位:位
		fu.setRepositoryPath(temp); // 设置一旦文件大小超过getSizeThreshold()的值时数据存放在硬盘的目录
		// 开始读取上传信息
		// int index = 0;
	/*	List fileItems = null;
		try {
			fileItems = fu.parseRequest(request);
		} catch (Exception e) {
			e.printStackTrace();
		}
		Iterator iter = fileItems.iterator(); // 依次处理每个上传的文件
		FileItem fileItem = null;
		while (iter.hasNext()) {
			FileItem item = (FileItem) iter.next();// 忽略其他不是文件域的所有表单信息
			if (!item.isFormField()) {
				fileItem = item;
				// index++;
			}
		}
		
		if (fileItem == null)
			return null;
			*/
		if (file == null)
			return null;
		logger.info(file.getOriginalFilename());
		
		String name = file.getOriginalFilename();// 获取上传文件名,包括路径
		//name = name.substring(name.lastIndexOf("\\") + 1);// 从全路径中提取文件名
		long size = file.getSize();
		if ((name == null || name.equals("")) && size == 0)
			return null;
		InputStream in = file.getInputStream();
		List<BrandMobileInfoEntity> BrandMobileInfos = brandService
				.importBrandPeriodSort(in);

		// 改为人工刷新缓存KeyContextManager.clearPeriodCacheData(new
		// PeriodDimensions());// 清理所有缓存
		int count = BrandMobileInfos.size();
		String strAlertMsg ="";
		if(count!=0){
			strAlertMsg= "成功导入" + count + "条！";
		}else {
			strAlertMsg = "导入失败！";
		}
		logger.info(strAlertMsg);
		//request.setAttribute("brandPeriodSortList", BrandMobileInfos);
		//request.setAttribute("strAlertMsg", strAlertMsg);
	
		request.getSession().setAttribute("msg",strAlertMsg);
		return get(request, response);
		//return null;
	}

InputStream in = file.getInputStream();
		List<BrandMobileInfoEntity> BrandMobileInfos = brandService
				.importBrandPeriodSort(in);

@Override
	public List<BrandMobileInfoEntity> importBrandPeriodSort(InputStream in) throws Exception  {
		
		List<BrandMobileInfoEntity> brandMobileInfos = readBrandPeriodSorXls(in);
		for (BrandMobileInfoEntity brandMobileInfo : brandMobileInfos) {
			mapper.updateByConditions(brandMobileInfo);
		}
		return brandMobileInfos;
	}

$(".exportBrandSort").on('click', function() {
    	
    	 var url = contextPath+"/brand/exportBrandSort";
    	 $('#searchform').attr('action', url);
    	 $('#searchform').submit();
    	 //还原action值
    	 url = contextPath+"/brand/getBrand";
    	 $('#searchform').attr('action', url);<span style="font-family: 'Microsoft YaHei UI', 'Microsoft YaHei', SimSun, 'Segoe UI', Tahoma, Helvetica, sans-serif, 'Microsoft YaHei', Georgia, Helvetica, Arial, sans-serif, 宋体, PMingLiU, serif; font-size: 14px;">}</span>

@RequestMapping(value = "/exportBrandSort", method = RequestMethod.GET)
	public void exportBrandSort(HttpServletRequest request,
			HttpServletResponse response) throws Exception {

		try {
			Map<String, Object> params = new HashMap<>();
			// start time of selling
			String startTimeStr = RequestUtil.getStringParameter(request,
					"startTimeStr", null);
			if (StringUtils.isNotBlank(startTimeStr)) {
				params.put("startTimeStr", startTimeStr);
				params.put("startTime", df.parse(startTimeStr).getTime() / 1000);
			}

			// end time of selling
			String endTimeStr = RequestUtil.getStringParameter(request,
					"endTimeStr", null);
			if (StringUtils.isNotBlank(endTimeStr)) {
				params.put("endTimeStr", endTimeStr);
				params.put("endTime", df.parse(endTimeStr).getTime() / 1000);
			}

			// warehouse
			String warehouse = RequestUtil.getStringParameter(request,
					"warehouse");
			if (StringUtils.isNotBlank(warehouse)) {
				params.put("warehouse", warehouse);
			}

			// channel
			String channel4ui = BrandConstants.CHANNEL_ID_SEARCH_DEFAULT;

			String[] channel = request.getParameterValues("channel");
			if (channel != null && channel.length > 0) {
				channel4ui = stringArrayToString(channel);
			}
			params.put("channel", channel4ui);

			String orderType = request.getParameter("orderType");
			if (orderType == null || "".equals(orderType)) {
				orderType = "C";
			}
			params.put("orderType", orderType);

			// brand id
			if (RequestUtil.getIntParameter(request, "brandId") > 0)
				params.put("brandId",
						(RequestUtil.getIntParameter(request, "brandId")));
			// brand name
			if (RequestUtil.getStringParameter(request, "brandName") != null
					&& !"".equals(RequestUtil.getStringParameter(request,
							"brandName").trim()))
				// params.put("brandName", new
				// String(RequestUtil.getStringParameter(request,
				// "brandName").getBytes("ISO-8859-1"),"UTF-8"));
				params.put("brandName",
						RequestUtil.getStringParameter(request, "brandName"));

			int count = brandService.countByConditions(params);

