1 /*
2 * Copyright (c) 1997, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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5 * This code is free software; you can redistribute it and/or modify it
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25
26 /*
27 * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
28 * (C) Copyright IBM Corp. 1996-1998 - All Rights Reserved
29 *
30 * The original version of this source code and documentation is copyrighted
31 * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
32 * materials are provided under terms of a License Agreement between Taligent
33 * and Sun. This technology is protected by multiple US and International
34 * patents. This notice and attribution to Taligent may not be removed.
35 * Taligent is a registered trademark of Taligent, Inc.
36 *
37 */
38
39 package java.text;
40
41 import java.text.Normalizer;
42 import java.util.Vector;
43 import java.util.Locale;
44
45 /**
46 * The {@code RuleBasedCollator} class is a concrete subclass of
47 * {@code Collator} that provides a simple, data-driven, table
48 * collator. With this class you can create a customized table-based
49 * {@code Collator}. {@code RuleBasedCollator} maps
50 * characters to sort keys.
51 *
52 * <p>
53 * {@code RuleBasedCollator} has the following restrictions
54 * for efficiency (other subclasses may be used for more complex languages) :
55 * <ol>
56 * <li>If a special collation rule controlled by a <modifier> is
57 * specified it applies to the whole collator object.
58 * <li>All non-mentioned characters are at the end of the
59 * collation order.
60 * </ol>
61 *
62 * <p>
63 * The collation table is composed of a list of collation rules, where each
64 * rule is of one of three forms:
65 * <pre>
66 * <modifier>
67 * <relation> <text-argument>
68 * <reset> <text-argument>
69 * </pre>
70 * The definitions of the rule elements is as follows:
71 * <UL>
72 * <LI><strong>Text-Argument</strong>: A text-argument is any sequence of
73 * characters, excluding special characters (that is, common
74 * whitespace characters [0009-000D, 0020] and rule syntax characters
75 * [0021-002F, 003A-0040, 005B-0060, 007B-007E]). If those
76 * characters are desired, you can put them in single quotes
77 * (e.g. ampersand => '&'). Note that unquoted white space characters
78 * are ignored; e.g. {@code b c} is treated as {@code bc}.
79 * <LI><strong>Modifier</strong>: There are currently two modifiers that
80 * turn on special collation rules.
81 * <UL>
82 * <LI>'@' : Turns on backwards sorting of accents (secondary
83 * differences), as in French.
84 * <LI>'!' : Turns on Thai/Lao vowel-consonant swapping. If this
85 * rule is in force when a Thai vowel of the range
86 * \U0E40-\U0E44 precedes a Thai consonant of the range
87 * \U0E01-\U0E2E OR a Lao vowel of the range \U0EC0-\U0EC4
88 * precedes a Lao consonant of the range \U0E81-\U0EAE then
89 * the vowel is placed after the consonant for collation
90 * purposes.
91 * </UL>
92 * <p>'@' : Indicates that accents are sorted backwards, as in French.
93 * <LI><strong>Relation</strong>: The relations are the following:
94 * <UL>
95 * <LI>'<' : Greater, as a letter difference (primary)
96 * <LI>';' : Greater, as an accent difference (secondary)
97 * <LI>',' : Greater, as a case difference (tertiary)
98 * <LI>'=' : Equal
99 * </UL>
100 * <LI><strong>Reset</strong>: There is a single reset
101 * which is used primarily for contractions and expansions, but which
102 * can also be used to add a modification at the end of a set of rules.
103 * <p>'&' : Indicates that the next rule follows the position to where
104 * the reset text-argument would be sorted.
105 * </UL>
106 *
107 * <p>
108 * This sounds more complicated than it is in practice. For example, the
109 * following are equivalent ways of expressing the same thing:
110 * <blockquote>
111 * <pre>
112 * a < b < c
113 * a < b & b < c
114 * a < c & a < b
115 * </pre>
116 * </blockquote>
117 * Notice that the order is important, as the subsequent item goes immediately
118 * after the text-argument. The following are not equivalent:
119 * <blockquote>
120 * <pre>
121 * a < b & a < c
122 * a < c & a < b
123 * </pre>
124 * </blockquote>
125 * Either the text-argument must already be present in the sequence, or some
126 * initial substring of the text-argument must be present. (e.g. "a < b & ae <
127 * e" is valid since "a" is present in the sequence before "ae" is reset). In
128 * this latter case, "ae" is not entered and treated as a single character;
129 * instead, "e" is sorted as if it were expanded to two characters: "a"
130 * followed by an "e". This difference appears in natural languages: in
131 * traditional Spanish "ch" is treated as though it contracts to a single
132 * character (expressed as "c < ch < d"), while in traditional German
133 * a-umlaut is treated as though it expanded to two characters
134 * (expressed as "a,A < b,B ... &ae;\u00e3&AE;\u00c3").
135 * [\u00e3 and \u00c3 are, of course, the escape sequences for a-umlaut.]
136 * <p>
137 * <strong>Ignorable Characters</strong>
138 * <p>
139 * For ignorable characters, the first rule must start with a relation (the
140 * examples we have used above are really fragments; "a < b" really should be
141 * "< a < b"). If, however, the first relation is not "<", then all the all
142 * text-arguments up to the first "<" are ignorable. For example, ", - < a < b"
143 * makes "-" an ignorable character, as we saw earlier in the word
144 * "black-birds". In the samples for different languages, you see that most
145 * accents are ignorable.
146 *
147 * <p><strong>Normalization and Accents</strong>
148 * <p>
149 * {@code RuleBasedCollator} automatically processes its rule table to
150 * include both pre-composed and combining-character versions of
151 * accented characters. Even if the provided rule string contains only
152 * base characters and separate combining accent characters, the pre-composed
153 * accented characters matching all canonical combinations of characters from
154 * the rule string will be entered in the table.
155 * <p>
156 * This allows you to use a RuleBasedCollator to compare accented strings
157 * even when the collator is set to NO_DECOMPOSITION. There are two caveats,
158 * however. First, if the strings to be collated contain combining
159 * sequences that may not be in canonical order, you should set the collator to
160 * CANONICAL_DECOMPOSITION or FULL_DECOMPOSITION to enable sorting of
161 * combining sequences. Second, if the strings contain characters with
162 * compatibility decompositions (such as full-width and half-width forms),
163 * you must use FULL_DECOMPOSITION, since the rule tables only include
164 * canonical mappings.
165 *
166 * <p><strong>Errors</strong>
167 * <p>
168 * The following are errors:
169 * <UL>
170 * <LI>A text-argument contains unquoted punctuation symbols
171 * (e.g. "a < b-c < d").
172 * <LI>A relation or reset character not followed by a text-argument
173 * (e.g. "a < ,b").
174 * <LI>A reset where the text-argument (or an initial substring of the
175 * text-argument) is not already in the sequence.
176 * (e.g. "a < b & e < f")
177 * </UL>
178 * If you produce one of these errors, a {@code RuleBasedCollator} throws
179 * a {@code ParseException}.
180 *
181 * <p><strong>Examples</strong>
182 * <p>Simple: "< a < b < c < d"
183 * <p>Norwegian: "< a, A < b, B < c, C < d, D < e, E < f, F
184 * < g, G < h, H < i, I < j, J < k, K < l, L
185 * < m, M < n, N < o, O < p, P < q, Q < r, R
186 * < s, S < t, T < u, U < v, V < w, W < x, X
187 * < y, Y < z, Z
188 * < \u00E6, \u00C6
189 * < \u00F8, \u00D8
190 * < \u00E5 = a\u030A, \u00C5 = A\u030A;
191 * aa, AA"
192 *
193 * <p>
194 * To create a {@code RuleBasedCollator} object with specialized
195 * rules tailored to your needs, you construct the {@code RuleBasedCollator}
196 * with the rules contained in a {@code String} object. For example:
197 * <blockquote>
198 * <pre>
199 * String simple = "< a< b< c< d";
200 * RuleBasedCollator mySimple = new RuleBasedCollator(simple);
201 * </pre>
202 * </blockquote>
203 * Or:
204 * <blockquote>
205 * <pre>
206 * String Norwegian = "< a, A < b, B < c, C < d, D < e, E < f, F < g, G < h, H < i, I" +
207 * "< j, J < k, K < l, L < m, M < n, N < o, O < p, P < q, Q < r, R" +
208 * "< s, S < t, T < u, U < v, V < w, W < x, X < y, Y < z, Z" +
209 * "< \u00E6, \u00C6" + // Latin letter ae & AE
210 * "< \u00F8, \u00D8" + // Latin letter o & O with stroke
211 * "< \u00E5 = a\u030A," + // Latin letter a with ring above
212 * " \u00C5 = A\u030A;" + // Latin letter A with ring above
213 * " aa, AA";
214 * RuleBasedCollator myNorwegian = new RuleBasedCollator(Norwegian);
215 * </pre>
216 * </blockquote>
217 *
218 * <p>
219 * A new collation rules string can be created by concatenating rules
220 * strings. For example, the rules returned by {@link #getRules()} could
221 * be concatenated to combine multiple {@code RuleBasedCollator}s.
