J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2004 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package com.sun.jndi.dns; |
| 27 | |
| 28 | |
| 29 | import java.util.ArrayList; |
| 30 | import java.util.Comparator; |
| 31 | import java.util.Enumeration; |
| 32 | import java.util.Iterator; |
| 33 | |
| 34 | import javax.naming.*; |
| 35 | |
| 36 | |
| 37 | /** |
| 38 | * <tt>DnsName</tt> implements compound names for DNS as specified by |
| 39 | * RFCs 1034 and 1035, and as updated and clarified by RFCs 1123 and 2181. |
| 40 | * |
| 41 | * <p> The labels in a domain name correspond to JNDI atomic names. |
| 42 | * Each label must be less than 64 octets in length, and only the |
| 43 | * optional root label at the end of the name may be 0 octets long. |
| 44 | * The sum of the lengths of all labels in a name, plus the number of |
| 45 | * non-root labels plus 1, must be less than 256. The textual |
| 46 | * representation of a domain name consists of the labels, escaped as |
| 47 | * needed, dot-separated, and ordered right-to-left. |
| 48 | * |
| 49 | * <p> A label consists of a sequence of octets, each of which may |
| 50 | * have any value from 0 to 255. |
| 51 | * |
| 52 | * <p> <em>Host names</em> are a subset of domain names. |
| 53 | * Their labels contain only ASCII letters, digits, and hyphens, and |
| 54 | * none may begin or end with a hyphen. While names not conforming to |
| 55 | * these rules may be valid domain names, they will not be usable by a |
| 56 | * number of DNS applications, and should in most cases be avoided. |
| 57 | * |
| 58 | * <p> DNS does not specify an encoding (such as UTF-8) to use for |
| 59 | * octets with non-ASCII values. As of this writing there is some |
| 60 | * work going on in this area, but it is not yet finalized. |
| 61 | * <tt>DnsName</tt> currently converts any non-ASCII octets into |
| 62 | * characters using ISO-LATIN-1 encoding, in effect taking the |
| 63 | * value of each octet and storing it directly into the low-order byte |
| 64 | * of a Java character and <i>vice versa</i>. As a consequence, no |
| 65 | * character in a DNS name will ever have a non-zero high-order byte. |
| 66 | * When the work on internationalizing domain names has stabilized |
| 67 | * (see for example <i>draft-ietf-idn-idna-10.txt</i>), <tt>DnsName</tt> |
| 68 | * may be updated to conform to that work. |
| 69 | * |
| 70 | * <p> Backslash (<tt>\</tt>) is used as the escape character in the |
| 71 | * textual representation of a domain name. The character sequence |
| 72 | * `<tt>\DDD</tt>', where <tt>DDD</tt> is a 3-digit decimal number |
| 73 | * (with leading zeros if needed), represents the octet whose value |
| 74 | * is <tt>DDD</tt>. The character sequence `<tt>\C</tt>', where |
| 75 | * <tt>C</tt> is a character other than <tt>'0'</tt> through |
| 76 | * <tt>'9'</tt>, represents the octet whose value is that of |
| 77 | * <tt>C</tt> (again using ISO-LATIN-1 encoding); this is particularly |
| 78 | * useful for escaping <tt>'.'</tt> or backslash itself. Backslash is |
| 79 | * otherwise not allowed in a domain name. Note that escape characters |
| 80 | * are interpreted when a name is parsed. So, for example, the character |
| 81 | * sequences `<tt>S</tt>', `<tt>\S</tt>', and `<tt>\083</tt>' each |
| 82 | * represent the same one-octet name. The <tt>toString()</tt> method |
| 83 | * does not generally insert escape sequences except where necessary. |
| 84 | * If, however, the <tt>DnsName</tt> was constructed using unneeded |
| 85 | * escapes, those escapes may appear in the <tt>toString</tt> result. |
| 86 | * |
