--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/text/RuleBasedCollator.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,770 @@
+/*
+ * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+/*
+ * (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
+ * (C) Copyright IBM Corp. 1996-1998 - All Rights Reserved
+ *
+ * The original version of this source code and documentation is copyrighted
+ * and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
+ * materials are provided under terms of a License Agreement between Taligent
+ * and Sun. This technology is protected by multiple US and International
+ * patents. This notice and attribution to Taligent may not be removed.
+ * Taligent is a registered trademark of Taligent, Inc.
+ *
+ */
+
+package java.text;
+
+import java.text.Normalizer;
+import java.util.Vector;
+import java.util.Locale;
+
+/**
+ * The <code>RuleBasedCollator</code> class is a concrete subclass of
+ * <code>Collator</code> that provides a simple, data-driven, table
+ * collator. With this class you can create a customized table-based
+ * <code>Collator</code>. <code>RuleBasedCollator</code> maps
+ * characters to sort keys.
+ *
+ * <p>
+ * <code>RuleBasedCollator</code> has the following restrictions
+ * for efficiency (other subclasses may be used for more complex languages) :
+ * <ol>
+ * <li>If a special collation rule controlled by a <modifier> is
+ specified it applies to the whole collator object.
+ * <li>All non-mentioned characters are at the end of the
+ * collation order.
+ * </ol>
+ *
+ * <p>
+ * The collation table is composed of a list of collation rules, where each
+ * rule is of one of three forms:
+ * <pre>
+ * <modifier>
+ * <relation> <text-argument>
+ * <reset> <text-argument>
+ * </pre>
+ * The definitions of the rule elements is as follows:
+ * <UL>
+ * <LI><strong>Text-Argument</strong>: A text-argument is any sequence of
+ * characters, excluding special characters (that is, common
+ * whitespace characters [0009-000D, 0020] and rule syntax characters
+ * [0021-002F, 003A-0040, 005B-0060, 007B-007E]). If those
+ * characters are desired, you can put them in single quotes
+ * (e.g. ampersand => '&'). Note that unquoted white space characters
+ * are ignored; e.g. <code>b c</code> is treated as <code>bc</code>.
+ * <LI><strong>Modifier</strong>: There are currently two modifiers that
+ * turn on special collation rules.
+ * <UL>
+ * <LI>'@' : Turns on backwards sorting of accents (secondary
+ * differences), as in French.
+ * <LI>'!' : Turns on Thai/Lao vowel-consonant swapping. If this
+ * rule is in force when a Thai vowel of the range
+ * \U0E40-\U0E44 precedes a Thai consonant of the range
+ * \U0E01-\U0E2E OR a Lao vowel of the range \U0EC0-\U0EC4
+ * precedes a Lao consonant of the range \U0E81-\U0EAE then
+ * the vowel is placed after the consonant for collation
+ * purposes.
+ * </UL>
+ * <p>'@' : Indicates that accents are sorted backwards, as in French.
+ * <LI><strong>Relation</strong>: The relations are the following:
+ * <UL>
+ * <LI>'<' : Greater, as a letter difference (primary)
+ * <LI>';' : Greater, as an accent difference (secondary)
+ * <LI>',' : Greater, as a case difference (tertiary)
+ * <LI>'=' : Equal
+ * </UL>
+ * <LI><strong>Reset</strong>: There is a single reset
+ * which is used primarily for contractions and expansions, but which
+ * can also be used to add a modification at the end of a set of rules.
+ * <p>'&' : Indicates that the next rule follows the position to where
+ * the reset text-argument would be sorted.
+ * </UL>
+ *
+ * <p>
+ * This sounds more complicated than it is in practice. For example, the
+ * following are equivalent ways of expressing the same thing:
+ * <blockquote>
+ * <pre>
+ * a < b < c
+ * a < b & b < c
+ * a < c & a < b
+ * </pre>
+ * </blockquote>
+ * Notice that the order is important, as the subsequent item goes immediately
+ * after the text-argument. The following are not equivalent:
+ * <blockquote>
+ * <pre>
+ * a < b & a < c
+ * a < c & a < b
+ * </pre>
+ * </blockquote>
+ * Either the text-argument must already be present in the sequence, or some
+ * initial substring of the text-argument must be present. (e.g. "a < b & ae <
+ * e" is valid since "a" is present in the sequence before "ae" is reset). In
+ * this latter case, "ae" is not entered and treated as a single character;
+ * instead, "e" is sorted as if it were expanded to two characters: "a"
+ * followed by an "e". This difference appears in natural languages: in
+ * traditional Spanish "ch" is treated as though it contracts to a single
+ * character (expressed as "c < ch < d"), while in traditional German
+ * a-umlaut is treated as though it expanded to two characters
+ * (expressed as "a,A < b,B ... &ae;\u00e3&AE;\u00c3").
