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My first initial commit with all of mine experimental changes.

Dmitry Kabak (userdima committed 13 years ago

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1+/*
2+ * Copyright (c) 1997, 2010, Oracle and/or its affiliates. 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. Oracle designates this
8+ * particular file as subject to the "Classpath" exception as provided
9+ * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22+ * or visit www.oracle.com if you need additional information or have any
23+ * questions.
24+ */
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</code> class is a concrete subclass of
47+ * <code>Collator</code> that provides a simple, data-driven, table
48+ * collator. With this class you can create a customized table-based
49+ * <code>Collator</code>. <code>RuleBasedCollator</code> maps
50+ * characters to sort keys.
51+ *
52+ * <p>
53+ * <code>RuleBasedCollator</code> 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 &lt;modifier&gt; 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+ * &lt;modifier&gt;
67+ * &lt;relation&gt; &lt;text-argument&gt;
68+ * &lt;reset&gt; &lt;text-argument&gt;
69+ * </pre>
70+ * The definitions of the rule elements is as follows:
71+ * <UL Type=disc>
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</code> is treated as <code>bc</code>.
79+ * <LI><strong>Modifier</strong>: There are currently two modifiers that
80+ * turn on special collation rules.
81+ * <UL Type=square>
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+ * &#92;U0E40-&#92;U0E44 precedes a Thai consonant of the range
87+ * &#92;U0E01-&#92;U0E2E OR a Lao vowel of the range &#92;U0EC0-&#92;U0EC4
88+ * precedes a Lao consonant of the range &#92;U0E81-&#92;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 Type=square>
95+ * <LI>'&lt;' : 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 &lt; b &lt; c
113+ * a &lt; b &amp; b &lt; c
114+ * a &lt; c &amp; a &lt; 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 &lt; b &amp; a &lt; c
122+ * a &lt; c &amp; a &lt; 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 &lt; b &amp; ae &lt;
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 &lt; ch &lt; d"), while in traditional German
133+ * a-umlaut is treated as though it expanded to two characters
134+ * (expressed as "a,A &lt; b,B ... &amp;ae;&#92;u00e3&amp;AE;&#92;u00c3").
135+ * [&#92;u00e3 and &#92;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 &lt; b" really should be
141+ * "&lt; a &lt; b"). If, however, the first relation is not "&lt;", then all the all
142+ * text-arguments up to the first "&lt;" are ignorable. For example, ", - &lt; a &lt; 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</code> 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 Type=disc>
170+ * <LI>A text-argument contains unquoted punctuation symbols
171+ * (e.g. "a &lt; b-c &lt; d").
172+ * <LI>A relation or reset character not followed by a text-argument
173+ * (e.g. "a &lt; ,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 &lt; b &amp; e &lt; f")
177+ * </UL>
178+ * If you produce one of these errors, a <code>RuleBasedCollator</code> throws
179+ * a <code>ParseException</code>.
