传入url地址请求服务器api，浏览器显示图片

    @RequestMapping("/proxyImage")
    public void proxyImage(HttpServletRequest request, HttpServletResponse response){

        String urlImage = request.getParameter("urlImage");
        URL url;
        HttpURLConnection connection = null;
        DataInputStream in = null;
        OutputStream out = null;
        byte[] buff = new byte[1024];

        try {
            url = new URL(urlImage);
            connection = (HttpURLConnection)url.openConnection();
            in = new DataInputStream(connection.getInputStream());

            response.setContentType("image/png");

            out = response.getOutputStream();
            int len = 0;
            while ((len = in.read(buff)) != -1) {
                out.write(buff, 0, len);
            }
        } catch (MalformedURLException e1) {
            log.error(e1.getMessage());
        } catch (IOException e2) {
            log.error(e2.getMessage());
        } finally {
            try {
                in.close();
                out.close();
                response.flushBuffer();
            } catch (IOException e3) {
                log.error("关闭流失败" + e3.getMessage(), e3);
            }
            connection.disconnect();
        }
    }