SpringBoot实现文件的上传和下载

@RequestMapping(value = "/upload", method = RequestMethod.POST)
@ResponseBody
public String upload(@RequestParam MultipartFile file) throws IOException {
    File fileObj = new File("test.png");
    file.transferTo(fileObj);
    System.out.println("用户上传的文件已保存到："+fileObj.getAbsolutePath());
    return "文件上传成功！";
}

<div>
    <form action="upload" method="post" enctype="multipart/form-data">
        <input type="file" name="file">
        <input type="submit">
    </form>
</div>

@RequestMapping(value = "/download", method = RequestMethod.GET)
@ResponseBody
public void download(HttpServletResponse response){
    response.setContentType("multipart/form-data");
    try(OutputStream stream = response.getOutputStream();
        InputStream inputStream = new FileInputStream("test.png")){
        IOUtils.copy(inputStream, stream);
    }catch (IOException e){
        e.printStackTrace();
    }
}

<a href="download" download="test.png">下载最新资源</a>