facebook获取长期access token

Having found that it is possible to generate a Facebook Page Access Token that does not expire (with help from @Igy), here is a clear, step-by-step quide for all those looking to the same:

1. Make sure you are the admin of the FB page you wish to pull info from
2. Create a FB App (should be with the same user account that is the page admin)
3. Head over to the Facebook Graph API Explorer
4. On the top right, select the FB App you created from the "Application" drop down list
5. Click "Get Access Token"
6. Make sure you add the manage_pages permission
7. Convert this short-lived access token into a long-lived one by making this Graph API call: oauth/access_token?client_id=<your FB App ID >&client_secret=<your FB App secret>&grant_type=fb_exchange_token&fb_exchange_token=<your short-lived access token>
8. Grab the new long-lived access token returned back
9. Make a Graph API call to see your accounts using the new long-lived access token:https://graph.facebook.com/me/accounts?access_token=<your long-lived access token>
10. Grab the access_token for the page you'll be pulling info from
11. Lint the token to see that it is set toExpires: Never!

That should do it. You should now have a Facebook Page Access Token that doesn't expire!