Java 通过url响应图片

@ApiOperation(value = "海报图片", httpMethod = "GET", response = Poster.class, notes = "query")
    @RequestMapping(path = "/posterImage", method = RequestMethod.GET)
    public void posterImage(@ApiParam("图片地址") @RequestParam String imgUrl, HttpServletResponse response) throws Exception {
        log.info(">>>> Method:history>>posterImage request:{}", imgUrl);

        try {
            //new一个URL对象
            URL url = new URL(imgUrl);
            //打开链接
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            //设置请求方式为"GET"
            conn.setRequestMethod("GET");
            //超时响应时间为5秒
            conn.setConnectTimeout(5 * 1000);
            //通过输入流获取图片数据
            InputStream inStream = conn.getInputStream();
            //得到图片的二进制数据，以二进制封装得到数据，具有通用性
            BufferedImage img = ImageIO.read(inStream);
            if (img != null) {
                String format = imgUrl.substring(imgUrl.lastIndexOf(".") + 1);
                ImageIO.write(img, format, response.getOutputStream());
            }
        } catch (IOException e) {
            e.printStackTrace();
        }

    }