+ * [\u00e3 and \u00c3 are, of course, the escape sequences for a-umlaut.]
+ * <p>
+ * <strong>Ignorable Characters</strong>
+ * <p>
+ * For ignorable characters, the first rule must start with a relation (the
+ * examples we have used above are really fragments; "a < b" really should be
+ * "< a < b"). If, however, the first relation is not "<", then all the all
+ * text-arguments up to the first "<" are ignorable. For example, ", - < a < b"
+ * makes "-" an ignorable character, as we saw earlier in the word
+ * "black-birds". In the samples for different languages, you see that most
+ * accents are ignorable.
+ *
+ * <p><strong>Normalization and Accents</strong>
+ * <p>
+ * <code>RuleBasedCollator</code> automatically processes its rule table to
+ * include both pre-composed and combining-character versions of
+ * accented characters. Even if the provided rule string contains only
+ * base characters and separate combining accent characters, the pre-composed
+ * accented characters matching all canonical combinations of characters from
+ * the rule string will be entered in the table.
+ * <p>
+ * This allows you to use a RuleBasedCollator to compare accented strings
+ * even when the collator is set to NO_DECOMPOSITION. There are two caveats,
+ * however. First, if the strings to be collated contain combining
+ * sequences that may not be in canonical order, you should set the collator to
+ * CANONICAL_DECOMPOSITION or FULL_DECOMPOSITION to enable sorting of
+ * combining sequences. Second, if the strings contain characters with
+ * compatibility decompositions (such as full-width and half-width forms),
+ * you must use FULL_DECOMPOSITION, since the rule tables only include
+ * canonical mappings.
+ *
+ * <p><strong>Errors</strong>
+ * <p>
+ * The following are errors:
+ * <UL>
+ * <LI>A text-argument contains unquoted punctuation symbols
+ * (e.g. "a < b-c < d").
+ * <LI>A relation or reset character not followed by a text-argument
+ * (e.g. "a < ,b").
+ * <LI>A reset where the text-argument (or an initial substring of the
+ * text-argument) is not already in the sequence.
+ * (e.g. "a < b & e < f")
+ * </UL>
+ * If you produce one of these errors, a <code>RuleBasedCollator</code> throws
+ * a <code>ParseException</code>.
+ *
+ * <p><strong>Examples</strong>
+ * <p>Simple: "< a < b < c < d"
+ * <p>Norwegian: "< a, A < b, B < c, C < d, D < e, E < f, F
+ * < g, G < h, H < i, I < j, J < k, K < l, L
+ * < m, M < n, N < o, O < p, P < q, Q < r, R
+ * < s, S < t, T < u, U < v, V < w, W < x, X
+ * < y, Y < z, Z
+ * < \u00E6, \u00C6
+ * < \u00F8, \u00D8
+ * < \u00E5 = a\u030A, \u00C5 = A\u030A;
+ * aa, AA"
+ *
+ * <p>
+ * To create a <code>RuleBasedCollator</code> object with specialized
+ * rules tailored to your needs, you construct the <code>RuleBasedCollator</code>
+ * with the rules contained in a <code>String</code> object. For example:
+ * <blockquote>
+ * <pre>
+ * String simple = "< a< b< c< d";
+ * RuleBasedCollator mySimple = new RuleBasedCollator(simple);
+ * </pre>
+ * </blockquote>
+ * Or:
+ * <blockquote>
+ * <pre>
+ * String Norwegian = "< a, A < b, B < c, C < d, D < e, E < f, F < g, G < h, H < i, I" +
+ * "< j, J < k, K < l, L < m, M < n, N < o, O < p, P < q, Q < r, R" +
+ * "< s, S < t, T < u, U < v, V < w, W < x, X < y, Y < z, Z" +
+ * "< \u00E6, \u00C6" + // Latin letter ae & AE
+ * "< \u00F8, \u00D8" + // Latin letter o & O with stroke
+ * "< \u00E5 = a\u030A," + // Latin letter a with ring above
+ * " \u00C5 = A\u030A;" + // Latin letter A with ring above
+ * " aa, AA";
+ * RuleBasedCollator myNorwegian = new RuleBasedCollator(Norwegian);
+ * </pre>
+ * </blockquote>
+ *
+ * <p>
+ * A new collation rules string can be created by concatenating rules
+ * strings. For example, the rules returned by {@link #getRules()} could
+ * be concatenated to combine multiple <code>RuleBasedCollator</code>s.
