SpringBoot实现文件上传下载功能小结

// 单文件上传@RequestMapping(value = "/upload")@ResponseBodypublic String upload(@RequestParam("file") MultipartFile file) {  try {  if (file.isEmpty()) {    return "文件为空";  }  // 获取文件名  String fileName = file.getOriginalFilename();  logger.info("上传的文件名为：" + fileName);  // 获取文件的后缀名  String suffixName = fileName.substring(fileName.lastIndexOf("."));  logger.info("文件的后缀名为：" + suffixName);  // 设置文件存储路径  String filePath = "D://aim//";  String path = filePath + fileName + suffixName;  File dest = new File(path);  // 检测是否存在目录  if (!dest.getParentFile().exists()) {    dest.getParentFile().mkdirs();// 新建文件夹  }  file.transferTo(dest);// 文件写入  return "上传成功";  } catch (IllegalStateException e) {    e.printStackTrace();  } catch (IOException e) {    e.printStackTrace();  }  return "上传失败";}

//多文件上传@RequestMapping(value = "/uploadMore", method = RequestMethod.POST)@ResponseBodypublic String handleFileUpload(HttpServletRequest request) {  List<MultipartFile> files = ((MultipartHttpServletRequest) request).getFiles("file");  MultipartFile file = null;  BufferedOutputStream stream = null;  for (int i = 0; i < files.size(); ++i) {    file = files.get(i);    String filePath = "D://aim//";    if (!file.isEmpty()) {      try {        byte[] bytes = file.getBytes();        stream = new BufferedOutputStream(new FileOutputStream(            new File(filePath + file.getOriginalFilename())));//设置文件路径及名字        stream.write(bytes);// 写入        stream.close();      } catch (Exception e) {        stream = null;        return "第 " + i + " 个文件上传失败 ==> "            + e.getMessage();      }    } else {      return "第 " + i          + " 个文件上传失败因为文件为空";    }  }  return "上传成功";}

//文件下载相关代码@RequestMapping("/download")public String downloadFile(HttpServletRequest request, HttpServletResponse response) {  String fileName = "aim_test.txt";// 设置文件名，根据业务需要替换成要下载的文件名  if (fileName != null) {    //设置文件路径    String realPath = "D://aim//"    File file = new File(realPath , fileName);    if (file.exists()) {      response.setContentType("application/force-download");// 设置强制下载不打开      response.addHeader("Content-Disposition", "attachment;fileName=" + fileName);// 设置文件名      byte[] buffer = new byte[1024];      FileInputStream fis = null;      BufferedInputStream bis = null;      try {        fis = new FileInputStream(file);        bis = new BufferedInputStream(fis);        OutputStream os = response.getOutputStream();        int i = bis.read(buffer);        while (i != -1) {          os.write(buffer, 0, i);          i = bis.read(buffer);        }        System.out.println("success");      } catch (Exception e) {        e.printStackTrace();      } finally {        if (bis != null) {          try {            bis.close();          } catch (IOException e) {            e.printStackTrace();          }        }        if (fis != null) {          try {            fis.close();          } catch (IOException e) {            e.printStackTrace();          }        }      }    }  }  return null;}

@Configurationpublic class MultipartConfig {  @Bean  public MultipartConfigElement multipartConfigElement() {    MultipartConfigFactory factory = new MultipartConfigFactory();    // 置文件大小限制 ,超出此大小页面会抛出异常信息    factory.setMaxFileSize("2MB"); //KB,MB    // 设置总上传数据总大小    factory.setMaxRequestSize("20MB");    // 设置文件临时文件夹路径    // factory.setLocation("E://test//");    // 如果文件大于这个值，将以文件的形式存储，如果小于这个值文件将存储在内存中，默认为0    // factory.setMaxRequestSize(0);    return factory.createMultipartConfig();  }}