Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.commons.validator; import org.apache.commons.validator.routines.InetAddressValidator; import java.util.regex.Matcher; import java.util.regex.Pattern; /** * <p>Perform email validations.</p> * <p> * This class is a Singleton; you can retrieve the instance via the getInstance() method. * </p> * <p> * Based on a script by <a href="mailto:stamhankar@hotmail.com">Sandeep V. Tamhankar</a> * http://javascript.internet.com * </p> * <p> * This implementation is not guaranteed to catch all possible errors in an email address. * For example, an address like nobody@noplace.somedog will pass validator, even though there * is no TLD "somedog" * </p>. * * @version $Revision: 1739358 $ * @since Validator 1.1 * @deprecated Use the new EmailValidator in the routines package. This class * will be removed in a future release. */ @Deprecated public class EmailValidator { private static final String SPECIAL_CHARS = "\\p{Cntrl}\\(\\)<>@,;:'\\\\\\\"\\.\\[\\]"; private static final String VALID_CHARS = "[^\\s" + SPECIAL_CHARS + "]"; private static final String QUOTED_USER = "(\"[^\"]*\")"; private static final String ATOM = VALID_CHARS + '+'; private static final String WORD = "((" + VALID_CHARS + "|')+|" + QUOTED_USER + ")"; // NOT USED private static final Pattern LEGAL_ASCII_PATTERN = Pattern.compile("^\\p{ASCII}+$"); // NOT USED private static final Pattern EMAIL_PATTERN = Pattern.compile("^(.+)@(.+)$"); private static final Pattern IP_DOMAIN_PATTERN = Pattern.compile("^\\[(.*)\\]$"); private static final Pattern TLD_PATTERN = Pattern.compile("^([a-zA-Z]+)$"); private static final Pattern USER_PATTERN = Pattern.compile("^\\s*" + WORD + "(\\." + WORD + ")*$"); private static final Pattern DOMAIN_PATTERN = Pattern.compile("^" + ATOM + "(\\." + ATOM + ")*\\s*$"); private static final Pattern ATOM_PATTERN = Pattern.compile("(" + ATOM + ")"); /** * Singleton instance of this class. */ private static final EmailValidator EMAIL_VALIDATOR = new EmailValidator(); /** * Returns the Singleton instance of this validator. * @return singleton instance of this validator. */ public static EmailValidator getInstance() { return EMAIL_VALIDATOR; } /** * Protected constructor for subclasses to use. */ protected EmailValidator() { super(); } /** * <p>Checks if a field has a valid e-mail address.</p> * * @param email The value validation is being performed on. A <code>null</code> * value is considered invalid. * @return true if the email address is valid. */ public boolean isValid(String email) { return org.apache.commons.validator.routines.EmailValidator.getInstance().isValid(email); } /** * Returns true if the domain component of an email address is valid. * @param domain being validated. * @return true if the email address's domain is valid. */ protected boolean isValidDomain(String domain) { boolean symbolic = false; // see if domain is an IP address in brackets Matcher ipDomainMatcher = IP_DOMAIN_PATTERN.matcher(domain); if (ipDomainMatcher.matches()) { InetAddressValidator inetAddressValidator = InetAddressValidator.getInstance(); if (inetAddressValidator.isValid(ipDomainMatcher.group(1))) { return true; } } else { // Domain is symbolic name symbolic = DOMAIN_PATTERN.matcher(domain).matches(); } if (symbolic) { if (!isValidSymbolicDomain(domain)) { return false; } } else { return false; } return true; } /** * Returns true if the user component of an email address is valid. * @param user being validated * @return true if the user name is valid. */ protected boolean isValidUser(String user) { return USER_PATTERN.matcher(user).matches(); } /** * Validates an IP address. Returns true if valid. * @param ipAddress IP address * @return true if the ip address is valid. */ protected boolean isValidIpAddress(String ipAddress) { Matcher ipAddressMatcher = IP_DOMAIN_PATTERN.matcher(ipAddress); for (int i = 1; i <= 4; i++) { // CHECKSTYLE IGNORE MagicNumber String ipSegment = ipAddressMatcher.group(i); if (ipSegment == null || ipSegment.length() <= 0) { return false; } int iIpSegment = 0; try { iIpSegment = Integer.parseInt(ipSegment); } catch (NumberFormatException e) { return false; } if (iIpSegment > 255) { // CHECKSTYLE IGNORE MagicNumber return false; } } return true; } /** * Validates a symbolic domain name. Returns true if it's valid. * @param domain symbolic domain name * @return true if the symbolic domain name is valid. */ protected boolean isValidSymbolicDomain(String domain) { String[] domainSegment = new String[10]; // CHECKSTYLE IGNORE MagicNumber boolean match = true; int i = 0; Matcher atomMatcher = ATOM_PATTERN.matcher(domain); while (match) { match = atomMatcher.matches(); if (match) { domainSegment[i] = atomMatcher.group(1); int l = domainSegment[i].length() + 1; domain = (l >= domain.length()) ? "" : domain.substring(l); i++; } } int len = i; // Make sure there's a host name preceding the domain. if (len < 2) { return false; } // TODO: the tld should be checked against some sort of configurable // list String tld = domainSegment[len - 1]; if (tld.length() > 1) { if (!TLD_PATTERN.matcher(tld).matches()) { return false; } } else { return false; } return true; } /** * Recursively remove comments, and replace with a single space. The simpler * regexps in the Email Addressing FAQ are imperfect - they will miss escaped * chars in atoms, for example. * Derived From Mail::RFC822::Address * @param emailStr The email address * @return address with comments removed. */ protected String stripComments(String emailStr) { String result = emailStr; String commentPat = "^((?:[^\"\\\\]|\\\\.)*(?:\"(?:[^\"\\\\]|\\\\.)*\"(?:[^\"\\\\]|\111111\\\\.)*)*)\\((?:[^()\\\\]|\\\\.)*\\)/"; Pattern commentMatcher = Pattern.compile(commentPat); while (commentMatcher.matcher(result).matches()) { result = result.replaceFirst(commentPat, "\1 "); } return result; } }