WxPayServiceImpl的post方法，编码转换存在BUG

    try {
      responseString = new String(response.bodyText().getBytes(CharEncoding.ISO_8859_1), CharEncoding.UTF_8);
    } catch (UnsupportedEncodingException e) {
      e.printStackTrace();
    }

服务器返回值的编码并非全是ISO_8859_1，建议更换为：EntityUtils.toString(response.getEntity(), Consts.UTF_8);