| 87 | * <p> Atomic names passed as parameters to methods of |
| 88 | * <tt>DnsName</tt>, and those returned by them, are unescaped. So, |
| 89 | * for example, <tt>(new DnsName()).add("a.b")</tt> creates an |
| 90 | * object representing the one-label domain name <tt>a\.b</tt>, and |
| 91 | * calling <tt>get(0)</tt> on this object returns <tt>"a.b"</tt>. |
| 92 | * |
| 93 | * <p> While DNS names are case-preserving, comparisons between them |
| 94 | * are case-insensitive. When comparing names containing non-ASCII |
| 95 | * octets, <tt>DnsName</tt> uses case-insensitive comparison |
| 96 | * between pairs of ASCII values, and exact binary comparison |
| 97 | * otherwise. |
| 98 | |
| 99 | * <p> A <tt>DnsName</tt> instance is not synchronized against |
| 100 | * concurrent access by multiple threads. |
| 101 | * |
| 102 | * @author Scott Seligman |
| 103 | */ |
| 104 | |
| 105 | |
| 106 | public final class DnsName implements Name { |
| 107 | |
| 108 | // If non-null, the domain name represented by this DnsName. |
| 109 | private String domain = ""; |
| 110 | |
| 111 | // The labels of this domain name, as a list of strings. Index 0 |
| 112 | // corresponds to the leftmost (least significant) label: note that |
| 113 | // this is the reverse of the ordering used by the Name interface. |
| 114 | private ArrayList labels = new ArrayList(); |
| 115 | |
| 116 | // The number of octets needed to carry this domain name in a DNS |
| 117 | // packet. Equal to the sum of the lengths of each label, plus the |
| 118 | // number of non-root labels, plus 1. Must remain less than 256. |
| 119 | private short octets = 1; |
| 120 | |
| 121 | |
| 122 | /** |
| 123 | * Constructs a <tt>DnsName</tt> representing the empty domain name. |
| 124 | */ |
| 125 | public DnsName() { |
| 126 | } |
| 127 | |
| 128 | /** |
| 129 | * Constructs a <tt>DnsName</tt> representing a given domain name. |
| 130 | * |
| 131 | * @param name the domain name to parse |
| 132 | * @throws InvalidNameException if <tt>name</tt> does not conform |
| 133 | * to DNS syntax. |
| 134 | */ |
| 135 | public DnsName(String name) throws InvalidNameException { |
| 136 | parse(name); |
| 137 | } |
| 138 | |
| 139 | /* |
| 140 | * Returns a new DnsName with its name components initialized to |
| 141 | * the components of "n" in the range [beg,end). Indexing is as |
| 142 | * for the Name interface, with 0 being the most significant. |
| 143 | */ |
| 144 | private DnsName(DnsName n, int beg, int end) { |
| 145 | // Compute indexes into "labels", which has least-significant label |
| 146 | // at index 0 (opposite to the convention used for "beg" and "end"). |
| 147 | int b = n.size() - end; |
| 148 | int e = n.size() - beg; |
| 149 | labels.addAll(n.labels.subList(b, e)); |
| 150 | |
| 151 | if (size() == n.size()) { |
| 152 | domain = n.domain; |
| 153 | octets = n.octets; |
| 154 | } else { |
| 155 | Iterator iter = labels.iterator(); |
| 156 | while (iter.hasNext()) { |
| 157 | String label = (String) iter.next(); |
| 158 | if (label.length() > 0) { |
| 159 | octets += (short) (label.length() + 1); |
| 160 | } |
| 161 | } |
| 162 | } |
| 163 | } |
| 164 | |
| 165 | |
| 166 | public String toString() { |
| 167 | if (domain == null) { |
| 168 | StringBuffer buf = new StringBuffer(); |
| 169 | Iterator iter = labels.iterator(); |
| 170 | while (iter.hasNext()) { |
| 171 | String label = (String) iter.next(); |
| 172 | if (buf.length() > 0 || label.length() == 0) { |
| 173 | buf.append('.'); |
| 174 | } |
| 175 | escape(buf, label); |
| 176 | } |
| 177 | domain = buf.toString(); |
| 178 | } |
| 179 | return domain; |
| 180 | } |
| 181 | |
| 182 | /** |