+ *
+ * <p>
+ * The following example demonstrates how to change the order of
+ * non-spacing accents,
+ * <blockquote>
+ * <pre>
+ * // old rule
+ * String oldRules = "=\u0301;\u0300;\u0302;\u0308" // main accents
+ * + ";\u0327;\u0303;\u0304;\u0305" // main accents
+ * + ";\u0306;\u0307;\u0309;\u030A" // main accents
+ * + ";\u030B;\u030C;\u030D;\u030E" // main accents
+ * + ";\u030F;\u0310;\u0311;\u0312" // main accents
+ * + "< a , A ; ae, AE ; \u00e6 , \u00c6"
+ * + "< b , B < c, C < e, E & C < d, D";
+ * // change the order of accent characters
+ * String addOn = "& \u0300 ; \u0308 ; \u0302";
+ * RuleBasedCollator myCollator = new RuleBasedCollator(oldRules + addOn);
+ * </pre>
+ * </blockquote>
+ *
+ * @see Collator
+ * @see CollationElementIterator
+ * @author Helena Shih, Laura Werner, Richard Gillam
+ * @since 1.1
+ */
+public class RuleBasedCollator extends Collator{
+ // IMPLEMENTATION NOTES: The implementation of the collation algorithm is
+ // divided across three classes: RuleBasedCollator, RBCollationTables, and
+ // CollationElementIterator. RuleBasedCollator contains the collator's
+ // transient state and includes the code that uses the other classes to
+ // implement comparison and sort-key building. RuleBasedCollator also
+ // contains the logic to handle French secondary accent sorting.
+ // A RuleBasedCollator has two CollationElementIterators. State doesn't
+ // need to be preserved in these objects between calls to compare() or
+ // getCollationKey(), but the objects persist anyway to avoid wasting extra
+ // creation time. compare() and getCollationKey() are synchronized to ensure
+ // thread safety with this scheme. The CollationElementIterator is responsible
+ // for generating collation elements from strings and returning one element at
+ // a time (sometimes there's a one-to-many or many-to-one mapping between
+ // characters and collation elements-- this class handles that).
+ // CollationElementIterator depends on RBCollationTables, which contains the
+ // collator's static state. RBCollationTables contains the actual data
+ // tables specifying the collation order of characters for a particular locale
+ // or use. It also contains the base logic that CollationElementIterator
+ // uses to map from characters to collation elements. A single RBCollationTables
+ // object is shared among all RuleBasedCollators for the same locale, and
+ // thus by all the CollationElementIterators they create.
+
+ /**
+ * RuleBasedCollator constructor. This takes the table rules and builds
+ * a collation table out of them. Please see RuleBasedCollator class
+ * description for more details on the collation rule syntax.
+ * @see java.util.Locale
+ * @param rules the collation rules to build the collation table from.
+ * @exception ParseException A format exception
+ * will be thrown if the build process of the rules fails. For
+ * example, build rule "a < ? < d" will cause the constructor to
+ * throw the ParseException because the '?' is not quoted.
+ */
+ public RuleBasedCollator(String rules) throws ParseException {
+ this(rules, Collator.CANONICAL_DECOMPOSITION);
+ }
+
+ /**
+ * RuleBasedCollator constructor. This takes the table rules and builds
+ * a collation table out of them. Please see RuleBasedCollator class
+ * description for more details on the collation rule syntax.
+ * @see java.util.Locale
+ * @param rules the collation rules to build the collation table from.
+ * @param decomp the decomposition strength used to build the
+ * collation table and to perform comparisons.
+ * @exception ParseException A format exception
+ * will be thrown if the build process of the rules fails. For
+ * example, build rule "a < ? < d" will cause the constructor to
+ * throw the ParseException because the '?' is not quoted.
