@RequestMapping(value = "/tools/printContract")

public void cell(HttpServletResponse response,HttpServletRequest request,String outName) {

    //根据outName获取到保存在服务器上的文件

    String filePath = request.getSession().getServletContext().getRealPath(ImgUtil.TOOLS_PATH+ImgUtil.TOOLS_TXT)+'/'+outName+".txt";

    try(OutputStream out = response.getOutputStream()) {

        Date currentTime = new Date();

        SimpleDateFormat formatter = new SimpleDateFormat("yyyyMMdd_HHmmss");

        String dateString = formatter.format(currentTime);

        //fileName是输出的文件的名字（不支持中文），包括了后缀

        String fileName = "EncryptFile_" + dateString + ".txt";

        byte[] bytes = FileEcodeUtil.file2byte(filePath);

        response.setContentType("application/x-msdownload");

        response.setHeader("Content-Disposition","attachment;filename=" + fileName);

        response.setContentLength(bytes.length);

        out.write(bytes);

        out.flush();

    } catch (IOException e) {

    //e.printStackTrace();

    }

}

//上面用到的file2byte方法为：

public static byte[] file2byte(String filePath) {

    byte[] buffer = null;

    File file = new File(filePath);

    try (FileInputStream fis = new FileInputStream(file);

         ByteArrayOutputStream bos = new ByteArrayOutputStream()) {

        byte[] b = new byte[1024];

        int n;

        while ((n = fis.read(b)) != -1) {

            bos.write(b, 0, n);

        }

        buffer = bos.toByteArray();

    } catch (Exception e) {

        // e.printStackTrace();

    }

    return buffer;

}