| 183 | * Does this domain name follow <em>host name</em> syntax? |
| 184 | */ |
| 185 | public boolean isHostName() { |
| 186 | Iterator iter = labels.iterator(); |
| 187 | while (iter.hasNext()) { |
| 188 | if (!isHostNameLabel((String) iter.next())) { |
| 189 | return false; |
| 190 | } |
| 191 | } |
| 192 | return true; |
| 193 | } |
| 194 | |
| 195 | public short getOctets() { |
| 196 | return octets; |
| 197 | } |
| 198 | |
| 199 | public int size() { |
| 200 | return labels.size(); |
| 201 | } |
| 202 | |
| 203 | public boolean isEmpty() { |
| 204 | return (size() == 0); |
| 205 | } |
| 206 | |
| 207 | public int hashCode() { |
| 208 | int h = 0; |
| 209 | for (int i = 0; i < size(); i++) { |
| 210 | h = 31 * h + getKey(i).hashCode(); |
| 211 | } |
| 212 | return h; |
| 213 | } |
| 214 | |
| 215 | public boolean equals(Object obj) { |
| 216 | if (!(obj instanceof Name) || (obj instanceof CompositeName)) { |
| 217 | return false; |
| 218 | } |
| 219 | Name n = (Name) obj; |
| 220 | return ((size() == n.size()) && // shortcut: do sizes differ? |
| 221 | (compareTo(obj) == 0)); |
| 222 | } |
| 223 | |
| 224 | public int compareTo(Object obj) { |
| 225 | Name n = (Name) obj; |
| 226 | return compareRange(0, size(), n); // never 0 if sizes differ |
| 227 | } |
| 228 | |
| 229 | public boolean startsWith(Name n) { |
| 230 | return ((size() >= n.size()) && |
| 231 | (compareRange(0, n.size(), n) == 0)); |
| 232 | } |
| 233 | |
| 234 | public boolean endsWith(Name n) { |
| 235 | return ((size() >= n.size()) && |
| 236 | (compareRange(size() - n.size(), size(), n) == 0)); |
| 237 | } |
| 238 | |
| 239 | public String get(int pos) { |
| 240 | if (pos < 0 || pos >= size()) { |
| 241 | throw new ArrayIndexOutOfBoundsException(); |
| 242 | } |
| 243 | int i = size() - pos - 1; // index of "pos" component in "labels" |
| 244 | return (String) labels.get(i); |
| 245 | } |
| 246 | |
| 247 | public Enumeration getAll() { |
| 248 | return new Enumeration() { |
| 249 | int pos = 0; |
| 250 | public boolean hasMoreElements() { |
| 251 | return (pos < size()); |
| 252 | } |
| 253 | public Object nextElement() { |
| 254 | if (pos < size()) { |
| 255 | return get(pos++); |
| 256 | } |
| 257 | throw new java.util.NoSuchElementException(); |
| 258 | } |
| 259 | }; |
| 260 | } |
| 261 | |
| 262 | public Name getPrefix(int pos) { |
| 263 | return new DnsName(this, 0, pos); |
| 264 | } |
| 265 | |
| 266 | public Name getSuffix(int pos) { |
| 267 | return new DnsName(this, pos, size()); |
| 268 | } |
| 269 | |
| 270 | public Object clone() { |
| 271 | return new DnsName(this, 0, size()); |
| 272 | } |
| 273 | |
| 274 | public Object remove(int pos) { |
| 275 | if (pos < 0 || pos >= size()) { |
| 276 | throw new ArrayIndexOutOfBoundsException(); |
| 277 | } |
| 278 | int i = size() - pos - 1; // index of element to remove in "labels" |
| 279 | String label = (String) labels.remove(i); |
| 280 | int len = label.length(); |
| 281 | if (len > 0) { |
| 282 | octets -= (short) (len + 1); |
| 283 | } |
| 284 | domain = null; // invalidate "domain" |
| 285 | return label; |
| 286 | } |
| 287 | |
| 288 | public Name add(String comp) throws InvalidNameException { |
| 289 | return add(size(), comp); |
| 290 | } |
| 291 | |
| 292 | public Name add(int pos, String comp) throws InvalidNameException { |
| 293 | if (pos < 0 || pos > size()) { |
| 294 | throw new ArrayIndexOutOfBoundsException(); |
| 295 | } |
| 296 | // Check for empty labels: may have only one, and only at end. |
| 297 | int len = comp.length(); |
| 298 | if ((pos > 0 && len == 0) || |
| 299 | (pos == 0 && hasRootLabel())) { |
| 300 | throw new InvalidNameException( |