+ */
+ RuleBasedCollator(String rules, int decomp) throws ParseException {
+ setStrength(Collator.TERTIARY);
+ setDecomposition(decomp);
+ tables = new RBCollationTables(rules, decomp);
+ }
+
+ /**
+ * "Copy constructor." Used in clone() for performance.
+ */
+ private RuleBasedCollator(RuleBasedCollator that) {
+ setStrength(that.getStrength());
+ setDecomposition(that.getDecomposition());
+ tables = that.tables;
+ }
+
+ /**
+ * Gets the table-based rules for the collation object.
+ * @return returns the collation rules that the table collation object
+ * was created from.
+ */
+ public String getRules()
+ {
+ return tables.getRules();
+ }
+
+ /**
+ * Returns a CollationElementIterator for the given String.
+ *
+ * @param source the string to be collated
+ * @return a {@code CollationElementIterator} object
+ * @see java.text.CollationElementIterator
+ */
+ public CollationElementIterator getCollationElementIterator(String source) {
+ return new CollationElementIterator( source, this );
+ }
+
+ /**
+ * Returns a CollationElementIterator for the given CharacterIterator.
+ *
+ * @param source the character iterator to be collated
+ * @return a {@code CollationElementIterator} object
+ * @see java.text.CollationElementIterator
+ * @since 1.2
+ */
+ public CollationElementIterator getCollationElementIterator(
+ CharacterIterator source) {
+ return new CollationElementIterator( source, this );
+ }
+
+ /**
+ * Compares the character data stored in two different strings based on the
+ * collation rules. Returns information about whether a string is less
+ * than, greater than or equal to another string in a language.
+ * This can be overriden in a subclass.
+ *
+ * @exception NullPointerException if <code>source</code> or <code>target</code> is null.
+ */
+ public synchronized int compare(String source, String target)
+ {
+ if (source == null || target == null) {
+ throw new NullPointerException();
+ }
+
+ // The basic algorithm here is that we use CollationElementIterators
+ // to step through both the source and target strings. We compare each
+ // collation element in the source string against the corresponding one
+ // in the target, checking for differences.
+ //
+ // If a difference is found, we set <result> to LESS or GREATER to
+ // indicate whether the source string is less or greater than the target.
+ //
+ // However, it's not that simple. If we find a tertiary difference
+ // (e.g. 'A' vs. 'a') near the beginning of a string, it can be
+ // overridden by a primary difference (e.g. "A" vs. "B") later in
+ // the string. For example, "AA" < "aB", even though 'A' > 'a'.
+ //
+ // To keep track of this, we use strengthResult to keep track of the
+ // strength of the most significant difference that has been found
+ // so far. When we find a difference whose strength is greater than
+ // strengthResult, it overrides the last difference (if any) that
+ // was found.
+
+ int result = Collator.EQUAL;
+
+ if (sourceCursor == null) {
+ sourceCursor = getCollationElementIterator(source);
+ } else {
+ sourceCursor.setText(source);
+ }
+ if (targetCursor == null) {
+ targetCursor = getCollationElementIterator(target);
+ } else {
+ targetCursor.setText(target);
+ }
+
+ int sOrder = 0, tOrder = 0;
+
+ boolean initialCheckSecTer = getStrength() >= Collator.SECONDARY;
+ boolean checkSecTer = initialCheckSecTer;
+ boolean checkTertiary = getStrength() >= Collator.TERTIARY;
+
+ boolean gets = true, gett = true;
+
+ while(true) {
+ // Get the next collation element in each of the strings, unless
+ // we've been requested to skip it.
+ if (gets) sOrder = sourceCursor.next(); else gets = true;
+ if (gett) tOrder = targetCursor.next(); else gett = true;
+
+ // If we've hit the end of one of the strings, jump out of the loop
+ if ((sOrder == CollationElementIterator.NULLORDER)||
+ (tOrder == CollationElementIterator.NULLORDER))
+ break;
+
+ int pSOrder = CollationElementIterator.primaryOrder(sOrder);
+ int pTOrder = CollationElementIterator.primaryOrder(tOrder);
+
+ // If there's no difference at this position, we can skip it
+ if (sOrder == tOrder) {
+ if (tables.isFrenchSec() && pSOrder != 0) {
+ if (!checkSecTer) {
+ // in french, a secondary difference more to the right is stronger,
+ // so accents have to be checked with each base element
+ checkSecTer = initialCheckSecTer;
+ // but tertiary differences are less important than the first
+ // secondary difference, so checking tertiary remains disabled
+ checkTertiary = false;
+ }
+ }
+ continue;
+ }
+
+ // Compare primary differences first.
