Please refer the following steps:
1. I have logged in to facebook using my android app with "Facebook Login Button" as described at "https://developers.facebook.com/docs/android/login-with-facebook/v2.0".
2. Following facebook read permissions are granted to my app successfuly during this login.
"authButton.setReadPermissions(Arrays.asList("email", "read_friendlists", "friends_birthday", "friends_location"));"
3. socialService.getFacebookProfile(accessToken) -- returns correctly with profile details
4. socialService.linkUserFacebookAccount(currentUserName, accessToken, appID, secret) or
socialService.linkUserFacebookAccount(currentUserName, accessToken) -- returns success
5. socialService.getFacebookFriendsFromLinkUser(userName) or socialService.getFacebookFriendsFromAccessToken(accessToken) returns empty friend list. No exception/error is thrown..!!!!