222 *
223 * <p>
224 * The following example demonstrates how to change the order of
225 * non-spacing accents,
226 * <blockquote>
227 * <pre>
228 * // old rule
229 * String oldRules = "=\u0301;\u0300;\u0302;\u0308" // main accents
230 * + ";\u0327;\u0303;\u0304;\u0305" // main accents
231 * + ";\u0306;\u0307;\u0309;\u030A" // main accents
232 * + ";\u030B;\u030C;\u030D;\u030E" // main accents
233 * + ";\u030F;\u0310;\u0311;\u0312" // main accents
234 * + "< a , A ; ae, AE ; \u00e6 , \u00c6"
235 * + "< b , B < c, C < e, E & C < d, D";
236 * // change the order of accent characters
237 * String addOn = "& \u0300 ; \u0308 ; \u0302";
238 * RuleBasedCollator myCollator = new RuleBasedCollator(oldRules + addOn);
239 * </pre>
240 * </blockquote>
241 *
242 * @see Collator
243 * @see CollationElementIterator
244 * @author Helena Shih, Laura Werner, Richard Gillam
245 * @since 1.1
246 */
247 public class RuleBasedCollator extends Collator{
248 // IMPLEMENTATION NOTES: The implementation of the collation algorithm is
249 // divided across three classes: RuleBasedCollator, RBCollationTables, and
250 // CollationElementIterator. RuleBasedCollator contains the collator's
251 // transient state and includes the code that uses the other classes to
252 // implement comparison and sort-key building. RuleBasedCollator also
253 // contains the logic to handle French secondary accent sorting.
254 // A RuleBasedCollator has two CollationElementIterators. State doesn't
255 // need to be preserved in these objects between calls to compare() or
256 // getCollationKey(), but the objects persist anyway to avoid wasting extra
257 // creation time. compare() and getCollationKey() are synchronized to ensure
258 // thread safety with this scheme. The CollationElementIterator is responsible
259 // for generating collation elements from strings and returning one element at
260 // a time (sometimes there's a one-to-many or many-to-one mapping between
261 // characters and collation elements-- this class handles that).
262 // CollationElementIterator depends on RBCollationTables, which contains the
263 // collator's static state. RBCollationTables contains the actual data
264 // tables specifying the collation order of characters for a particular locale
265 // or use. It also contains the base logic that CollationElementIterator
266 // uses to map from characters to collation elements. A single RBCollationTables
267 // object is shared among all RuleBasedCollators for the same locale, and
268 // thus by all the CollationElementIterators they create.
269
270 /**
271 * RuleBasedCollator constructor. This takes the table rules and builds
272 * a collation table out of them. Please see RuleBasedCollator class
273 * description for more details on the collation rule syntax.
274 * @see java.util.Locale
275 * @param rules the collation rules to build the collation table from.
276 * @throws ParseException A format exception
277 * will be thrown if the build process of the rules fails. For
278 * example, build rule "a < ? < d" will cause the constructor to
279 * throw the ParseException because the '?' is not quoted.
280 */
281 public RuleBasedCollator(String rules) throws ParseException {
282 this(rules, Collator.CANONICAL_DECOMPOSITION);
283 }
284
285 /**
286 * RuleBasedCollator constructor. This takes the table rules and builds
287 * a collation table out of them. Please see RuleBasedCollator class
288 * description for more details on the collation rule syntax.
289 * @see java.util.Locale
290 * @param rules the collation rules to build the collation table from.
291 * @param decomp the decomposition strength used to build the
292 * collation table and to perform comparisons.
293 * @throws ParseException A format exception
294 * will be thrown if the build process of the rules fails. For
295 * example, build rule "a < ? < d" will cause the constructor to
296 * throw the ParseException because the '?' is not quoted.
