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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
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* 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
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*
* 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).
*
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* 2 along with this work; if not, write to the Free Software Foundation,
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*
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package sun.util.locale;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Locale;
import java.util.Locale.*;
import static java.util.Locale.FilteringMode.*;
import static java.util.Locale.LanguageRange.*;
import java.util.Map;
import java.util.Set;
import java.util.TreeSet;
import java.util.stream.Collectors;
/**
* Implementation for BCP47 Locale matching
*
*/
public final class LocaleMatcher {
public static List<Locale> filter(List<LanguageRange> priorityList,
Collection<Locale> locales,
FilteringMode mode) {
if (priorityList.isEmpty() || locales.isEmpty()) {
return new ArrayList<>(); // need to return a empty mutable List
}
// Create a list of language tags to be matched.
List<String> tags = new ArrayList<>();
for (Locale locale : locales) {
tags.add(locale.toLanguageTag());
}
// Filter language tags.
List<String> filteredTags = filterTags(priorityList, tags, mode);
// Create a list of matching locales.
List<Locale> filteredLocales = new ArrayList<>(filteredTags.size());
for (String tag : filteredTags) {
filteredLocales.add(Locale.forLanguageTag(tag));
}
return filteredLocales;
}
public static List<String> filterTags(List<LanguageRange> priorityList,
Collection<String> tags,
FilteringMode mode) {
if (priorityList.isEmpty() || tags.isEmpty()) {
return new ArrayList<>(); // need to return a empty mutable List
}
ArrayList<LanguageRange> list;
if (mode == EXTENDED_FILTERING) {
return filterExtended(priorityList, tags);
} else {
list = new ArrayList<>();
for (LanguageRange lr : priorityList) {
String range = lr.getRange();
if (range.startsWith("*-")
|| range.indexOf("-*") != -1) { // Extended range
if (mode == AUTOSELECT_FILTERING) {
return filterExtended(priorityList, tags);
} else if (mode == MAP_EXTENDED_RANGES) {
if (range.charAt(0) == '*') {
range = "*";
} else {
range = range.replaceAll("-[*]", "");
}
list.add(new LanguageRange(range, lr.getWeight()));
} else if (mode == REJECT_EXTENDED_RANGES) {
throw new IllegalArgumentException("An extended range \""
+ range
+ "\" found in REJECT_EXTENDED_RANGES mode.");
}
} else { // Basic range
list.add(lr);
}
}
return filterBasic(list, tags);
}
}
private static List<String> filterBasic(List<LanguageRange> priorityList,
Collection<String> tags) {
int splitIndex = splitRanges(priorityList);
List<LanguageRange> nonZeroRanges;
List<LanguageRange> zeroRanges;
if (splitIndex != -1) {
nonZeroRanges = priorityList.subList(0, splitIndex);
zeroRanges = priorityList.subList(splitIndex, priorityList.size());
} else {
nonZeroRanges = priorityList;
zeroRanges = List.of();
}
List<String> list = new ArrayList<>();
for (LanguageRange lr : nonZeroRanges) {
String range = lr.getRange();
if (range.equals("*")) {
tags = removeTagsMatchingBasicZeroRange(zeroRanges, tags);
return new ArrayList<String>(tags);
} else {
for (String tag : tags) {
// change to lowercase for case-insensitive matching
String lowerCaseTag = tag.toLowerCase(Locale.ROOT);
if (lowerCaseTag.startsWith(range)) {
int len = range.length();
if ((lowerCaseTag.length() == len
|| lowerCaseTag.charAt(len) == '-')
&& !caseInsensitiveMatch(list, lowerCaseTag)
&& !shouldIgnoreFilterBasicMatch(zeroRanges,
lowerCaseTag)) {
// preserving the case of the input tag
list.add(tag);
}
}
}
}
}
return list;
}
/**
* Removes the tag(s) which are falling in the basic exclusion range(s) i.e
* range(s) with q=0 and returns the updated collection. If the basic
* language ranges contains '*' as one of its non zero range then instead of
* returning all the tags, remove those which are matching the range with
* quality weight q=0.
*/
private static Collection<String> removeTagsMatchingBasicZeroRange(
List<LanguageRange> zeroRange, Collection<String> tags) {
if (zeroRange.isEmpty()) {
tags = removeDuplicates(tags);
return tags;
}
List<String> matchingTags = new ArrayList<>();
for (String tag : tags) {
// change to lowercase for case-insensitive matching
String lowerCaseTag = tag.toLowerCase(Locale.ROOT);
if (!shouldIgnoreFilterBasicMatch(zeroRange, lowerCaseTag)
&& !caseInsensitiveMatch(matchingTags, lowerCaseTag)) {
matchingTags.add(tag); // preserving the case of the input tag
}
}
return matchingTags;
}
/**
* Remove duplicate tags from the given {@code tags} by
* ignoring case considerations.
*/
private static Collection<String> removeDuplicates(
Collection<String> tags) {
Set<String> distinctTags = new TreeSet<>(String.CASE_INSENSITIVE_ORDER);
return tags.stream().filter(x -> distinctTags.add(x))
.collect(Collectors.toList());
}
/**
* