完整的文件下载例子

淡淡的烟草味﹌ 2022-02-02 18:29 174阅读 0赞

前段，js 下载

1，采用ajax异步调用，后台生成文件，返回前段，文件的名称

2，文件名称采用唯一的UUID生成

后端处理

@ResponseBody
    	@RequestMapping(value = "ajaxExport")
    	public Map<String, Object> exportFile( @RequestParam Map<String, Object> parameters, HttpServletRequest request, HttpServletResponse response,
    			RedirectAttributes redirectAttributes) {
    		boolean ok = false;
    		String fileId = IdGen.uuid();
    		String ext = null;
    		// 获取有效数据
    		List<MapEntity> datas = xzcfToDoService.findFeedList(parameters);
    		try {
    			// 生成对应的excel文件
    			File file = xzcfToDoService.createPushExcel(datas, fileId);
    			if (file != null) {
    				ok = true;
    				ext = Files.getFileExtension(file.getName());
    			}
    		} catch (IOException e) {}
    		// 返回ajax 数据
    		Map<String, Object> result = Maps.newHashMap();
    		result.put("ok", ok);
    		result.put("fileId", fileId);
    		result.put("ext", ext);
    		return result;
    	}

@Transactional(readOnly = false)
    	public File createPushExcel(List<MapEntity> entities,String fileId) throws IOException {
    		// 1. 生成一个file 文件
    		File resultFile  = null;
    		try {
    			if(StringUtils.isBlank(fileId)){
    				fileId = IdGen.uuid();
    			}
    			String[] headers = {"主体名称"};
    			String[] keys = {"cfxdrmc"};
    			
    			ExportExcel  ex =new ExportExcel("行政处罚反馈数据", headers).setDataList1(entities, keys);
    			String tmpPath = DataUtils.getServletContextRealPathResolver().get(Global.getConfig("tmpPath"));
    			File dir = new File(tmpPath);
    			if (!dir.exists()) {
    				dir.mkdirs();
    			}
    			resultFile = new File(tmpPath + "/" + fileId + ".xls");
    			FileOutputStream os = new FileOutputStream(resultFile);
    			ex.write(os);
    			os.flush();
    			os.close();
    			
       	   } catch (Exception e) {
       		   e.printStackTrace();
       	   }
    		   return resultFile;
    	  }

下载代码，

URLEncoder.encode 编码，防止，下载中文乱码

@RequestMapping("download")
    	public String download(String fileId, String ext, HttpServletRequest request, HttpServletResponse response) {
    		try {
    			response.reset();
    			response.setContentType("application/octet-stream");
    			String fileName = URLEncoder.encode(xzcfName+"."+ext, "utf-8");
    			String tmpPath = DataUtils.getServletContextRealPathResolver().get(Global.getConfig("tmpPath"));
    			File file = new File(tmpPath + "/" + fileId + "." + ext);
    			System.out.println(file.exists());
    			InputStream is = new FileInputStream(file);
    			OutputStream os = response.getOutputStream();
    			response.addHeader("Content-Disposition", "attachment; filename=\""+ fileName +"\""); 
    			IOUtils.copy(is, os);
    		} catch (IOException e) {
    			e.printStackTrace();
    		}
    		return null;
    	}