I've asked developer who designed the script about the situation. Apparently, it's not a bug, but a possible enhancement for future releases. There is an old [enhancement proposal](https://github.com/GluuFederation/oxAuth/issues/9) on github, but no estimations on how soon it will be delivered can be given atm, it's not perceived as a critical feature (unless one of our customers will need it)
He also shared a quick assessment of the current `gplus` script's code and his suggestions on how you could rewrite it to achieve what you need:
Next code snippet will create executor which is aware of web proxy:
org.apache.commons.httpclient.HttpClient httpClient = new HttpClient();
ClientExecutor executor = new ApacheHttpClientExecutor(httpClient);
Then, before line like this:
tokenResponse = tokenClient.exec()
That should be it. Then you need to apply the same approach to all other lines sending requests to Google's servers (or any other external hosts)
Please note that it's not a solid solution, and is not proven to work (though, all Gluu's sources are open, and you are free to study them in case any further difficulties will be encountered).
Unfortunately, we can't provide support on such non-standard issues for free. If you can be interested in buying a support contract, we could discuss possible ways to meet your needs.