Domains.java

/*
 * GNU LESSER GENERAL PUBLIC LICENSE Copyright (C) 2006 The Lobo Project
 * 
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 * 
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 * 
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 * 
 * Contact info: lobochief@users.sourceforge.net
 */
/*
 * Created on Jun 2, 2005
 */
package com.nvarghese.beowulf.common.cobra.util;

import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;

/**
 * @author J. H. S.
 */
public class Domains {

	private static final Collection gTLDs;

	static {
		gTLDs = new HashSet();
		gTLDs.add(".com");
		gTLDs.add(".edu");
		gTLDs.add(".gov");
		gTLDs.add(".int");
		gTLDs.add(".mil");
		gTLDs.add(".net");
		gTLDs.add(".org");
		gTLDs.add(".biz");
		gTLDs.add(".info");
		gTLDs.add(".name");
		gTLDs.add(".pro");
		gTLDs.add(".aero");
		gTLDs.add(".coop");
		gTLDs.add(".museum");
		// TODO: New gTLDs?
	}

	/**
	 * 
	 */
	private Domains() {

		super();
	}

	public static boolean isValidCookieDomain(String domain, String hostName) {

		String plainDomain;
		if (!domain.startsWith(".")) {
			// Valid domains must start with a dot
			// according to RFC 2109, but
			// RFC 2965 specifies a dot is prepended
			// in the Set-Cookie2 header.
			plainDomain = domain;
			domain = "." + domain;
		} else {
			plainDomain = domain.substring(1);
		}
		String plainDomainTL = plainDomain.toLowerCase();
		String hostNameTL = hostName.toLowerCase();
		if (!hostNameTL.endsWith(plainDomainTL)) {
			return false;
		}
		int lastDotIdx = domain.lastIndexOf('.');
		if (lastDotIdx == -1) {
			return false;
		}
		String suffix = domain.substring(lastDotIdx).toLowerCase();
		if (gTLDs.contains(suffix)) {
			return Strings.countChars(domain, '.') >= 2;
		} else {
			return Strings.countChars(domain, '.') >= 3;
		}
	}

	/**
	 * 
	 * @param host
	 *            A host name in lower case.
	 * @return
	 */
	public static boolean endsWithGTLD(String host) {

		Iterator i = gTLDs.iterator();
		while (i.hasNext()) {
			String ending = (String) i.next();
			if (host.endsWith(ending)) {
				return true;
			}
		}
		return false;
	}

	public static boolean isLikelyHostName(String name) {

		String nameTL = name.toLowerCase();
		if (nameTL.startsWith("www.")) {
			return true;
		}
		if (endsWithGTLD(name)) {
			return true;
		}
		int lastDotIdx = nameTL.lastIndexOf('.');
		if (lastDotIdx == -1) {
			return false;
		}
		// Check for country code.
		return lastDotIdx == nameTL.length() - 3;
	}

	public static Collection getPossibleDomains(String hostName) {

		Collection domains = new LinkedList();
		domains.add(hostName);
		int dotIdx = hostName.indexOf('.', 1);
		if (dotIdx == -1) {
			return domains;
		}
		String testDomain = hostName.substring(dotIdx);
		if (!Domains.isValidCookieDomain(testDomain, hostName)) {
			return domains;
		}
		domains.addAll(Domains.getPossibleDomains(testDomain.substring(1)));
		return domains;
	}
}