I hope this will be helpful. There is only one way in the official FB SDK with Graph Api v2.1 (since fql is no longer available in 2.1) - for each message you must send a request to https://graph.facebook.com/v2.1/{post-id}/likes. You can also use .../{post-id}/likes?limit=XXX. In response, you will get an array of like this:
data": [
{
"id": "xxxxxxxx",
"name": "yyyyyy"
},
....
]
. - . - . .
- , . Facebook, . .