+ if ( pSOrder != pTOrder )
+ {
+ if (sOrder == 0) {
+ // The entire source element is ignorable.
+ // Skip to the next source element, but don't fetch another target element.
+ gett = false;
+ continue;
+ }
+ if (tOrder == 0) {
+ gets = false;
+ continue;
+ }
+
+ // The source and target elements aren't ignorable, but it's still possible
+ // for the primary component of one of the elements to be ignorable....
+
+ if (pSOrder == 0) // primary order in source is ignorable
+ {
+ // The source's primary is ignorable, but the target's isn't. We treat ignorables
+ // as a secondary difference, so remember that we found one.
+ if (checkSecTer) {
+ result = Collator.GREATER; // (strength is SECONDARY)
+ checkSecTer = false;
+ }
+ // Skip to the next source element, but don't fetch another target element.
+ gett = false;
+ }
+ else if (pTOrder == 0)
+ {
+ // record differences - see the comment above.
+ if (checkSecTer) {
+ result = Collator.LESS; // (strength is SECONDARY)
+ checkSecTer = false;
+ }
+ // Skip to the next source element, but don't fetch another target element.
+ gets = false;
+ } else {
+ // Neither of the orders is ignorable, and we already know that the primary
+ // orders are different because of the (pSOrder != pTOrder) test above.
+ // Record the difference and stop the comparison.
+ if (pSOrder < pTOrder) {
+ return Collator.LESS; // (strength is PRIMARY)
+ } else {
+ return Collator.GREATER; // (strength is PRIMARY)
+ }
+ }
+ } else { // else of if ( pSOrder != pTOrder )
+ // primary order is the same, but complete order is different. So there
+ // are no base elements at this point, only ignorables (Since the strings are
+ // normalized)
+
+ if (checkSecTer) {
+ // a secondary or tertiary difference may still matter
+ short secSOrder = CollationElementIterator.secondaryOrder(sOrder);
+ short secTOrder = CollationElementIterator.secondaryOrder(tOrder);
+ if (secSOrder != secTOrder) {
+ // there is a secondary difference
+ result = (secSOrder < secTOrder) ? Collator.LESS : Collator.GREATER;
+ // (strength is SECONDARY)
+ checkSecTer = false;
+ // (even in french, only the first secondary difference within
+ // a base character matters)
+ } else {
+ if (checkTertiary) {
+ // a tertiary difference may still matter
+ short terSOrder = CollationElementIterator.tertiaryOrder(sOrder);
+ short terTOrder = CollationElementIterator.tertiaryOrder(tOrder);
+ if (terSOrder != terTOrder) {
+ // there is a tertiary difference
+ result = (terSOrder < terTOrder) ? Collator.LESS : Collator.GREATER;
+ // (strength is TERTIARY)
+ checkTertiary = false;
+ }
+ }
+ }
+ } // if (checkSecTer)
+
+ } // if ( pSOrder != pTOrder )
+ } // while()
+
+ if (sOrder != CollationElementIterator.NULLORDER) {
+ // (tOrder must be CollationElementIterator::NULLORDER,
+ // since this point is only reached when sOrder or tOrder is NULLORDER.)
+ // The source string has more elements, but the target string hasn't.
+ do {
+ if (CollationElementIterator.primaryOrder(sOrder) != 0) {
+ // We found an additional non-ignorable base character in the source string.
+ // This is a primary difference, so the source is greater
+ return Collator.GREATER; // (strength is PRIMARY)
+ }
+ else if (CollationElementIterator.secondaryOrder(sOrder) != 0) {
+ // Additional secondary elements mean the source string is greater
+ if (checkSecTer) {
+ result = Collator.GREATER; // (strength is SECONDARY)
+ checkSecTer = false;
+ }
+ }
+ } while ((sOrder = sourceCursor.next()) != CollationElementIterator.NULLORDER);
+ }
+ else if (tOrder != CollationElementIterator.NULLORDER) {
+ // The target string has more elements, but the source string hasn't.
+ do {
+ if (CollationElementIterator.primaryOrder(tOrder) != 0)
+ // We found an additional non-ignorable base character in the target string.
