/**
* begin crawling with a specific url use depth first search
*
* @throws IOException
* @throws SQLException
*/
public void crawl(String starturl) throws IOException, SQLException {
if (urlid >= MAXURL) // base case
return;
Document doc;
try {
doc = Jsoup.connect(starturl).get();
} catch (IOException e) {
// if the url is not valid, stop the crawling process
return;
} catch (IllegalArgumentException e) {
System.out.println("Must supply a valid URL : " + starturl);
return;
}
if (!urlList.contains(starturl)) {
urlList.add(starturl);
}
// if the url has already been crawled
else if (urlList.contains(starturl)) {
return;
}
Elements hrefs = doc.select("a");
urlid += 1;
// terminate the process if there is no more link in a webpage
if (hrefs == null || hrefs.size() == 0) return;
HashMap<String, Integer> wordMap = parseHTML(getHTMLContent(starturl));
insertDBWord(starturl, wordMap, urlid);
insertDBDescription(starturl, topOneHundred(starturl), urlid);
for (Element e : hrefs) {
String href = e.attr("href");
crawl(href); // depth first search;
}
}
/**
* begin crawling with a specific url use breadth first search
*
* @param starturl
* @throws IOException
* @throws SQLException
*/
public void bfscrawl(String starturl) throws IOException, SQLException {
if (starturl == null) {
return;
}
webqueue.add(starturl);
while (!webqueue.isEmpty() && urlid < MAXURL) {
String url = webqueue.poll();
Document doc;
Elements hrefs;
try {
doc = Jsoup.connect(url).get();
hrefs = doc.select("a");
// if (!urlList.contains(url)) {
if (!db.urlInDB(url)) {
String description = topOneHundred(url);
if (!db.descriptionInDB(description)) {
// urlList.add(url);
System.out.println(urlid);
urlid += 1;
HashMap<String, Integer> wordMap = parseHTML(getHTMLContent(url));
insertDBWord(url, wordMap, urlid);
insertDBDescription(url, description, urlid);
for (Element e : hrefs) {
String href = e.attr("href");
webqueue.add(href);
}
}
}
} catch (IOException e) {
// if the url is not valid, stop the crawling process
System.out.println("IOException : " + url);
continue;
} catch (IllegalArgumentException e) {
System.out.println(e + " Must supply a valid URL : " + url);
continue;
}
}
}
