001/* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017package org.apache.commons.validator.routines; 018 019import java.io.Serializable; 020import java.util.regex.Matcher; 021import java.util.regex.Pattern; 022 023/** 024 * <p>Perform email validations.</p> 025 * <p> 026 * Based on a script by <a href="mailto:stamhankar@hotmail.com">Sandeep V. Tamhankar</a> 027 * http://javascript.internet.com 028 * </p> 029 * <p> 030 * This implementation is not guaranteed to catch all possible errors in an email address. 031 * </p>. 032 * 033 * @since 1.4 034 */ 035public class EmailValidator implements Serializable { 036 037 private static final long serialVersionUID = 1705927040799295880L; 038 039 private static final String SPECIAL_CHARS = "\\p{Cntrl}\\(\\)<>@,;:'\\\\\\\"\\.\\[\\]"; 040 private static final String VALID_CHARS = "(\\\\.)|[^\\s" + SPECIAL_CHARS + "]"; 041 private static final String QUOTED_USER = "(\"(\\\\\"|[^\"])*\")"; 042 private static final String WORD = "((" + VALID_CHARS + "|')+|" + QUOTED_USER + ")"; 043 044 private static final String EMAIL_REGEX = "^(.+)@(\\S+)$"; 045 private static final String IP_DOMAIN_REGEX = "^\\[(.*)\\]$"; 046 private static final String USER_REGEX = "^" + WORD + "(\\." + WORD + ")*$"; 047 048 private static final Pattern EMAIL_PATTERN = Pattern.compile(EMAIL_REGEX); 049 private static final Pattern IP_DOMAIN_PATTERN = Pattern.compile(IP_DOMAIN_REGEX); 050 private static final Pattern USER_PATTERN = Pattern.compile(USER_REGEX); 051 052 private static final int MAX_USERNAME_LEN = 64; 053 054 /** 055 * Singleton instance of this class, which 056 * doesn't consider local addresses as valid. 057 */ 058 private static final EmailValidator EMAIL_VALIDATOR = new EmailValidator(false, false); 059 060 /** 061 * Singleton instance of this class, which 062 * doesn't consider local addresses as valid. 063 */ 064 private static final EmailValidator EMAIL_VALIDATOR_WITH_TLD = new EmailValidator(false, true); 065 066 /** 067 * Singleton instance of this class, which does 068 * consider local addresses valid. 069 */ 070 private static final EmailValidator EMAIL_VALIDATOR_WITH_LOCAL = new EmailValidator(true, false); 071 072 /** 073 * Singleton instance of this class, which does 074 * consider local addresses valid. 075 */ 076 private static final EmailValidator EMAIL_VALIDATOR_WITH_LOCAL_WITH_TLD = new EmailValidator(true, true); 077 078 /** 079 * Returns the Singleton instance of this validator. 080 * 081 * @return singleton instance of this validator. 082 */ 083 public static EmailValidator getInstance() { 084 return EMAIL_VALIDATOR; 085 } 086 087 /** 088 * Returns the Singleton instance of this validator, 089 * with local validation as required. 090 * 091 * @param allowLocal Should local addresses be considered valid? 092 * @return singleton instance of this validator 093 */ 094 public static EmailValidator getInstance(final boolean allowLocal) { 095 return getInstance(allowLocal, false); 096 } 097 098 /** 099 * Returns the Singleton instance of this validator, 100 * with local validation as required. 101 * 102 * @param allowLocal Should local addresses be considered valid? 103 * @param allowTld Should TLDs be allowed? 104 * @return singleton instance of this validator 105 */ 106 public static EmailValidator getInstance(final boolean allowLocal, final boolean allowTld) { 107 if (allowLocal) { 108 if (allowTld) { 109 return EMAIL_VALIDATOR_WITH_LOCAL_WITH_TLD; 110 } 111 return EMAIL_VALIDATOR_WITH_LOCAL; 112 } 113 if (allowTld) { 114 return EMAIL_VALIDATOR_WITH_TLD; 115 } 116 return EMAIL_VALIDATOR; 117 } 118 119 private final boolean allowTld; 120 121 private final DomainValidator domainValidator; 122 123 /** 124 * Protected constructor for subclasses to use. 125 * 126 * @param allowLocal Should local addresses be considered valid? 127 */ 128 protected EmailValidator(final boolean allowLocal) { 129 this(allowLocal, false); 130 } 131 132 /** 133 * Protected constructor for subclasses to use. 134 * 135 * @param allowLocal Should local addresses be considered valid? 136 * @param allowTld Should TLDs be allowed? 137 */ 138 protected EmailValidator(final boolean allowLocal, final boolean allowTld) { 139 this.allowTld = allowTld; 140 this.domainValidator = DomainValidator.getInstance(allowLocal); 141 } 142 143 /** 144 * constructor for creating instances with the specified domainValidator 145 * 146 * @param allowLocal Should local addresses be considered valid? 147 * @param allowTld Should TLDs be allowed? 148 * @param domainValidator allow override of the DomainValidator. 149 * The instance must have the same allowLocal setting. 150 * @since 1.7 151 */ 152 public EmailValidator(final boolean allowLocal, final boolean allowTld, final DomainValidator domainValidator) { 153 this.allowTld = allowTld; 154 if (domainValidator == null) { 155 throw new IllegalArgumentException("DomainValidator cannot be null"); 156 } 157 if (domainValidator.isAllowLocal() != allowLocal) { 158 throw new IllegalArgumentException("DomainValidator must agree with allowLocal setting"); 159 } 160 this.domainValidator = domainValidator; 161 } 162 163 /** 164 * <p>Checks if a field has a valid e-mail address.</p> 165 * 166 * @param email The value validation is being performed on. A <code>null</code> 167 * value is considered invalid. 168 * @return true if the email address is valid. 169 */ 170 public boolean isValid(final String email) { 171 if (email == null) { 172 return false; 173 } 174 175 if (email.endsWith(".")) { // check this first - it's cheap! 176 return false; 177 } 178 179 // Check the whole email address structure 180 final Matcher emailMatcher = EMAIL_PATTERN.matcher(email); 181 if (!emailMatcher.matches()) { 182 return false; 183 } 184 185 if (!isValidUser(emailMatcher.group(1))) { 186 return false; 187 } 188 189 if (!isValidDomain(emailMatcher.group(2))) { 190 return false; 191 } 192 193 return true; 194 } 195 196 /** 197 * Returns true if the domain component of an email address is valid. 198 * 199 * @param domain being validated, may be in IDN format 200 * @return true if the email address's domain is valid. 201 */ 202 protected boolean isValidDomain(final String domain) { 203 // see if domain is an IP address in brackets 204 final Matcher ipDomainMatcher = IP_DOMAIN_PATTERN.matcher(domain); 205 206 if (ipDomainMatcher.matches()) { 207 final InetAddressValidator inetAddressValidator = 208 InetAddressValidator.getInstance(); 209 return inetAddressValidator.isValid(ipDomainMatcher.group(1)); 210 } 211 // Domain is symbolic name 212 if (allowTld) { 213 return domainValidator.isValid(domain) || !domain.startsWith(".") && domainValidator.isValidTld(domain); 214 } 215 return domainValidator.isValid(domain); 216 } 217 218 /** 219 * Returns true if the user component of an email address is valid. 220 * 221 * @param user being validated 222 * @return true if the user name is valid. 223 */ 224 protected boolean isValidUser(final String user) { 225 226 if (user == null || user.length() > MAX_USERNAME_LEN) { 227 return false; 228 } 229 230 return USER_PATTERN.matcher(user).matches(); 231 } 232 233}