180+ *
181+ * <p><strong>Examples</strong>
182+ * <p>Simple: "&lt; a &lt; b &lt; c &lt; d"
183+ * <p>Norwegian: "&lt; a, A &lt; b, B &lt; c, C &lt; d, D &lt; e, E &lt; f, F
184+ * &lt; g, G &lt; h, H &lt; i, I &lt; j, J &lt; k, K &lt; l, L
185+ * &lt; m, M &lt; n, N &lt; o, O &lt; p, P &lt; q, Q &lt; r, R
186+ * &lt; s, S &lt; t, T &lt; u, U &lt; v, V &lt; w, W &lt; x, X
187+ * &lt; y, Y &lt; z, Z
188+ * &lt; &#92;u00E6, &#92;u00C6
189+ * &lt; &#92;u00F8, &#92;u00D8
190+ * &lt; &#92;u00E5 = a&#92;u030A, &#92;u00C5 = A&#92;u030A;
191+ * aa, AA"
192+ *
193+ * <p>
194+ * To create a <code>RuleBasedCollator</code> object with specialized
195+ * rules tailored to your needs, you construct the <code>RuleBasedCollator</code>
196+ * with the rules contained in a <code>String</code> object. For example:
197+ * <blockquote>
198+ * <pre>
199+ * String simple = "&lt; a&lt; b&lt; c&lt; d";
200+ * RuleBasedCollator mySimple = new RuleBasedCollator(simple);
201+ * </pre>
202+ * </blockquote>
203+ * Or:
204+ * <blockquote>
205+ * <pre>
206+ * String Norwegian = "&lt; a, A &lt; b, B &lt; c, C &lt; d, D &lt; e, E &lt; f, F &lt; g, G &lt; h, H &lt; i, I" +
207+ * "&lt; j, J &lt; k, K &lt; l, L &lt; m, M &lt; n, N &lt; o, O &lt; p, P &lt; q, Q &lt; r, R" +
208+ * "&lt; s, S &lt; t, T &lt; u, U &lt; v, V &lt; w, W &lt; x, X &lt; y, Y &lt; z, Z" +
209+ * "&lt; &#92;u00E6, &#92;u00C6" + // Latin letter ae & AE
210+ * "&lt; &#92;u00F8, &#92;u00D8" + // Latin letter o & O with stroke
211+ * "&lt; &#92;u00E5 = a&#92;u030A," + // Latin letter a with ring above
212+ * " &#92;u00C5 = A&#92;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</code>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 = "=&#92;u0301;&#92;u0300;&#92;u0302;&#92;u0308" // main accents
230+ * + ";&#92;u0327;&#92;u0303;&#92;u0304;&#92;u0305" // main accents
231+ * + ";&#92;u0306;&#92;u0307;&#92;u0309;&#92;u030A" // main accents
232+ * + ";&#92;u030B;&#92;u030C;&#92;u030D;&#92;u030E" // main accents
233+ * + ";&#92;u030F;&#92;u0310;&#92;u0311;&#92;u0312" // main accents
234+ * + "&lt; a , A ; ae, AE ; &#92;u00e6 , &#92;u00c6"
235+ * + "&lt; b , B &lt; c, C &lt; e, E & C &lt; d, D";
236+ * // change the order of accent characters
237+ * String addOn = "& &#92;u0300 ; &#92;u0308 ; &#92;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+ */
246+public class RuleBasedCollator extends Collator{
247+ // IMPLEMENTATION NOTES: The implementation of the collation algorithm is
248+ // divided across three classes: RuleBasedCollator, RBCollationTables, and
249+ // CollationElementIterator. RuleBasedCollator contains the collator's
250+ // transient state and includes the code that uses the other classes to
251+ // implement comparison and sort-key building. RuleBasedCollator also
252+ // contains the logic to handle French secondary accent sorting.
253+ // A RuleBasedCollator has two CollationElementIterators. State doesn't
254+ // need to be preserved in these objects between calls to compare() or
255+ // getCollationKey(), but the objects persist anyway to avoid wasting extra
256+ // creation time. compare() and getCollationKey() are synchronized to ensure
257+ // thread safety with this scheme. The CollationElementIterator is responsible
258+ // for generating collation elements from strings and returning one element at
259+ // a time (sometimes there's a one-to-many or many-to-one mapping between
260+ // characters and collation elements-- this class handles that).
261+ // CollationElementIterator depends on RBCollationTables, which contains the
262+ // collator's static state. RBCollationTables contains the actual data
263+ // tables specifying the collation order of characters for a particular locale
264+ // or use. It also contains the base logic that CollationElementIterator
265+ // uses to map from characters to collation elements. A single RBCollationTables
266+ // object is shared among all RuleBasedCollators for the same locale, and
267+ // thus by all the CollationElementIterators they create.
268+
269+ /**
270+ * RuleBasedCollator constructor. This takes the table rules and builds
271+ * a collation table out of them. Please see RuleBasedCollator class
272+ * description for more details on the collation rule syntax.