| 301 | "Empty label must be the last label in a domain name"); |
| 302 | } |
| 303 | // Check total name length. |
| 304 | if (len > 0) { |
| 305 | if (octets + len + 1 >= 256) { |
| 306 | throw new InvalidNameException("Name too long"); |
| 307 | } |
| 308 | octets += (short) (len + 1); |
| 309 | } |
| 310 | |
| 311 | int i = size() - pos; // index for insertion into "labels" |
| 312 | verifyLabel(comp); |
| 313 | labels.add(i, comp); |
| 314 | |
| 315 | domain = null; // invalidate "domain" |
| 316 | return this; |
| 317 | } |
| 318 | |
| 319 | public Name addAll(Name suffix) throws InvalidNameException { |
| 320 | return addAll(size(), suffix); |
| 321 | } |
| 322 | |
| 323 | public Name addAll(int pos, Name n) throws InvalidNameException { |
| 324 | if (n instanceof DnsName) { |
| 325 | // "n" is a DnsName so we can insert it as a whole, rather than |
| 326 | // verifying and inserting it component-by-component. |
| 327 | // More code, but less work. |
| 328 | DnsName dn = (DnsName) n; |
| 329 | |
| 330 | if (dn.isEmpty()) { |
| 331 | return this; |
| 332 | } |
| 333 | // Check for empty labels: may have only one, and only at end. |
| 334 | if ((pos > 0 && dn.hasRootLabel()) || |
| 335 | (pos == 0 && hasRootLabel())) { |
| 336 | throw new InvalidNameException( |
| 337 | "Empty label must be the last label in a domain name"); |
| 338 | } |
| 339 | |
| 340 | short newOctets = (short) (octets + dn.octets - 1); |
| 341 | if (newOctets > 255) { |
| 342 | throw new InvalidNameException("Name too long"); |
| 343 | } |
| 344 | octets = newOctets; |
| 345 | int i = size() - pos; // index for insertion into "labels" |
| 346 | labels.addAll(i, dn.labels); |
| 347 | |
| 348 | // Preserve "domain" if we're appending or prepending, |
| 349 | // otherwise invalidate it. |
| 350 | if (isEmpty()) { |
| 351 | domain = dn.domain; |
| 352 | } else if (domain == null || dn.domain == null) { |
| 353 | domain = null; |
| 354 | } else if (pos == 0) { |
| 355 | domain += (dn.domain.equals(".") ? "" : ".") + dn.domain; |
| 356 | } else if (pos == size()) { |
| 357 | domain = dn.domain + (domain.equals(".") ? "" : ".") + domain; |
| 358 | } else { |
| 359 | domain = null; |
| 360 | } |
| 361 | |
| 362 | } else if (n instanceof CompositeName) { |
| 363 | n = (DnsName) n; // force ClassCastException |
| 364 | |
| 365 | } else { // "n" is a compound name, but not a DnsName. |
| 366 | // Add labels least-significant first: sometimes more efficient. |
| 367 | for (int i = n.size() - 1; i >= 0; i--) { |
| 368 | add(pos, n.get(i)); |
| 369 | } |
| 370 | } |
| 371 | return this; |
| 372 | } |
| 373 | |
| 374 | |
| 375 | boolean hasRootLabel() { |
| 376 | return (!isEmpty() && |
| 377 | get(0).equals("")); |
| 378 | } |
| 379 | |
| 380 | /* |
| 381 | * Helper method for public comparison methods. Lexicographically |
| 382 | * compares components of this name in the range [beg,end) with |
| 383 | * all components of "n". Indexing is as for the Name interface, |
| 384 | * with 0 being the most significant. Returns negative, zero, or |
| 385 | * positive as these name components are less than, equal to, or |
| 386 | * greater than those of "n". |
| 387 | */ |
| 388 | private int compareRange(int beg, int end, Name n) { |
| 389 | if (n instanceof CompositeName) { |
| 390 | n = (DnsName) n; // force ClassCastException |
| 391 | } |
| 392 | // Loop through labels, starting with most significant. |
| 393 | int minSize = Math.min(end - beg, n.size()); |
| 394 | for (int i = 0; i < minSize; i++) { |
| 395 | String label1 = get(i + beg); |
| 396 | String label2 = n.get(i); |
| 397 | |
