public static void Crawl()
{
//Get initial links
if (links.Count == 0)
{
GetLinksFromSite(startLink);
}
for (int j = 0; j < links.Count; j++)
{
Link link = links[j];
if (!link.visited)
{
links[j].visited = true;
MongoConnection.UpdateDB(link.link);
GetLinksFromSite(link.link);
}
}
}
public static void GetLinksFromSite(string currentLink)
{
HtmlWeb html = new HtmlWeb();
HtmlDocument document;
Console.WriteLine(currentLink);
try
{
document = html.Load(currentLink);
}
catch
{
return;
}
HtmlNode page = document.DocumentNode;
List <string> linksOnSite = new List <string>();
foreach (HtmlNode item in page.QuerySelectorAll("a"))
{
if (item.GetAttributes("href").First() == null)
{
continue;
}
string url = item.GetAttributes("href").First().Value;
if (!url.StartsWith("https"))
{
continue;
}
//Remove URL fragment
int hashPos = url.IndexOf('#');
if (hashPos != -1)
{
url = url.Substring(0, hashPos);
}
//Check if link is already on same site
foreach (string link in linksOnSite)
{
if (link == url)
{
goto here;
}
}
//Check if link is already in list
foreach (Link link in links)
{
if (link.link == url)
{
goto here;
}
}
links.Add(new Link(url, currentLink));
linksOnSite.Add(url);
//Insert link into MongoDB
BsonDocument bson = new BsonDocument {
{ "url", url }, { "origin", currentLink }, { "visited", false }
};
MongoConnection.InsertToDB(bson);
here :;
}
}
static void Main(string[] args)
{
MongoConnection.ConnectToDB();
links = MongoConnection.ReadAllDB();
Crawl();
}