273+ * @see java.util.Locale
274+ * @param rules the collation rules to build the collation table from.
275+ * @exception ParseException A format exception
276+ * will be thrown if the build process of the rules fails. For
277+ * example, build rule "a < ? < d" will cause the constructor to
278+ * throw the ParseException because the '?' is not quoted.
279+ */
280+ public RuleBasedCollator(String rules) throws ParseException {
281+ this(rules, Collator.CANONICAL_DECOMPOSITION);
282+ }
283+
284+ /**
285+ * RuleBasedCollator constructor. This takes the table rules and builds
286+ * a collation table out of them. Please see RuleBasedCollator class
287+ * description for more details on the collation rule syntax.
288+ * @see java.util.Locale
289+ * @param rules the collation rules to build the collation table from.
290+ * @param decomp the decomposition strength used to build the
291+ * collation table and to perform comparisons.
292+ * @exception ParseException A format exception
293+ * will be thrown if the build process of the rules fails. For
294+ * example, build rule "a < ? < d" will cause the constructor to
295+ * throw the ParseException because the '?' is not quoted.
296+ */
297+ RuleBasedCollator(String rules, int decomp) throws ParseException {
298+ setStrength(Collator.TERTIARY);
299+ setDecomposition(decomp);
300+ tables = new RBCollationTables(rules, decomp);
301+ }
302+
303+ /**
304+ * "Copy constructor." Used in clone() for performance.
305+ */
306+ private RuleBasedCollator(RuleBasedCollator that) {
307+ setStrength(that.getStrength());
308+ setDecomposition(that.getDecomposition());
309+ tables = that.tables;
310+ }
311+
312+ /**
313+ * Gets the table-based rules for the collation object.
314+ * @return returns the collation rules that the table collation object
315+ * was created from.
316+ */
317+ public String getRules()
318+ {
319+ return tables.getRules();
320+ }
321+
322+ /**
323+ * Return a CollationElementIterator for the given String.
324+ * @see java.text.CollationElementIterator
325+ */
326+ public CollationElementIterator getCollationElementIterator(String source) {
327+ return new CollationElementIterator( source, this );
328+ }
329+
330+ /**
331+ * Return a CollationElementIterator for the given String.
332+ * @see java.text.CollationElementIterator
333+ * @since 1.2
334+ */
335+ public CollationElementIterator getCollationElementIterator(
336+ CharacterIterator source) {
337+ return new CollationElementIterator( source, this );
338+ }
339+
340+ /**
341+ * Compares the character data stored in two different strings based on the
342+ * collation rules. Returns information about whether a string is less
343+ * than, greater than or equal to another string in a language.
344+ * This can be overriden in a subclass.
345+ *
346+ * @exception NullPointerException if <code>source</code> or <code>target</code> is null.
347+ */
348+ public synchronized int compare(String source, String target)
349+ {
350+ if (source == null || target == null) {
351+ throw new NullPointerException();
352+ }
353+
354+ // The basic algorithm here is that we use CollationElementIterators
355+ // to step through both the source and target strings. We compare each
356+ // collation element in the source string against the corresponding one
357+ // in the target, checking for differences.
358+ //
359+ // If a difference is found, we set <result> to LESS or GREATER to
360+ // indicate whether the source string is less or greater than the target.
361+ //
362+ // However, it's not that simple. If we find a tertiary difference
363+ // (e.g. 'A' vs. 'a') near the beginning of a string, it can be
364+ // overridden by a primary difference (e.g. "A" vs. "B") later in
365+ // the string. For example, "AA" < "aB", even though 'A' > 'a'.
366+ //
367+ // To keep track of this, we use strengthResult to keep track of the
368+ // strength of the most significant difference that has been found
369+ // so far. When we find a difference whose strength is greater than
370+ // strengthResult, it overrides the last difference (if any) that
371+ // was found.