+ // This is a primary difference, so the source is less
+ return Collator.LESS; // (strength is PRIMARY)
+ else if (CollationElementIterator.secondaryOrder(tOrder) != 0) {
+ // Additional secondary elements in the target mean the source string is less
+ if (checkSecTer) {
+ result = Collator.LESS; // (strength is SECONDARY)
+ checkSecTer = false;
+ }
+ }
+ } while ((tOrder = targetCursor.next()) != CollationElementIterator.NULLORDER);
+ }
+
+ // For IDENTICAL comparisons, we use a bitwise character comparison
+ // as a tiebreaker if all else is equal
+ if (result == 0 && getStrength() == IDENTICAL) {
+ int mode = getDecomposition();
+ Normalizer.Form form;
+ if (mode == CANONICAL_DECOMPOSITION) {
+ form = Normalizer.Form.NFD;
+ } else if (mode == FULL_DECOMPOSITION) {
+ form = Normalizer.Form.NFKD;
+ } else {
+ return source.compareTo(target);
+ }
+
+ String sourceDecomposition = Normalizer.normalize(source, form);
+ String targetDecomposition = Normalizer.normalize(target, form);
+ return sourceDecomposition.compareTo(targetDecomposition);
+ }
+ return result;
+ }
+
+ /**
+ * Transforms the string into a series of characters that can be compared
+ * with CollationKey.compareTo. This overrides java.text.Collator.getCollationKey.
+ * It can be overriden in a subclass.
+ */
+ public synchronized CollationKey getCollationKey(String source)
+ {
+ //
+ // The basic algorithm here is to find all of the collation elements for each
+ // character in the source string, convert them to a char representation,
+ // and put them into the collation key. But it's trickier than that.
+ // Each collation element in a string has three components: primary (A vs B),
+ // secondary (A vs A-acute), and tertiary (A' vs a); and a primary difference
+ // at the end of a string takes precedence over a secondary or tertiary
+ // difference earlier in the string.
+ //
+ // To account for this, we put all of the primary orders at the beginning of the
+ // string, followed by the secondary and tertiary orders, separated by nulls.
+ //
+ // Here's a hypothetical example, with the collation element represented as
+ // a three-digit number, one digit for primary, one for secondary, etc.
+ //
+ // String: A a B \u00e9 <--(e-acute)
+ // Collation Elements: 101 100 201 510
+ //
+ // Collation Key: 1125<null>0001<null>1010
+ //
+ // To make things even trickier, secondary differences (accent marks) are compared
+ // starting at the *end* of the string in languages with French secondary ordering.
+ // But when comparing the accent marks on a single base character, they are compared
+ // from the beginning. To handle this, we reverse all of the accents that belong
+ // to each base character, then we reverse the entire string of secondary orderings
+ // at the end. Taking the same example above, a French collator might return
+ // this instead:
+ //
+ // Collation Key: 1125<null>1000<null>1010
+ //
+ if (source == null)
+ return null;
+
+ if (primResult == null) {
+ primResult = new StringBuffer();
+ secResult = new StringBuffer();
+ terResult = new StringBuffer();
+ } else {
+ primResult.setLength(0);
+ secResult.setLength(0);
+ terResult.setLength(0);
+ }
+ int order = 0;
+ boolean compareSec = (getStrength() >= Collator.SECONDARY);
+ boolean compareTer = (getStrength() >= Collator.TERTIARY);
+ int secOrder = CollationElementIterator.NULLORDER;
+ int terOrder = CollationElementIterator.NULLORDER;
+ int preSecIgnore = 0;
+
+ if (sourceCursor == null) {
+ sourceCursor = getCollationElementIterator(source);
+ } else {
+ sourceCursor.setText(source);
+ }
+
+ // walk through each character
+ while ((order = sourceCursor.next()) !=
+ CollationElementIterator.NULLORDER)
+ {
+ secOrder = CollationElementIterator.secondaryOrder(order);
+ terOrder = CollationElementIterator.tertiaryOrder(order);
+ if (!CollationElementIterator.isIgnorable(order))
+ {
+ primResult.append((char) (CollationElementIterator.primaryOrder(order)
+ + COLLATIONKEYOFFSET));
+
+ if (compareSec) {
+ //
+ // accumulate all of the ignorable/secondary characters attached
+ // to a given base character
+ //
+ if (tables.isFrenchSec() && preSecIgnore < secResult.length()) {
+ //
+ // We're doing reversed secondary ordering and we've hit a base
+ // (non-ignorable) character. Reverse any secondary orderings
+ // that applied to the last base character. (see block comment above.)
