Java tutorial
/* * Copyright (c) 2008-2011, Martijn Brinkers, Djigzo. * * This file is part of Djigzo email encryption. * * Djigzo is free software: you can redistribute it and/or modify * it under the terms of the GNU Affero General Public License * version 3, 19 November 2007 as published by the Free Software * Foundation. * * Djigzo 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 Affero General Public License for more details. * * You should have received a copy of the GNU Affero General Public * License along with Djigzo. If not, see <http://www.gnu.org/licenses/> * * Additional permission under GNU AGPL version 3 section 7 * * If you modify this Program, or any covered work, by linking or * combining it with aspectjrt.jar, aspectjweaver.jar, tyrex-1.0.3.jar, * freemarker.jar, dom4j.jar, mx4j-jmx.jar, mx4j-tools.jar, * spice-classman-1.0.jar, spice-loggerstore-0.5.jar, spice-salt-0.8.jar, * spice-xmlpolicy-1.0.jar, saaj-api-1.3.jar, saaj-impl-1.3.jar, * wsdl4j-1.6.1.jar (or modified versions of these libraries), * containing parts covered by the terms of Eclipse Public License, * tyrex license, freemarker license, dom4j license, mx4j license, * Spice Software License, Common Development and Distribution License * (CDDL), Common Public License (CPL) the licensors of this Program grant * you additional permission to convey the resulting work. */ package mitm.common.util; import java.util.regex.Matcher; import java.util.regex.Pattern; import org.apache.commons.lang.StringUtils; /** * Domain related helper functions like validating domain names etc. * * @author Martijn Brinkers * */ public class DomainUtils { public enum DomainType { FULLY_QUALIFIED, WILD_CARD, FRAGMENT }; /* * Regular expression pattern for a fully qualified domain with wild card. */ private final static Pattern wildcardPattern = Pattern .compile("^\\s*(([a-zA-Z0-9-]+|[\\*])\\.([a-zA-Z0-9-]+\\.)*([a-zA-Z0-9-]+)+)\\s*$"); /* * Regular expression pattern for a fully qualified domain. */ private final static Pattern fullyQualifiedPattern = Pattern .compile("^\\s*([a-zA-Z0-9-]+\\.([a-zA-Z0-9-]+\\.)*([a-zA-Z0-9-]+)+)\\s*$"); /* * Regular expression pattern for a fully or partly qualified domain. */ private final static Pattern fragmentPattern = Pattern.compile("^\\s*([a-zA-Z0-9-.]+)\\s*$"); /** * Checks if the domain is valid for the domain type. If not valid null will be returned * if valid, leading white space will be removed. */ public static String validate(String domain, DomainType domainType) { if (domain == null) { return null; } Pattern pattern = null; switch (domainType) { case FULLY_QUALIFIED: pattern = fullyQualifiedPattern; break; case WILD_CARD: pattern = wildcardPattern; break; case FRAGMENT: pattern = fragmentPattern; break; default: throw new IllegalArgumentException("Unknown domainType."); } Matcher matcher = pattern.matcher(domain); String validated = null; if (matcher.matches()) { validated = matcher.group(1); String trimmed = StringUtils.trim(validated); /* * A domain should not start or end with - */ if (StringUtils.startsWith(trimmed, "-") || StringUtils.endsWith(trimmed, "-")) { validated = null; } } return validated; } /** * Checks if the domain is valid for the domain type. If not valid null will be returned * if valid leading white space will be removed and the domain will be all lowercase. */ public static String canonicalizeAndValidate(String domain, DomainType domainType) { String validated = validate(domain, domainType); if (validated != null) { validated = validated.toLowerCase(); } return validated; } /** * Returns true if the domain is a wildcard domain (example: *.example.com) */ public static boolean isWildcardDomain(String domain) { String validated = canonicalizeAndValidate(domain, DomainType.WILD_CARD); return validated != null && validated.startsWith("*."); } /** * Removes the wildcard part of a domain. If domain does not have a wildcard part the complete domain * is returned. The returned domain is canonicalized. */ public static String removeWildcard(String domain) { String validated = canonicalizeAndValidate(domain, DomainType.WILD_CARD); return StringUtils.removeStart(validated, "*."); } /** * Return true if the domain is matched by the wildcard domain * * Examples: * - example.com is matched by *.example.com * - test.example.com is matched by *.example.com * - test.test.example.com is NOT matched by *.example.com */ public static boolean isWildcardMatchDomain(String domain, String wildcardDomain) { if (domain == null || wildcardDomain == null) { return false; } if (!isWildcardDomain(wildcardDomain)) { return false; } String validDomain = canonicalizeAndValidate(domain, DomainType.FULLY_QUALIFIED); if (validDomain == null) { return false; } String noWildcard = removeWildcard(wildcardDomain); if (StringUtils.equalsIgnoreCase(validDomain, noWildcard)) { return true; } /* * Check if we have a match when we remove the first part of the domain */ return StringUtils.equalsIgnoreCase(getUpperLevelDomain(validDomain), noWildcard); } /** * Returns the upper level domain. * * Example: sub.example.com returns example.com */ public static String getUpperLevelDomain(String domain) { return StringUtils.substringAfter(StringUtils.trimToEmpty(domain), "."); } }