Groovy script that fetch all feeds with comments and 2nd level comments from a facebook page, using the library RestFB.

gistfile1.groovy

@Grapes(
    @Grab(group='com.restfb', module='restfb', version='1.6.12')
)

import com.restfb.DefaultFacebookClient
import com.restfb.Parameter
import com.restfb.types.*

def token = "FACEBOOK_AUTH_TOKEN"
def page_id = "PAGE_ID"

this.facebook = new DefaultFacebookClient(token)

def topicsInPage = facebook.fetchConnection("${page_id}/feed", Post.class, Parameter.with("since", "1389984915")); // this operation allows "since" parameter

println "==============PAGE (${page_id})======================"
topicsInPage.data.each { topic -> 
  if (topic.message) println "Topic -> Body[${topic.message}] created at ${topic.createdTime.time / 1000}" 
  findComments(topic.id, "  Comment ->")
}

def findComments(id, head) {
    def comments = facebook.fetchConnection("${id}/comments", Comment.class, Parameter.with("since", "1390313487")) // in this operation "since" its not working
    comments.data.each { comment -> 
        println "${head}Body[${comment.message}] created at ${comment.createdTime.time  / 1000}"
        findComments(comment.id, "    Response ->")
    }
}