+ //
+ RBCollationTables.reverse(secResult, preSecIgnore, secResult.length());
+ }
+ // Remember where we are in the secondary orderings - this is how far
+ // back to go if we need to reverse them later.
+ secResult.append((char)(secOrder+ COLLATIONKEYOFFSET));
+ preSecIgnore = secResult.length();
+ }
+ if (compareTer) {
+ terResult.append((char)(terOrder+ COLLATIONKEYOFFSET));
+ }
+ }
+ else
+ {
+ if (compareSec && secOrder != 0)
+ secResult.append((char)
+ (secOrder + tables.getMaxSecOrder() + COLLATIONKEYOFFSET));
+ if (compareTer && terOrder != 0)
+ terResult.append((char)
+ (terOrder + tables.getMaxTerOrder() + COLLATIONKEYOFFSET));
+ }
+ }
+ if (tables.isFrenchSec())
+ {
+ if (preSecIgnore < secResult.length()) {
+ // If we've accumulated any secondary characters after the last base character,
+ // reverse them.
+ RBCollationTables.reverse(secResult, preSecIgnore, secResult.length());
+ }
+ // And now reverse the entire secResult to get French secondary ordering.
+ RBCollationTables.reverse(secResult, 0, secResult.length());
+ }
+ primResult.append((char)0);
+ secResult.append((char)0);
+ secResult.append(terResult.toString());
+ primResult.append(secResult.toString());
+
+ if (getStrength() == IDENTICAL) {
+ primResult.append((char)0);
+ int mode = getDecomposition();
+ if (mode == CANONICAL_DECOMPOSITION) {
+ primResult.append(Normalizer.normalize(source, Normalizer.Form.NFD));
+ } else if (mode == FULL_DECOMPOSITION) {
+ primResult.append(Normalizer.normalize(source, Normalizer.Form.NFKD));
+ } else {
+ primResult.append(source);
+ }
+ }
+ return new RuleBasedCollationKey(source, primResult.toString());
+ }
+
+ /**
+ * Standard override; no change in semantics.
+ */
+ public Object clone() {
+ // if we know we're not actually a subclass of RuleBasedCollator
+ // (this class really should have been made final), bypass
+ // Object.clone() and use our "copy constructor". This is faster.
+ if (getClass() == RuleBasedCollator.class) {
+ return new RuleBasedCollator(this);
+ }
+ else {
+ RuleBasedCollator result = (RuleBasedCollator) super.clone();
+ result.primResult = null;
+ result.secResult = null;
+ result.terResult = null;
+ result.sourceCursor = null;
+ result.targetCursor = null;
+ return result;
+ }
+ }
+
+ /**
+ * Compares the equality of two collation objects.
+ * @param obj the table-based collation object to be compared with this.
+ * @return true if the current table-based collation object is the same
+ * as the table-based collation object obj; false otherwise.
+ */
+ public boolean equals(Object obj) {
+ if (obj == null) return false;
+ if (!super.equals(obj)) return false; // super does class check
+ RuleBasedCollator other = (RuleBasedCollator) obj;
+ // all other non-transient information is also contained in rules.
+ return (getRules().equals(other.getRules()));
+ }
+
+ /**
+ * Generates the hash code for the table-based collation object
+ */
+ public int hashCode() {
+ return getRules().hashCode();
+ }
+
+ /**
+ * Allows CollationElementIterator access to the tables object
+ */
+ RBCollationTables getTables() {
+ return tables;
+ }
+
+ // ==============================================================
+ // private
+ // ==============================================================
+
+ static final int CHARINDEX = 0x70000000; // need look up in .commit()
+ static final int EXPANDCHARINDEX = 0x7E000000; // Expand index follows
+ static final int CONTRACTCHARINDEX = 0x7F000000; // contract indexes follow
+ static final int UNMAPPED = 0xFFFFFFFF;
+
+ private static final int COLLATIONKEYOFFSET = 1;
+
+ private RBCollationTables tables = null;
+
+ // Internal objects that are cached across calls so that they don't have to
+ // be created/destroyed on every call to compare() and getCollationKey()
+ private StringBuffer primResult = null;
+ private StringBuffer secResult = null;
+ private StringBuffer terResult = null;
+ private CollationElementIterator sourceCursor = null;
+ private CollationElementIterator targetCursor = null;
+}