297 */
298 RuleBasedCollator(String rules, int decomp) throws ParseException {
299 setStrength(Collator.TERTIARY);
300 setDecomposition(decomp);
301 tables = new RBCollationTables(rules, decomp);
302 }
303
304 /**
305 * "Copy constructor." Used in clone() for performance.
306 */
307 private RuleBasedCollator(RuleBasedCollator that) {
308 setStrength(that.getStrength());
309 setDecomposition(that.getDecomposition());
310 tables = that.tables;
311 }
312
313 /**
314 * Gets the table-based rules for the collation object.
315 * @return returns the collation rules that the table collation object
316 * was created from.
317 */
318 public String getRules()
319 {
320 return tables.getRules();
321 }
322
323 /**
324 * Returns a CollationElementIterator for the given String.
325 *
326 * @param source the string to be collated
327 * @return a {@code CollationElementIterator} object
328 * @see java.text.CollationElementIterator
329 */
330 public CollationElementIterator getCollationElementIterator(String source) {
331 return new CollationElementIterator( source, this );
332 }
333
334 /**
335 * Returns a CollationElementIterator for the given CharacterIterator.
336 *
337 * @param source the character iterator to be collated
338 * @return a {@code CollationElementIterator} object
339 * @see java.text.CollationElementIterator
340 * @since 1.2
341 */
342 public CollationElementIterator getCollationElementIterator(
343 CharacterIterator source) {
344 return new CollationElementIterator( source, this );
345 }
346
347 /**
348 * Compares the character data stored in two different strings based on the
349 * collation rules. Returns information about whether a string is less
350 * than, greater than or equal to another string in a language.
351 * This can be overridden in a subclass.
352 *
353 * @throws NullPointerException if {@code source} or {@code target} is null.
354 */
355 public synchronized int compare(String source, String target)
356 {
357 if (source == null || target == null) {
358 throw new NullPointerException();
359 }
360
361 // The basic algorithm here is that we use CollationElementIterators
362 // to step through both the source and target strings. We compare each
363 // collation element in the source string against the corresponding one
364 // in the target, checking for differences.
365 //
366 // If a difference is found, we set <result> to LESS or GREATER to
367 // indicate whether the source string is less or greater than the target.
368 //
369 // However, it's not that simple. If we find a tertiary difference
370 // (e.g. 'A' vs. 'a') near the beginning of a string, it can be
371 // overridden by a primary difference (e.g. "A" vs. "B") later in
372 // the string. For example, "AA" < "aB", even though 'A' > 'a'.
373 //
374 // To keep track of this, we use strengthResult to keep track of the
375 // strength of the most significant difference that has been found
376 // so far. When we find a difference whose strength is greater than
377 // strengthResult, it overrides the last difference (if any) that
378 // was found.
379
380 int result = Collator.EQUAL;
381
382 if (sourceCursor == null) {
383 sourceCursor = getCollationElementIterator(source);
384 } else {
385 sourceCursor.setText(source);
386 }
387 if (targetCursor == null) {
388 targetCursor = getCollationElementIterator(target);
389 } else {
390 targetCursor.setText(target);
391 }
392
393 int sOrder = 0, tOrder = 0;
394
395 boolean initialCheckSecTer = getStrength() >= Collator.SECONDARY;
396 boolean checkSecTer = initialCheckSecTer;
397 boolean checkTertiary = getStrength() >= Collator.TERTIARY;
398
399 boolean gets = true, gett = true;
400
401 while(true) {
402 // Get the next collation element in each of the strings, unless
403 // we've been requested to skip it.
404 if (gets) sOrder = sourceCursor.next(); else gets = true;
405 if (gett) tOrder = targetCursor.next(); else gett = true;
406
407 // If we've hit the end of one of the strings, jump out of the loop
408 if ((sOrder == CollationElementIterator.NULLORDER)||
409 (tOrder == CollationElementIterator.NULLORDER))
410 break;
411
412 int pSOrder = CollationElementIterator.primaryOrder(sOrder);
413 int pTOrder = CollationElementIterator.primaryOrder(tOrder);
414
415 // If there's no difference at this position, we can skip it
416 if (sOrder == tOrder) {
417 if (tables.isFrenchSec() && pSOrder != 0) {
418 if (!checkSecTer) {
419 // in french, a secondary difference more to the right is stronger,
420 // so accents have to be checked with each base element
421 checkSecTer = initialCheckSecTer;
422 // but tertiary differences are less important than the first
423 // secondary difference, so checking tertiary remains disabled
424 checkTertiary = false;
425 }
426 }
427 continue;
428 }
429
430 // Compare primary differences first.
