So, I have an app (facebook app entity), and I have a page. I want to post to the page using the app, through the java code (by restfb, or any other suggestion). Looks like I am missing the phase where the page gives permission to the app to post. No idea how to do it. Thank you all. Uri.
You can only post "as Page", not "as App". You need a Page Access Token and you need to use the /page-id/feed endpoint to post. Links with information and example code:
来源：https://stackoverflow.com/questions/26219104/how-to-post-to-page-as-an-app