后台代码

/**
     * 在线浏览文件
     *
     * @param response 文件流
     * @throws Exception        流异常
     */
    @ApiModelProperty(value = "在线浏览文件")
    @GetMapping("downFile")
    public void downFile(HttpServletResponse response) throws Exception {
        String  filePath = "D:\\file\\1.jpg";
        response.setContentType(Files.probeContentType(Paths.get(fileInfo.getFilePath(filePath))));
        File file = new File(filePath);
        byte[] bytes = Files.toByteArray(file);
        out.write(bytes);
        out.close();
    }