372+
373+ int result = Collator.EQUAL;
374+
375+ if (sourceCursor == null) {
376+ sourceCursor = getCollationElementIterator(source);
377+ } else {
378+ sourceCursor.setText(source);
379+ }
380+ if (targetCursor == null) {
381+ targetCursor = getCollationElementIterator(target);
382+ } else {
383+ targetCursor.setText(target);
384+ }
385+
386+ int sOrder = 0, tOrder = 0;
387+
388+ boolean initialCheckSecTer = getStrength() >= Collator.SECONDARY;
389+ boolean checkSecTer = initialCheckSecTer;
390+ boolean checkTertiary = getStrength() >= Collator.TERTIARY;
391+
392+ boolean gets = true, gett = true;
393+
394+ while(true) {
395+ // Get the next collation element in each of the strings, unless
396+ // we've been requested to skip it.
397+ if (gets) sOrder = sourceCursor.next(); else gets = true;
398+ if (gett) tOrder = targetCursor.next(); else gett = true;
399+
400+ // If we've hit the end of one of the strings, jump out of the loop
401+ if ((sOrder == CollationElementIterator.NULLORDER)||
402+ (tOrder == CollationElementIterator.NULLORDER))
403+ break;
404+
405+ int pSOrder = CollationElementIterator.primaryOrder(sOrder);
406+ int pTOrder = CollationElementIterator.primaryOrder(tOrder);
407+
408+ // If there's no difference at this position, we can skip it
409+ if (sOrder == tOrder) {
410+ if (tables.isFrenchSec() && pSOrder != 0) {
411+ if (!checkSecTer) {
412+ // in french, a secondary difference more to the right is stronger,
413+ // so accents have to be checked with each base element
414+ checkSecTer = initialCheckSecTer;
415+ // but tertiary differences are less important than the first
416+ // secondary difference, so checking tertiary remains disabled
417+ checkTertiary = false;
418+ }
419+ }
420+ continue;
421+ }
422+
423+ // Compare primary differences first.
424+ if ( pSOrder != pTOrder )
425+ {
426+ if (sOrder == 0) {
427+ // The entire source element is ignorable.
428+ // Skip to the next source element, but don't fetch another target element.
429+ gett = false;
430+ continue;
431+ }
432+ if (tOrder == 0) {
433+ gets = false;
434+ continue;
435+ }
436+
437+ // The source and target elements aren't ignorable, but it's still possible
438+ // for the primary component of one of the elements to be ignorable....
439+
440+ if (pSOrder == 0) // primary order in source is ignorable
441+ {
442+ // The source's primary is ignorable, but the target's isn't. We treat ignorables
443+ // as a secondary difference, so remember that we found one.
444+ if (checkSecTer) {
445+ result = Collator.GREATER; // (strength is SECONDARY)
446+ checkSecTer = false;
447+ }
448+ // Skip to the next source element, but don't fetch another target element.
449+ gett = false;
450+ }
451+ else if (pTOrder == 0)
452+ {
453+ // record differences - see the comment above.
454+ if (checkSecTer) {
455+ result = Collator.LESS; // (strength is SECONDARY)
456+ checkSecTer = false;
457+ }
458+ // Skip to the next source element, but don't fetch another target element.
459+ gets = false;
460+ } else {
461+ // Neither of the orders is ignorable, and we already know that the primary
462+ // orders are different because of the (pSOrder != pTOrder) test above.
463+ // Record the difference and stop the comparison.