431 if ( pSOrder != pTOrder )
432 {
433 if (sOrder == 0) {
434 // The entire source element is ignorable.
435 // Skip to the next source element, but don't fetch another target element.
436 gett = false;
437 continue;
438 }
439 if (tOrder == 0) {
440 gets = false;
441 continue;
442 }
443
444 // The source and target elements aren't ignorable, but it's still possible
445 // for the primary component of one of the elements to be ignorable....
446
447 if (pSOrder == 0) // primary order in source is ignorable
448 {
449 // The source's primary is ignorable, but the target's isn't. We treat ignorables
450 // as a secondary difference, so remember that we found one.
451 if (checkSecTer) {
452 result = Collator.GREATER; // (strength is SECONDARY)
453 checkSecTer = false;
454 }
455 // Skip to the next source element, but don't fetch another target element.
456 gett = false;
457 }
458 else if (pTOrder == 0)
459 {
460 // record differences - see the comment above.
461 if (checkSecTer) {
462 result = Collator.LESS; // (strength is SECONDARY)
463 checkSecTer = false;
464 }
465 // Skip to the next source element, but don't fetch another target element.
466 gets = false;
467 } else {
468 // Neither of the orders is ignorable, and we already know that the primary
469 // orders are different because of the (pSOrder != pTOrder) test above.
470 // Record the difference and stop the comparison.
471 if (pSOrder < pTOrder) {
472 return Collator.LESS; // (strength is PRIMARY)
473 } else {
474 return Collator.GREATER; // (strength is PRIMARY)
475 }
476 }
477 } else { // else of if ( pSOrder != pTOrder )
478 // primary order is the same, but complete order is different. So there
479 // are no base elements at this point, only ignorables (Since the strings are
480 // normalized)
481
482 if (checkSecTer) {
483 // a secondary or tertiary difference may still matter
484 short secSOrder = CollationElementIterator.secondaryOrder(sOrder);
485 short secTOrder = CollationElementIterator.secondaryOrder(tOrder);
486 if (secSOrder != secTOrder) {
487 // there is a secondary difference
488 result = (secSOrder < secTOrder) ? Collator.LESS : Collator.GREATER;
489 // (strength is SECONDARY)
490 checkSecTer = false;
491 // (even in french, only the first secondary difference within
492 // a base character matters)
493 } else {
494 if (checkTertiary) {
495 // a tertiary difference may still matter
496 short terSOrder = CollationElementIterator.tertiaryOrder(sOrder);
497 short terTOrder = CollationElementIterator.tertiaryOrder(tOrder);
498 if (terSOrder != terTOrder) {
499 // there is a tertiary difference
500 result = (terSOrder < terTOrder) ? Collator.LESS : Collator.GREATER;
501 // (strength is TERTIARY)
502 checkTertiary = false;
503 }
504 }
505 }
506 } // if (checkSecTer)
507
508 } // if ( pSOrder != pTOrder )
509 } // while()
510
511 if (sOrder != CollationElementIterator.NULLORDER) {
512 // (tOrder must be CollationElementIterator::NULLORDER,
513 // since this point is only reached when sOrder or tOrder is NULLORDER.)
514 // The source string has more elements, but the target string hasn't.
515 do {
516 if (CollationElementIterator.primaryOrder(sOrder) != 0) {
517 // We found an additional non-ignorable base character in the source string.
518 // This is a primary difference, so the source is greater
519 return Collator.GREATER; // (strength is PRIMARY)
520 }
521 else if (CollationElementIterator.secondaryOrder(sOrder) != 0) {
522 // Additional secondary elements mean the source string is greater
523 if (checkSecTer) {
524 result = Collator.GREATER; // (strength is SECONDARY)
525 checkSecTer = false;
526 }
527 }
528 } while ((sOrder = sourceCursor.next()) != CollationElementIterator.NULLORDER);
529 }
530 else if (tOrder != CollationElementIterator.NULLORDER) {
531 // The target string has more elements, but the source string hasn't.
532 do {
533 if (CollationElementIterator.primaryOrder(tOrder) != 0)
534 // We found an additional non-ignorable base character in the target string.
