public BackLinkNeighborhood[] getBacklinks(URL url) throws IOException {
        URL normalizedURL = new URL(url.getProtocol(), url.getHost(), "/");
        String urlId = url2id.get(normalizedURL.toString());
        if (urlId == null) {
            return null;
        }
        String strLinks = authGraph.get(urlId);
        if (strLinks == null) {
            return null;
        } else {
            List<BackLinkNeighborhood> tempBacklinks = new ArrayList<>();
            String[] backlinkIds = strLinks.split("###");
            for (String backlinkId : backlinkIds) {
                String url_title = hubID.get(backlinkId);
                if (url_title != null) {
                    BackLinkNeighborhood bln = new BackLinkNeighborhood();
                    String[] fields = url_title.split(":::");
                    bln.setLink(fields[0]);
                    if (fields.length > 1) {
                        bln.setTitle(fields[1]);
                    }
                    tempBacklinks.add(bln);
                }
            }
            BackLinkNeighborhood[] blns = new BackLinkNeighborhood[tempBacklinks.size()];
            tempBacklinks.toArray(blns);
            return blns;
        }
    }
This method retrieves the backlinks of a given url.
ache/src/main/java/achecrawler/link/BipartiteGraphRepository.java