464+ if (pSOrder < pTOrder) {
465+ return Collator.LESS; // (strength is PRIMARY)
466+ } else {
467+ return Collator.GREATER; // (strength is PRIMARY)
468+ }
469+ }
470+ } else { // else of if ( pSOrder != pTOrder )
471+ // primary order is the same, but complete order is different. So there
472+ // are no base elements at this point, only ignorables (Since the strings are
473+ // normalized)
474+
475+ if (checkSecTer) {
476+ // a secondary or tertiary difference may still matter
477+ short secSOrder = CollationElementIterator.secondaryOrder(sOrder);
478+ short secTOrder = CollationElementIterator.secondaryOrder(tOrder);
479+ if (secSOrder != secTOrder) {
480+ // there is a secondary difference
481+ result = (secSOrder < secTOrder) ? Collator.LESS : Collator.GREATER;
482+ // (strength is SECONDARY)
483+ checkSecTer = false;
484+ // (even in french, only the first secondary difference within
485+ // a base character matters)
486+ } else {
487+ if (checkTertiary) {
488+ // a tertiary difference may still matter
489+ short terSOrder = CollationElementIterator.tertiaryOrder(sOrder);
490+ short terTOrder = CollationElementIterator.tertiaryOrder(tOrder);
491+ if (terSOrder != terTOrder) {
492+ // there is a tertiary difference
493+ result = (terSOrder < terTOrder) ? Collator.LESS : Collator.GREATER;
494+ // (strength is TERTIARY)
495+ checkTertiary = false;
496+ }
497+ }
498+ }
499+ } // if (checkSecTer)
500+
501+ } // if ( pSOrder != pTOrder )
502+ } // while()
503+
504+ if (sOrder != CollationElementIterator.NULLORDER) {
505+ // (tOrder must be CollationElementIterator::NULLORDER,
506+ // since this point is only reached when sOrder or tOrder is NULLORDER.)
507+ // The source string has more elements, but the target string hasn't.
508+ do {
509+ if (CollationElementIterator.primaryOrder(sOrder) != 0) {
510+ // We found an additional non-ignorable base character in the source string.
511+ // This is a primary difference, so the source is greater
512+ return Collator.GREATER; // (strength is PRIMARY)
513+ }
514+ else if (CollationElementIterator.secondaryOrder(sOrder) != 0) {
515+ // Additional secondary elements mean the source string is greater
516+ if (checkSecTer) {
517+ result = Collator.GREATER; // (strength is SECONDARY)
518+ checkSecTer = false;
519+ }
520+ }
521+ } while ((sOrder = sourceCursor.next()) != CollationElementIterator.NULLORDER);
522+ }
523+ else if (tOrder != CollationElementIterator.NULLORDER) {
524+ // The target string has more elements, but the source string hasn't.
525+ do {
526+ if (CollationElementIterator.primaryOrder(tOrder) != 0)
527+ // We found an additional non-ignorable base character in the target string.
528+ // This is a primary difference, so the source is less
529+ return Collator.LESS; // (strength is PRIMARY)
530+ else if (CollationElementIterator.secondaryOrder(tOrder) != 0) {
531+ // Additional secondary elements in the target mean the source string is less
532+ if (checkSecTer) {
533+ result = Collator.LESS; // (strength is SECONDARY)
534+ checkSecTer = false;
535+ }
536+ }
537+ } while ((tOrder = targetCursor.next()) != CollationElementIterator.NULLORDER);
538+ }
539+
540+ // For IDENTICAL comparisons, we use a bitwise character comparison
541+ // as a tiebreaker if all else is equal
542+ if (result == 0 && getStrength() == IDENTICAL) {
543+ int mode = getDecomposition();
544+ Normalizer.Form form;
545+ if (mode == CANONICAL_DECOMPOSITION) {
546+ form = Normalizer.Form.NFD;
547+ } else if (mode == FULL_DECOMPOSITION) {
548+ form = Normalizer.Form.NFKD;
549+ } else {
550+ return source.compareTo(target);
551+ }
552+
553+ String sourceDecomposition = Normalizer.normalize(source, form);
554+ String targetDecomposition = Normalizer.normalize(target, form);
555+ return sourceDecomposition.compareTo(targetDecomposition);
556+ }
557+ return result;
558+ }
559+
560+ /**
561+ * Transforms the string into a series of characters that can be compared
562+ * with CollationKey.compareTo. This overrides java.text.Collator.getCollationKey.
563+ * It can be overriden in a subclass.
