服务器端接入华为推送遇到的connection reset问题

@Controller
@RequestMapping(value = "push")
public class PushCtrl {
    private Logger logger = LoggerFactory.getLogger(this.getClass());
    private static String apiUrl = "https://api.push.hicloud.com/pushsend.do"; // 应用级消息下发API
    @ResponseBody
    @RequestMapping(value = "doTransfer",method=RequestMethod.POST)
    public void doTransfer(HttpServletRequest request,HttpServletResponse httpServletResponse)
            throws Exception {
        byte[] data = FileCopyUtils.copyToByteArray(request.getInputStream());
        String jsonData = new String(data, "UTF-8");
        JSONObject jo = JSONObject.fromObject(new String(request.getParameter("nsp_ctx")));
        String appId = (String)jo.get("appId");
        String postUrl = apiUrl + "?nsp_ctx=" + URLEncoder.encode("{\"ver\":\"1\", \"appId\":\"" + appId + "\"}", "UTF-8");
        String response = httpPost(postUrl, jsonData, 50000, 50000);
        httpServletResponse.setContentType("text/plain;charset=utf-8");
        PrintWriter responseStream = httpServletResponse.getWriter();
        responseStream.println(response);
        responseStream.close();
    }

    @ResponseBody
    @RequestMapping(value = "test",method=RequestMethod.GET)
    public ModelMap test(ModelMap m) {
        m.put("key", "value");
        return m;
    }
    
    public String httpPost(String httpUrl, String data, int connectTimeout,
            int readTimeout) throws Exception {
        OutputStream outPut = null;
        HttpURLConnection urlConnection = null;
        InputStream in = null;

        try {
            URL url = new URL(httpUrl);
            urlConnection = (HttpURLConnection) url.openConnection();
            urlConnection.setRequestMethod("POST");
            urlConnection.setDoOutput(true);
            urlConnection.setDoInput(true);
            urlConnection.setRequestProperty("Content-Type",
                    "application/x-www-form-urlencoded; charset=UTF-8");
            urlConnection.setConnectTimeout(connectTimeout);
            urlConnection.setReadTimeout(readTimeout);
            urlConnection.connect();

            // POST data
            outPut = urlConnection.getOutputStream();
            outPut.write(data.getBytes("UTF-8"));
            outPut.flush();

            // read response
            if (urlConnection.getResponseCode() < 400) {
                in = urlConnection.getInputStream();
            } else {
                in = urlConnection.getErrorStream();
            }

            List<String> lines = IOUtils.readLines(in,
                    urlConnection.getContentEncoding());
            StringBuffer strBuf = new StringBuffer();
            for (String line : lines) {
                strBuf.append(line);
            }
            logger.info(strBuf.toString());
            return strBuf.toString();
        } finally {
            IOUtils.closeQuietly(outPut);
            IOUtils.closeQuietly(in);
            if (urlConnection != null) {
                urlConnection.disconnect();
            }
        }
    }
}