Writing data to multiple Google Cloud Storage buckets
<p>I am writing a service which shall write data to different Google Cloud Storage account. The owner's of the accounts shall "sign up" with my service and I will be periodically writing data to their account's bucket.</p>

<p>I want to make the "signup" as easy as possible. I am still trying to wrap my head around google's OAuth2. 
I want to ideally create my own account to which the owner can give permission to buckets and I can write to their bucket. How do i achieve that ? 
I want to write data programmatically in JAVA</p>