564+ */
565+ public synchronized CollationKey getCollationKey(String source)
566+ {
567+ //
568+ // The basic algorithm here is to find all of the collation elements for each
569+ // character in the source string, convert them to a char representation,
570+ // and put them into the collation key. But it's trickier than that.
571+ // Each collation element in a string has three components: primary (A vs B),
572+ // secondary (A vs A-acute), and tertiary (A' vs a); and a primary difference
573+ // at the end of a string takes precedence over a secondary or tertiary
574+ // difference earlier in the string.
575+ //
576+ // To account for this, we put all of the primary orders at the beginning of the
577+ // string, followed by the secondary and tertiary orders, separated by nulls.
578+ //
579+ // Here's a hypothetical example, with the collation element represented as
580+ // a three-digit number, one digit for primary, one for secondary, etc.
581+ //
582+ // String: A a B \u00e9 <--(e-acute)
583+ // Collation Elements: 101 100 201 510
584+ //
585+ // Collation Key: 1125<null>0001<null>1010
586+ //
587+ // To make things even trickier, secondary differences (accent marks) are compared
588+ // starting at the *end* of the string in languages with French secondary ordering.
589+ // But when comparing the accent marks on a single base character, they are compared
590+ // from the beginning. To handle this, we reverse all of the accents that belong
591+ // to each base character, then we reverse the entire string of secondary orderings
592+ // at the end. Taking the same example above, a French collator might return
593+ // this instead:
594+ //
595+ // Collation Key: 1125<null>1000<null>1010
596+ //
597+ if (source == null)
598+ return null;
599+
600+ if (primResult == null) {
601+ primResult = new StringBuffer();
602+ secResult = new StringBuffer();
603+ terResult = new StringBuffer();
604+ } else {
605+ primResult.setLength(0);
606+ secResult.setLength(0);
607+ terResult.setLength(0);
608+ }
609+ int order = 0;
610+ boolean compareSec = (getStrength() >= Collator.SECONDARY);
611+ boolean compareTer = (getStrength() >= Collator.TERTIARY);
612+ int secOrder = CollationElementIterator.NULLORDER;
613+ int terOrder = CollationElementIterator.NULLORDER;
614+ int preSecIgnore = 0;
615+
616+ if (sourceCursor == null) {
617+ sourceCursor = getCollationElementIterator(source);
618+ } else {
619+ sourceCursor.setText(source);
620+ }
621+
622+ // walk through each character
623+ while ((order = sourceCursor.next()) !=
624+ CollationElementIterator.NULLORDER)
625+ {
626+ secOrder = CollationElementIterator.secondaryOrder(order);
627+ terOrder = CollationElementIterator.tertiaryOrder(order);
628+ if (!CollationElementIterator.isIgnorable(order))
629+ {
630+ primResult.append((char) (CollationElementIterator.primaryOrder(order)
631+ + COLLATIONKEYOFFSET));
632+
633+ if (compareSec) {
634+ //
635+ // accumulate all of the ignorable/secondary characters attached
636+ // to a given base character
637+ //
638+ if (tables.isFrenchSec() && preSecIgnore < secResult.length()) {
639+ //
640+ // We're doing reversed secondary ordering and we've hit a base
641+ // (non-ignorable) character. Reverse any secondary orderings
642+ // that applied to the last base character. (see block comment above.)
643+ //
644+ RBCollationTables.reverse(secResult, preSecIgnore, secResult.length());
645+ }
646+ // Remember where we are in the secondary orderings - this is how far
647+ // back to go if we need to reverse them later.
648+ secResult.append((char)(secOrder+ COLLATIONKEYOFFSET));
649+ preSecIgnore = secResult.length();
650+ }
651+ if (compareTer) {
652+ terResult.append((char)(terOrder+ COLLATIONKEYOFFSET));
653+ }
654+ }
655+ else
656+ {
657+ if (compareSec && secOrder != 0)
658+ secResult.append((char)
659+ (secOrder + tables.getMaxSecOrder() + COLLATIONKEYOFFSET));
660+ if (compareTer && terOrder != 0)
661+ terResult.append((char)
662+ (terOrder + tables.getMaxTerOrder() + COLLATIONKEYOFFSET));
663+ }
664+ }
665+ if (tables.isFrenchSec())
666+ {
667+ if (preSecIgnore < secResult.length()) {
668+ // If we've accumlated any secondary characters after the last base character,
669+ // reverse them.
