-
RuleBasedCollator
-
RuleBasedCollator(String): void
-
RuleBasedCollator(String, int): void
-
RuleBasedCollator(RuleBasedCollator): void
-
getRules(): String
-
getCollationElementIterator(String): CollationElementIterator
-
getCollationElementIterator(CharacterIterator): CollationElementIterator
-
compare(String, String): int
-
getCollationKey(String): CollationKey
-
clone(): Object
-
equals(Object): boolean
-
hashCode(): int
-
getTables(): RBCollationTables
-
CHARINDEX: int
-
EXPANDCHARINDEX: int
-
CONTRACTCHARINDEX: int
-
UNMAPPED: int
-
COLLATIONKEYOFFSET: int
-
tables: RBCollationTables
-
primResult: StringBuffer
-
secResult: StringBuffer
-
terResult: StringBuffer
-
sourceCursor: CollationElementIterator
-
targetCursor: CollationElementIterator
-
/*
* Copyright (c) 1997, 2020, 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 RuleBasedCollator class is a concrete subclass of Collator that provides a simple, data-driven, table collator. With this class you can create a customized table-based Collator. RuleBasedCollator maps characters to sort keys. RuleBasedCollator has the following restrictions for efficiency (other subclasses may be used for more complex languages) :
- If a special collation rule controlled by a <modifier> is
specified it applies to the whole collator object.
- All non-mentioned characters are at the end of the
collation order.
The collation table is composed of a list of collation rules, where each
rule is of one of three forms:
<modifier>
<relation> <text-argument>
<reset> <text-argument>
The definitions of the rule elements is as follows:
- Text-Argument: 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.
b c is treated as bc. - Modifier: There are currently two modifiers that
turn on special collation rules.
- '@' : Turns on backwards sorting of accents (secondary
differences), as in French.
- '!' : 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.
'@' : Indicates that accents are sorted backwards, as in French.
- Relation: The relations are the following:
- '<' : Greater, as a letter difference (primary)
- ';' : Greater, as an accent difference (secondary)
- ',' : Greater, as a case difference (tertiary)
- '=' : Equal
- Reset: 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.
'&' : Indicates that the next rule follows the position to where
the reset text-argument would be sorted.
This sounds more complicated than it is in practice. For example, the
following are equivalent ways of expressing the same thing:
a < b < c
a < b & b < c
a < c & a < b
Notice that the order is important, as the subsequent item goes immediately
after the text-argument. The following are not equivalent:
a < b & a < c
a < c & a < b
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.]
Ignorable Characters
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.
Normalization and Accents
RuleBasedCollator 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.
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.
Errors
The following are errors:
- A text-argument contains unquoted punctuation symbols
(e.g. "a < b-c < d").
- A relation or reset character not followed by a text-argument
(e.g. "a < ,b").
- 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")
If you produce one of these errors, a RuleBasedCollator throws a ParseException. Examples
Simple: "< a < b < c < d"
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"
To create a RuleBasedCollator object with specialized rules tailored to your needs, you construct the RuleBasedCollator with the rules contained in a String object. For example:
String simple = "< a< b< c< d";
RuleBasedCollator mySimple = new RuleBasedCollator(simple);
Or:
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);
A new collation rules string can be created by concatenating rules strings. For example, the rules returned by getRules() could be concatenated to combine multiple RuleBasedCollators.
The following example demonstrates how to change the order of
non-spacing accents,
// 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);
Author: Helena Shih, Laura Werner, Richard Gillam See Also: Since: 1.1
/**
* The {@code RuleBasedCollator} class is a concrete subclass of
* {@code Collator} that provides a simple, data-driven, table
* collator. With this class you can create a customized table-based
* {@code Collator}. {@code RuleBasedCollator} maps
* characters to sort keys.
*
* <p>
* {@code RuleBasedCollator} 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} is treated as {@code bc}.
* <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} 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} throws
* a {@code ParseException}.
*
* <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} object with specialized
* rules tailored to your needs, you construct the {@code RuleBasedCollator}
* with the rules contained in a {@code String} 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}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.
Params: - rules – the collation rules to build the collation table from.
Throws: - 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.
See Also: - Locale
/**
* 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.
* @throws 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.
Params: - rules – the collation rules to build the collation table from.
- decomp – the decomposition strength used to build the
collation table and to perform comparisons.
Throws: - 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.
See Also: - Locale
/**
* 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.
* @throws 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.
/**
* "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.
Returns: returns the collation rules that the table collation object
was created from.
/**
* 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.
Params: - source – the string to be collated
See Also: Returns: a CollationElementIterator object
/**
* 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.
Params: - source – the character iterator to be collated
See Also: Returns: a CollationElementIterator object Since: 1.2
/**
* 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 overridden in a subclass.
Throws: - NullPointerException – if
source or target is null.
/**
* 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 overridden in a subclass.
*
* @throws NullPointerException if {@code source} or {@code target} 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 overridden in a subclass.
/**
* Transforms the string into a series of characters that can be compared
* with CollationKey.compareTo. This overrides java.text.Collator.getCollationKey.
* It can be overridden 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.
/**
* 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.
Params: - obj – the table-based collation object to be compared with this.
Returns: true if the current table-based collation object is the same
as the table-based collation object obj; false otherwise.
/**
* 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
/**
* Generates the hash code for the table-based collation object
*/
public int hashCode() {
return getRules().hashCode();
}
Allows CollationElementIterator access to the tables object
/**
* 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;
}