I've been reading lots of documentation about Google API access and OAuth flow using it but I don't seem to get it working in my mind, so I want to get some help first in order to have a clear idea about how it works then I can code it using the corresponding API.
What I want to achieve is feed a Java application running in a PC with specific Google user data, like localization through Google Latitude API. In order to get this, OAuth must be used, so I need getting the user consent, then access the user data from the application running in my computer, and I don't know how to manage this.
I've already registered my application with the Google APIs Console and enabled the Google Latitude module. I've also tried the Latitude console application here and it works properly (a browser tab opened asking for a Google user; I entered it and I got the location data), but I'm having problems when trying to adapt the program flow to my needs.
In my application, the 'remote' user is supposed to send a request (a custom JSON message) to the server asking for service enable/disable, like allowing the server to track his/her position through Latitude. Then, AFAIK, the server should send to the user a URL so the user can give the consent, but I don't know how to get this URL and how the server realizes about this consent and gets the token (automatically? Google tracks this authorization process?). Once my server gets the specific user token, then I should be ready to get service data for that user using the received token.
As I said before, I've tried according to different references, but as the documentation seems to be really scattered and much of it is already deprecated, I've been unable to get it working.