670+ RBCollationTables.reverse(secResult, preSecIgnore, secResult.length());
671+ }
672+ // And now reverse the entire secResult to get French secondary ordering.
673+ RBCollationTables.reverse(secResult, 0, secResult.length());
674+ }
675+ primResult.append((char)0);
676+ secResult.append((char)0);
677+ secResult.append(terResult.toString());
678+ primResult.append(secResult.toString());
679+
680+ if (getStrength() == IDENTICAL) {
681+ primResult.append((char)0);
682+ int mode = getDecomposition();
683+ if (mode == CANONICAL_DECOMPOSITION) {
684+ primResult.append(Normalizer.normalize(source, Normalizer.Form.NFD));
685+ } else if (mode == FULL_DECOMPOSITION) {
686+ primResult.append(Normalizer.normalize(source, Normalizer.Form.NFKD));
687+ } else {
688+ primResult.append(source);
689+ }
690+ }
691+ return new RuleBasedCollationKey(source, primResult.toString());
692+ }
693+
694+ /**
695+ * Standard override; no change in semantics.
696+ */
697+ public Object clone() {
698+ // if we know we're not actually a subclass of RuleBasedCollator
699+ // (this class really should have been made final), bypass
700+ // Object.clone() and use our "copy constructor". This is faster.
701+ if (getClass() == RuleBasedCollator.class) {
702+ return new RuleBasedCollator(this);
703+ }
704+ else {
705+ RuleBasedCollator result = (RuleBasedCollator) super.clone();
706+ result.primResult = null;
707+ result.secResult = null;
708+ result.terResult = null;
709+ result.sourceCursor = null;
710+ result.targetCursor = null;
711+ return result;
712+ }
713+ }
714+
715+ /**
716+ * Compares the equality of two collation objects.
717+ * @param obj the table-based collation object to be compared with this.
718+ * @return true if the current table-based collation object is the same
719+ * as the table-based collation object obj; false otherwise.
720+ */
721+ public boolean equals(Object obj) {
722+ if (obj == null) return false;
723+ if (!super.equals(obj)) return false; // super does class check
724+ RuleBasedCollator other = (RuleBasedCollator) obj;
725+ // all other non-transient information is also contained in rules.
726+ return (getRules().equals(other.getRules()));
727+ }
728+
729+ /**
730+ * Generates the hash code for the table-based collation object
731+ */
732+ public int hashCode() {
733+ return getRules().hashCode();
734+ }
735+
736+ /**
737+ * Allows CollationElementIterator access to the tables object
738+ */
739+ RBCollationTables getTables() {
740+ return tables;
741+ }
742+
743+ // ==============================================================
744+ // private
745+ // ==============================================================
746+
747+ final static int CHARINDEX = 0x70000000; // need look up in .commit()
748+ final static int EXPANDCHARINDEX = 0x7E000000; // Expand index follows
749+ final static int CONTRACTCHARINDEX = 0x7F000000; // contract indexes follow
750+ final static int UNMAPPED = 0xFFFFFFFF;
751+
752+ private final static int COLLATIONKEYOFFSET = 1;
753+
754+ private RBCollationTables tables = null;
755+
756+ // Internal objects that are cached across calls so that they don't have to
757+ // be created/destroyed on every call to compare() and getCollationKey()
758+ private StringBuffer primResult = null;
759+ private StringBuffer secResult = null;
760+ private StringBuffer terResult = null;
761+ private CollationElementIterator sourceCursor = null;
762+ private CollationElementIterator targetCursor = null;
763+}