535 // This is a primary difference, so the source is less
536 return Collator.LESS; // (strength is PRIMARY)
537 else if (CollationElementIterator.secondaryOrder(tOrder) != 0) {
538 // Additional secondary elements in the target mean the source string is less
539 if (checkSecTer) {
540 result = Collator.LESS; // (strength is SECONDARY)
541 checkSecTer = false;
542 }
543 }
544 } while ((tOrder = targetCursor.next()) != CollationElementIterator.NULLORDER);
545 }
546
547 // For IDENTICAL comparisons, we use a bitwise character comparison
548 // as a tiebreaker if all else is equal
549 if (result == 0 && getStrength() == IDENTICAL) {
550 int mode = getDecomposition();
551 Normalizer.Form form;
552 if (mode == CANONICAL_DECOMPOSITION) {
553 form = Normalizer.Form.NFD;
554 } else if (mode == FULL_DECOMPOSITION) {
555 form = Normalizer.Form.NFKD;
556 } else {
557 return source.compareTo(target);
558 }
559
560 String sourceDecomposition = Normalizer.normalize(source, form);
561 String targetDecomposition = Normalizer.normalize(target, form);
562 return sourceDecomposition.compareTo(targetDecomposition);
563 }
564 return result;
565 }
566
567 /**
568 * Transforms the string into a series of characters that can be compared
569 * with CollationKey.compareTo. This overrides java.text.Collator.getCollationKey.
570 * It can be overridden in a subclass.
571 */
572 public synchronized CollationKey getCollationKey(String source)
573 {
574 //
575 // The basic algorithm here is to find all of the collation elements for each
576 // character in the source string, convert them to a char representation,
577 // and put them into the collation key. But it's trickier than that.
578 // Each collation element in a string has three components: primary (A vs B),
579 // secondary (A vs A-acute), and tertiary (A' vs a); and a primary difference
580 // at the end of a string takes precedence over a secondary or tertiary
581 // difference earlier in the string.
582 //
583 // To account for this, we put all of the primary orders at the beginning of the
584 // string, followed by the secondary and tertiary orders, separated by nulls.
585 //
586 // Here's a hypothetical example, with the collation element represented as
587 // a three-digit number, one digit for primary, one for secondary, etc.
588 //
589 // String: A a B \u00e9 <--(e-acute)
590 // Collation Elements: 101 100 201 510
591 //
592 // Collation Key: 1125<null>0001<null>1010
593 //
594 // To make things even trickier, secondary differences (accent marks) are compared
595 // starting at the *end* of the string in languages with French secondary ordering.
596 // But when comparing the accent marks on a single base character, they are compared
597 // from the beginning. To handle this, we reverse all of the accents that belong
598 // to each base character, then we reverse the entire string of secondary orderings
599 // at the end. Taking the same example above, a French collator might return
600 // this instead:
601 //
602 // Collation Key: 1125<null>1000<null>1010
603 //
604 if (source == null)
605 return null;
606
607 if (primResult == null) {
608 primResult = new StringBuffer();
609 secResult = new StringBuffer();
610 terResult = new StringBuffer();
611 } else {
612 primResult.setLength(0);
613 secResult.setLength(0);
614 terResult.setLength(0);
615 }
616 int order = 0;
617 boolean compareSec = (getStrength() >= Collator.SECONDARY);
618 boolean compareTer = (getStrength() >= Collator.TERTIARY);
619 int secOrder = CollationElementIterator.NULLORDER;
620 int terOrder = CollationElementIterator.NULLORDER;
621 int preSecIgnore = 0;
622
623 if (sourceCursor == null) {
624 sourceCursor = getCollationElementIterator(source);
625 } else {
626 sourceCursor.setText(source);
627 }
628
629 // walk through each character
630 while ((order = sourceCursor.next()) !=
631 CollationElementIterator.NULLORDER)
632 {
633 secOrder = CollationElementIterator.secondaryOrder(order);
634 terOrder = CollationElementIterator.tertiaryOrder(order);
635 if (!CollationElementIterator.isIgnorable(order))
636 {
637 primResult.append((char) (CollationElementIterator.primaryOrder(order)
638 + COLLATIONKEYOFFSET));
639
640 if (compareSec) {
641 //
642 // accumulate all of the ignorable/secondary characters attached
643 // to a given base character
644 //
645 if (tables.isFrenchSec() && preSecIgnore < secResult.length()) {
646 //
647 // We're doing reversed secondary ordering and we've hit a base
648 // (non-ignorable) character. Reverse any secondary orderings
649 // that applied to the last base character. (see block comment above.)
