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1
55 package org.lateralnz.common.util;
56
57 import java.util.StringTokenizer  ;
58
59
65 public final class EmailUtils implements Constants {
66 private static final String INVALID_CHARS = " <>()[]\\,;:\"@ ";
67
68 private EmailUtils() {
69 }
70
71
76 public static final boolean isValidEmail(String email) {
77 int pos = email.indexOf('@');
78 if (pos <= 0 || pos == email.length()-1) {
79 return false;
80 }
81 else {
82 String localpart = email.substring(0,pos);
83 String domain = email.substring(pos+1);
84
85 if (!isValidLocalPart(localpart)) {
86 return false;
87 }
88 else {
89 return isValidDomain(domain);
90 }
91 }
92 }
93
94 private static final boolean isValidLocalPart(String localpart) {
95 if (localpart == null || localpart.length() < 1) {
96 return false;
97 }
98 else {
99 if (localpart.startsWith(DOT) || localpart.endsWith(DOT)) {
100 return false;
101 }
102 else {
103 StringTokenizer st = new StringTokenizer (localpart, DOT);
104 while (st.hasMoreTokens()) {
105 if (!isValidString(st.nextToken())) {
106 return false;
107 }
108 }
109 return true;
110 }
111 }
112 }
113
114 private static final boolean isValidDomain(String domain) {
115 if (domain.startsWith(DOT) || domain.endsWith(DOT)) {
116 return false;
117 }
118 else {
119 StringTokenizer st = new StringTokenizer (domain,DOT);
120 while (st.hasMoreTokens()) {
121 String token = st.nextToken();
122 if (token.startsWith(SQ_LEFT_BRACKET)) {
124 while (!token.endsWith(SQ_RIGHT_BRACKET) && st.hasMoreTokens()) {
125 token += DOT + st.nextToken();
126 }
127
128 if (!isValidDotNum(token)) {
129 return false;
130 }
131 }
132 else if (!isValidName(token) && !isValidNumber(token)) {
133 return false;
134 }
135 }
136
137 return true;
138 }
139 }
140
141 private static final boolean isValidName(String name) {
142 int len = name.length();
143 if (len == 0) {
144 return false;
145 }
146
147 char start = name.charAt(0);
148 char end = name.charAt(len-1);
149
150 if (!isValidAlpha(start)) {
151 return false;
152 }
153 else if (!isValidAlpha(end) && !isValidDigit(end)) {
154 return false;
155 }
156 else {
157 for (int i = 1; i < name.length()-1; i++) {
158 char c = name.charAt(i);
159 if (!isValidAlpha(c) && !isValidDigit(c) && c != '-') {
160 return false;
161 }
162 }
163 }
164 return true;
165 }
166
167 private static final boolean isValidNumber(String number) {
168 int len = number.length();
169 if (!number.startsWith(HASH) || len <= 1) {
170 return false;
171 }
172 else {
173 for (int i = 1; i < len; i++) {
174 if (!isValidDigit(number.charAt(i))) {
175 return false;
176 }
177 }
178 return true;
179 }
180 }
181
182 private static final boolean isValidDotNum(String dotnum) {
183 int len = dotnum.length();
184
185 if (len <= 2 || dotnum.charAt(0) != '[' || dotnum.charAt(len-1) != ']') {
186 return false;
187 }
188 else {
189 StringTokenizer st = new StringTokenizer (dotnum, DOT);
190
191 while (st.hasMoreTokens()) {
192 String s = st.nextToken();
193
194 if (s.length() > 3) {
195 return false;
196 }
197 else {
198 for (int i = 0; i < s.length(); i++) {
199 if (!isValidDigit(s.charAt(i))) {
200 return false;
201 }
202 }
203 }
204 }
205 return true;
206 }
207 }
208
209 private static final boolean isValidString(String s) {
210 for (int i = 0; i < s.length(); i++) {
211 char c = s.charAt(i);
212 if (c == '\\') {
213 i++;
214 c = s.charAt(i);
215 if (c < 0 || c > 127) {
216 return false;
217 }
218 }
219 else {
220 if (c < 32 || c > 126 || INVALID_CHARS.indexOf(c) >= 0) {
221 return false;
222 }
223 }
224 }
225 return true;
226 }
227
228 private static final boolean isValidAlpha(char c) {
229 return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
230 }
231
232 private static final boolean isValidDigit(char c) {
233 return (c >= '0' && c <= '9');
234 }
235
236
237 } |
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