后端：网络流

/**
     * 根据Request请求获取输入流，输入流的对于sensor和gateway的作用是一致的
     * 
     * @param request
     * @return
     */
    public static String getStringFromHttpRequest(HttpServletRequest request) {
        StringBuilder sb = new StringBuilder();
        try {
            InputStream is = request.getInputStream();
            byte[] buffer = new byte[1024];
            int len = 0;
            while ((len = is.read(buffer)) != -1) {
                String temp = new String(buffer, 0, len, "utf-8");
                sb.append(temp);
            }
            is.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        System.out.println(sb.toString());
        return sb.toString();
    }