650 //
651 RBCollationTables.reverse(secResult, preSecIgnore, secResult.length());
652 }
653 // Remember where we are in the secondary orderings - this is how far
654 // back to go if we need to reverse them later.
655 secResult.append((char)(secOrder+ COLLATIONKEYOFFSET));
656 preSecIgnore = secResult.length();
657 }
658 if (compareTer) {
659 terResult.append((char)(terOrder+ COLLATIONKEYOFFSET));
660 }
661 }
662 else
663 {
664 if (compareSec && secOrder != 0)
665 secResult.append((char)
666 (secOrder + tables.getMaxSecOrder() + COLLATIONKEYOFFSET));
667 if (compareTer && terOrder != 0)
668 terResult.append((char)
669 (terOrder + tables.getMaxTerOrder() + COLLATIONKEYOFFSET));
670 }
671 }
672 if (tables.isFrenchSec())
673 {
674 if (preSecIgnore < secResult.length()) {
675 // If we've accumulated any secondary characters after the last base character,
676 // reverse them.
677 RBCollationTables.reverse(secResult, preSecIgnore, secResult.length());
678 }
679 // And now reverse the entire secResult to get French secondary ordering.
680 RBCollationTables.reverse(secResult, 0, secResult.length());
681 }
682 primResult.append((char)0);
683 secResult.append((char)0);
684 secResult.append(terResult.toString());
685 primResult.append(secResult.toString());
686
687 if (getStrength() == IDENTICAL) {
688 primResult.append((char)0);
689 int mode = getDecomposition();
690 if (mode == CANONICAL_DECOMPOSITION) {
691 primResult.append(Normalizer.normalize(source, Normalizer.Form.NFD));
692 } else if (mode == FULL_DECOMPOSITION) {
693 primResult.append(Normalizer.normalize(source, Normalizer.Form.NFKD));
694 } else {
695 primResult.append(source);
696 }
697 }
698 return new RuleBasedCollationKey(source, primResult.toString());
699 }
700
701 /**
702 * Standard override; no change in semantics.
703 */
704 public Object clone() {
705 // if we know we're not actually a subclass of RuleBasedCollator
706 // (this class really should have been made final), bypass
707 // Object.clone() and use our "copy constructor". This is faster.
708 if (getClass() == RuleBasedCollator.class) {
709 return new RuleBasedCollator(this);
710 }
711 else {
712 RuleBasedCollator result = (RuleBasedCollator) super.clone();
713 result.primResult = null;
714 result.secResult = null;
715 result.terResult = null;
716 result.sourceCursor = null;
717 result.targetCursor = null;
718 return result;
719 }
720 }
721
722 /**
723 * Compares the equality of two collation objects.
724 * @param obj the table-based collation object to be compared with this.
725 * @return true if the current table-based collation object is the same
726 * as the table-based collation object obj; false otherwise.
727 */
728 public boolean equals(Object obj) {
729 if (obj == null) return false;
730 if (!super.equals(obj)) return false; // super does class check
731 RuleBasedCollator other = (RuleBasedCollator) obj;
732 // all other non-transient information is also contained in rules.
733 return (getRules().equals(other.getRules()));
734 }
735
736 /**
737 * Generates the hash code for the table-based collation object
738 */
739 public int hashCode() {
740 return getRules().hashCode();
741 }
742
743 /**
744 * Allows CollationElementIterator access to the tables object
745 */
746 RBCollationTables getTables() {
747 return tables;
748 }
749
750 // ==============================================================
751 // private
752 // ==============================================================
753
754 static final int CHARINDEX = 0x70000000; // need look up in .commit()
755 static final int EXPANDCHARINDEX = 0x7E000000; // Expand index follows
756 static final int CONTRACTCHARINDEX = 0x7F000000; // contract indexes follow
757 static final int UNMAPPED = 0xFFFFFFFF;
758
759 private static final int COLLATIONKEYOFFSET = 1;
760
761 private RBCollationTables tables = null;
762
763 // Internal objects that are cached across calls so that they don't have to
764 // be created/destroyed on every call to compare() and getCollationKey()
765 private StringBuffer primResult = null;
766 private StringBuffer secResult = null;
767 private StringBuffer terResult = null;
768 private CollationElementIterator sourceCursor = null;
769 private CollationElementIterator targetCursor = null;
770 }