Check HTML links to local pages, using JSoup

CheckLink.java

import java.io.File;
import java.io.FileFilter;
import java.io.FilenameFilter;

import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.nodes.Element;
import org.jsoup.select.Elements;

import com.google.common.base.Charsets;
import com.google.common.io.Files;

/**
 * Check HTML links to local pages, using JSoup.
 */
public class CheckLink {

  private static final FileFilter DIRECTORY_FILEFILTER = new FileFilter() {
    @Override
    public boolean accept(File f) {
      return f.isDirectory();
    }
  };

  private static final FilenameFilter HTML_FILENAMEFILTER = new FilenameFilter() {
    @Override
    public boolean accept(File dir, String name) {
      return name.endsWith(".html");
    }
  };

  public static void main(String[] args) throws Exception {
    File root = new File("C:/Users/jbr/git/n4js");
    handleFolder(root);
  }

  /**
   * @param f
   * @throws Exception
   */
  private static void checkLinks(File file) throws Exception {
    String html = Files.toString(file, Charsets.UTF_8);
    Document doc = Jsoup.parse(html);

    Elements aElements = doc.getElementsByTag("a");
    for (Element e : aElements) {
      String href = e.attr("href");
      if (shouldFixLink(href)) {
        if (!href.startsWith("#")) {
          int i = href.lastIndexOf("#");
          String path;
          if (i > 0) {
            path = href.substring(0, i);
          }
          else {
            path = href;
          }
          File otherFile = new File(file.getParentFile(), path);
          if (!otherFile.exists()) {
            System.out.println("In file " + file.getAbsolutePath() + " there is a link to '" + href + "' that can not be found");
          }
        }
      }
    }
    System.out.println("Checked " + file.getAbsolutePath() + ".");

  }

  static boolean shouldFixLink(String href) {
    return href != null && !href.isEmpty() && !href.matches("(mailto\\:|[a-zA-Z]+\\://|//).+");
  }

  /**
   * @param root
   * @throws Exception
   */
  private static void handleFolder(File folder) throws Exception {
    File[] files = folder.listFiles(HTML_FILENAMEFILTER);
    for (File f : files) {
      checkLinks(f);
    }

    File[] folders = folder.listFiles(DIRECTORY_FILEFILTER);
    if (folders != null) {
      for (File f : folders) {
        handleFolder(f);
      }
    }
  }
}