| 398 | int j = size() - (i + beg) - 1; // index of label1 in "labels" |
| 399 | // assert (label1 == labels.get(j)); |
| 400 | |
| 401 | int c = compareLabels(label1, label2); |
| 402 | if (c != 0) { |
| 403 | return c; |
| 404 | } |
| 405 | } |
| 406 | return ((end - beg) - n.size()); // longer range wins |
| 407 | } |
| 408 | |
| 409 | /* |
| 410 | * Returns a key suitable for hashing the label at index i. |
| 411 | * Indexing is as for the Name interface, with 0 being the most |
| 412 | * significant. |
| 413 | */ |
| 414 | String getKey(int i) { |
| 415 | return keyForLabel(get(i)); |
| 416 | } |
| 417 | |
| 418 | |
| 419 | /* |
| 420 | * Parses a domain name, setting the values of instance vars accordingly. |
| 421 | */ |
| 422 | private void parse(String name) throws InvalidNameException { |
| 423 | |
| 424 | StringBuffer label = new StringBuffer(); // label being parsed |
| 425 | |
| 426 | for (int i = 0; i < name.length(); i++) { |
| 427 | char c = name.charAt(i); |
| 428 | |
| 429 | if (c == '\\') { // found an escape sequence |
| 430 | c = getEscapedOctet(name, i++); |
| 431 | if (isDigit(name.charAt(i))) { // sequence is \DDD |
| 432 | i += 2; // consume remaining digits |
| 433 | } |
| 434 | label.append(c); |
| 435 | |
| 436 | } else if (c != '.') { // an unescaped octet |
| 437 | label.append(c); |
| 438 | |
| 439 | } else { // found '.' separator |
| 440 | add(0, label.toString()); // check syntax, then add label |
| 441 | // to end of name |
| 442 | label.delete(0, i); // clear buffer for next label |
| 443 | } |
| 444 | } |
| 445 | |
| 446 | // If name is neither "." nor "", the octets (zero or more) |
| 447 | // from the rightmost dot onward are now added as the final |
| 448 | // label of the name. Those two are special cases in that for |
| 449 | // all other domain names, the number of labels is one greater |
| 450 | // than the number of dot separators. |
| 451 | if (!name.equals("") && !name.equals(".")) { |
| 452 | add(0, label.toString()); |
| 453 | } |
| 454 | |
| 455 | domain = name; // do this last, since add() sets it to null |
| 456 | } |
| 457 | |
| 458 | /* |
| 459 | * Returns (as a char) the octet indicated by the escape sequence |
| 460 | * at a given position within a domain name. |
| 461 | * @throws InvalidNameException if a valid escape sequence is not found. |
| 462 | */ |
| 463 | private static char getEscapedOctet(String name, int pos) |
| 464 | throws InvalidNameException { |
| 465 | try { |
| 466 | // assert (name.charAt(pos) == '\\'); |
| 467 | char c1 = name.charAt(++pos); |
| 468 | if (isDigit(c1)) { // sequence is `\DDD' |
| 469 | char c2 = name.charAt(++pos); |
| 470 | char c3 = name.charAt(++pos); |
| 471 | if (isDigit(c2) && isDigit(c3)) { |
| 472 | return (char) |
| 473 | ((c1 - '0') * 100 + (c2 - '0') * 10 + (c3 - '0')); |
| 474 | } else { |
| 475 | throw new InvalidNameException( |
| 476 | "Invalid escape sequence in " + name); |
| 477 | } |
| 478 | } else { // sequence is `\C' |
| 479 | return c1; |
| 480 | } |
| 481 | } catch (IndexOutOfBoundsException e) { |
| 482 | throw new InvalidNameException( |
| 483 | "Invalid escape sequence in " + name); |
| 484 | } |
| 485 | } |
| 486 | |
| 487 | /* |
| 488 | * Checks that this label is valid. |
| 489 | * @throws InvalidNameException if label is not valid. |
| 490 | */ |
| 491 | private static void verifyLabel(String label) throws InvalidNameException { |
| 492 | if (label.length() > 63) { |
| 493 | throw new InvalidNameException( |
| 494 | "Label exceeds 63 octets: " + label); |
| 495 | } |
| 496 | // Check for two-byte characters. |
| 497 | for (int i = 0; i < label.length(); i++) { |
| 498 | char c = label.charAt(i); |