			List<BrandCompleteInfoEntity> list = brandService
					.queryBrands(params);

			// --------

			byte[] fileNameByte = ("kxw.xls").getBytes("GBK");
			String filename = new String(fileNameByte, "ISO8859-1");

			byte[] bytes = brandService.exportBrandPeriodSort(list);
		//	logger.info("------------------------"+bytes.length);
			response.setContentType("application/x-msdownload");
			//response.setContentType("application/x-excel");  
			response.setContentLength(bytes.length);
			response.setHeader("Content-Disposition", "attachment;filename="
					+ filename);
			response.getOutputStream().write(bytes);
			//response.getOutputStream().flush();
			
		   
		} catch (Exception ex) {
			logger.debug(ex.getMessage());
		}
	}

byte[] fileNameByte = ("档期列表.xls").getBytes("GBK");
			String filename = new String(fileNameByte, "ISO8859-1");

			byte[] bytes = brandService.exportBrandPeriodSort(list);

@Override
	public byte[] exportBrandPeriodSort(List<BrandCompleteInfoEntity>  list) throws Exception {
		
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		// 第一步，创建一个webbook，对应一个Excel文件
		HSSFWorkbook wb = new HSSFWorkbook();
		// 第二步，在webbook中添加一个sheet,对应Excel文件中的sheet
		HSSFSheet sheet = wb.createSheet("档期排序表");
		// 第三步，在sheet中添加表头第0行,注意老版本poi对Excel的行数列数有限制short
		HSSFRow row = sheet.createRow((int) 0);
		// 第四步，创建单元格，并设置值表头 设置表头居中
		HSSFCellStyle style = wb.createCellStyle();
		style.setAlignment(HSSFCellStyle.ALIGN_CENTER); // 创建一个居中格式

		//设置表头
		List<String> excelHead = getExcelHead();
		
		HSSFCell cell = null;
		// excel头
		for (int i = 0; i < excelHead.size(); i++) {
			cell = row.createCell(i);
			cell.setCellValue(excelHead.get(i));
			cell.setCellStyle(style);
		}

		// 第五步，写入实体数据 实际应用中这些数据从数据库得到
		//List<BrandPeriodSortEntity> list = getBrandPeriodSortDynamicOrder(entity, orderType);

		BrandCompleteInfoEntity brandCompleteInfo = null; // 拼装excel内容
		for (int i = 0; i < list.size(); i++) {
			row = sheet.createRow((int) i + 1);
			brandCompleteInfo = list.get(i);
			// 创建单元格，并设置值
		
			
			int j=0;
			insertCell(row, j++, brandCompleteInfo.getBrandId());
			insertCell(row, j++, brandCompleteInfo.getBrandName());
			insertCell(row, j++, brandCompleteInfo.getMobileShowFrom());
			insertCell(row, j++, brandCompleteInfo.getMobileShowTo());
			insertCell(row, j++, brandCompleteInfo.getSellMarkValue());
			insertCell(row, j++, brandCompleteInfo.getWarehouse());
			insertCell(row, j++, brandCompleteInfo.getSortA1());
			insertCell(row, j++, brandCompleteInfo.getSortA2());
			insertCell(row, j++, brandCompleteInfo.getSortB());
			insertCell(row, j++, brandCompleteInfo.getSortC10());
			insertCell(row, j++, brandCompleteInfo.getSortC());
			insertCell(row, j++, brandCompleteInfo.getHitA());
			insertCell(row, j++, brandCompleteInfo.getHitB());
			insertCell(row, j++, brandCompleteInfo.getHitC());
			insertCell(row, j++, brandCompleteInfo.getCustomSellType());
			insertCell(row, j++, channelInfoMapper.loadChannelNameById(brandCompleteInfo.getChannelId()));
			insertCell(row, j++, brandCompleteInfo.getChannelId());
			
		}
		wb.write(out);
		return out.toByteArray();
	}
	
	/**
	 * 获取excel表头
	 * 
	 * @return
	 */
	private List<String> getExcelHead() {
		List<String> result = new ArrayList<String>(17);
		result.add("XXXXX");
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<pre name="code" class="java" style="font-size: 14.44444465637207px; line-height: 21px;"><span style="white-space:pre">		</span>result.add("XXXXX");
<pre name="code" class="java"><span>		</span>result.add("XXXXX");

<pre name="code" class="java" style="font-size: 14.44444465637207px; line-height: 21px;"><span style="white-space:pre">		</span>result.add("XXXXX");
<pre name="code" class="java"><span>		</span>result.add("XXXXX");

<span>		</span>result.add("XXXXX");
<pre name="code" class="java"><span>		</span>result.add("XXXXX");