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: xamjadmin@users.sourceforge.net
 */
/*
 * Created on Jun 2, 2005
 */
package org.cobra_grendel.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?
    }

    /**
     * 
     * @param host
     *            A host name in lower case.
     * @return
     */
    public static boolean endsWithGTLD(final String host)
    {
        Iterator i = gTLDs.iterator();
        while (i.hasNext())
        {
            String ending = (String) i.next();
            if (host.endsWith(ending))
            {
                return true;
            }
        }
        return false;
    }

    public static Collection getPossibleDomains(final 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;
    }

    public static boolean isLikelyHostName(final 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 boolean isValidCookieDomain(String domain, final 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;
        }
    }

    /**
	 * 
	 */
    private Domains()
    {
        super();
    }
}