| 499 | if ((c & 0xFF00) != 0) { |
| 500 | throw new InvalidNameException( |
| 501 | "Label has two-byte char: " + label); |
| 502 | } |
| 503 | } |
| 504 | } |
| 505 | |
| 506 | /* |
| 507 | * Does this label conform to host name syntax? |
| 508 | */ |
| 509 | private static boolean isHostNameLabel(String label) { |
| 510 | for (int i = 0; i < label.length(); i++) { |
| 511 | char c = label.charAt(i); |
| 512 | if (!isHostNameChar(c)) { |
| 513 | return false; |
| 514 | } |
| 515 | } |
| 516 | return !(label.startsWith("-") || label.endsWith("-")); |
| 517 | } |
| 518 | |
| 519 | private static boolean isHostNameChar(char c) { |
| 520 | return (c == '-' || |
| 521 | c >= 'a' && c <= 'z' || |
| 522 | c >= 'A' && c <= 'Z' || |
| 523 | c >= '0' && c <= '9'); |
| 524 | } |
| 525 | |
| 526 | private static boolean isDigit(char c) { |
| 527 | return (c >= '0' && c <= '9'); |
| 528 | } |
| 529 | |
| 530 | /* |
| 531 | * Append a label to buf, escaping as needed. |
| 532 | */ |
| 533 | private static void escape(StringBuffer buf, String label) { |
| 534 | for (int i = 0; i < label.length(); i++) { |
| 535 | char c = label.charAt(i); |
| 536 | if (c == '.' || c == '\\') { |
| 537 | buf.append('\\'); |
| 538 | } |
| 539 | buf.append(c); |
| 540 | } |
| 541 | } |
| 542 | |
| 543 | /* |
| 544 | * Compares two labels, ignoring case for ASCII values. |
| 545 | * Returns negative, zero, or positive as the first label |
| 546 | * is less than, equal to, or greater than the second. |
| 547 | * See keyForLabel(). |
| 548 | */ |
| 549 | private static int compareLabels(String label1, String label2) { |
| 550 | int min = Math.min(label1.length(), label2.length()); |
| 551 | for (int i = 0; i < min; i++) { |
| 552 | char c1 = label1.charAt(i); |
| 553 | char c2 = label2.charAt(i); |
| 554 | if (c1 >= 'A' && c1 <= 'Z') { |
| 555 | c1 += 'a' - 'A'; // to lower case |
| 556 | } |
| 557 | if (c2 >= 'A' && c2 <= 'Z') { |
| 558 | c2 += 'a' - 'A'; // to lower case |
| 559 | } |
| 560 | if (c1 != c2) { |
| 561 | return (c1 - c2); |
| 562 | } |
| 563 | } |
| 564 | return (label1.length() - label2.length()); // the longer one wins |
| 565 | } |
| 566 | |
| 567 | /* |
| 568 | * Returns a key suitable for hashing a label. Two labels map to |
| 569 | * the same key iff they are equal, taking possible case-folding |
| 570 | * into account. See compareLabels(). |
| 571 | */ |
| 572 | private static String keyForLabel(String label) { |
| 573 | StringBuffer buf = new StringBuffer(label.length()); |
| 574 | for (int i = 0; i < label.length(); i++) { |
| 575 | char c = label.charAt(i); |
| 576 | if (c >= 'A' && c <= 'Z') { |
| 577 | c += 'a' - 'A'; // to lower case |
| 578 | } |
| 579 | buf.append(c); |
| 580 | } |
| 581 | return buf.toString(); |
| 582 | } |
| 583 | |
| 584 | |
| 585 | /** |
| 586 | * Serializes only the domain name string, for compactness and to avoid |
| 587 | * any implementation dependency. |
| 588 | * |
| 589 | * @serialdata The domain name string. |
| 590 | */ |
| 591 | private void writeObject(java.io.ObjectOutputStream s) |
| 592 | throws java.io.IOException { |
| 593 | s.writeObject(toString()); |
| 594 | } |
| 595 | |
| 596 | private void readObject(java.io.ObjectInputStream s) |
| 597 | throws java.io.IOException, ClassNotFoundException { |
| 598 | try { |
| 599 | parse((String) s.readObject()); |
| 600 | } catch (InvalidNameException e) { |
| 601 | // shouldn't happen |
| 602 | throw new java.io.StreamCorruptedException( |
| 603 | "Invalid name: " + domain); |
| 604 | } |
| 605 | } |
| 606 | |
| 607 | private static final long serialVersionUID = 7040187611324710271L; |
| 608 | } |