// This version of the crawler only+ −
// checks links in the "domain" urbanc+ −
+ −
import io.Source+ −
import scala.util.matching.Regex+ −
import scala.util._+ −
+ −
// gets the first 10K of a web-page+ −
def get_page(url: String) : String = {+ −
Try(Source.fromURL(url).take(10000).mkString) getOrElse + −
{ println(s" Problem with: $url"); ""}+ −
}+ −
+ −
// regexes for URLs and "my" domain+ −
val http_pattern = """"https?://[^"]*"""".r+ −
val my_urls = """urbanc""".r+ −
+ −
def unquote(s: String) = s.drop(1).dropRight(1)+ −
+ −
def get_all_URLs(page: String) : Set[String] = + −
http_pattern.findAllIn(page).map(unquote).toSet+ −
+ −
def crawl(url: String, n: Int) : Unit = {+ −
if (n == 0) ()+ −
else if (my_urls.findFirstIn(url) == None) { + −
println(s"Visiting: $n $url")+ −
get_page(url); () + −
}+ −
else {+ −
println(s"Visiting: $n $url")+ −
for (u <- get_all_URLs(get_page(url))) crawl(u, n - 1)+ −
}+ −
}+ −
+ −
// starting URL for the crawler+ −
//val startURL = """http://www.inf.kcl.ac.uk/staff/urbanc"""+ −
val startURL = """http://www.inf.kcl.ac.uk/staff/urbanc/msc-projects-14.html"""+ −
+ −
// can now deal with depth 3 and beyond+ −
crawl(startURL, 2)+ −
+ −
+ −