In order to access the Google drive API or Google drive SDK you must first register your application on Google Developer console and enable the google drive API.
After that its a good idea to use one of the official google client libraries to access the API.
DocumentationSamplesGoogle API Client L...
As most of the information contained within Google drive is private user data. You must have an access token in order to access the information. Access tokens can be retrieved via the Oauth2 authentication process.
GET https://www.googleapis.com/drive/v2/files?access_token={Valid Access Token}
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