使用SSM框架与layui实现文件上传与下载

文件上传与下载是Web应用程序中常用的功能，使用SSM框架与layui可以轻松实现这些功能。

1. 实现文件上传

（1）在页面中添加上传文件的表单

<form method="post" action="upload" enctype="multipart/form-data">
    <div class="layui-form-item">
        <label class="layui-form-label">上传文件</label>
        <div class="layui-input-block">
            <input type="file" name="file" lay-verify="required" class="layui-upload-file">
        </div>
    </div>
    <div class="layui-form-item">
        <div class="layui-input-block">
            <button class="layui-btn" lay-submit lay-filter="upload">上传</button>
        </div>
    </div>
</form>

（2）在Controller中处理上传请求

@RequestMapping("/upload")
@ResponseBody
public String upload(@RequestParam("file") MultipartFile file) {
    if (file.isEmpty()) {
        return "上传文件不能为空";
    }
    String fileName = file.getOriginalFilename();
    String filePath = "D:\\upload\\";
    File dest = new File(filePath + fileName);
    try {
        file.transferTo(dest);
        return "文件上传成功";
    } catch (IOException e) {
        e.printStackTrace();
    }
    return "文件上传失败";
}

2. 实现文件下载

（1）在页面中添加下载链接

<a href="download?fileName=xxx.txt">下载文件</a>

（2）在Controller中处理下载请求

@RequestMapping("/download")
public void download(HttpServletResponse response, @RequestParam("fileName") String fileName) throws IOException {
    String filePath = "D:\\upload\\";
    File file = new File(filePath + fileName);
    if (file.exists()) {
        response.setContentType("application/force-download");
        response.addHeader("Content-Disposition", "attachment;fileName=" + fileName);
        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("文件下载成功");
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (bis != null) {
                bis.close();
            }
            if (fis != null) {
                fis.close();
            }
        }
    }
}

以上就是使用SSM框架与layui实现文件上传与下载的全部内容。