code: private static String getIpInfoByIp(String url) throws IOException {
          OkHttpClient okHttpClient = new OkHttpClient();
          Request request = new Request.Builder()
                  .url(url)
                  .get()
                  .removeHeader(USER_AGENT_KEY)
                  .addHeader(USER_AGENT_KEY, USER_AGENT_VALUE)
                  .build();
          Call call = okHttpClient.newCall(request);
          Response response = call.execute();
          return response.body() == null ? "" : response.body().string();
      }
docs: 通过IP获取IP信息
  @param url url
  @return 服务器响应字符串
  @throws IOException IO异常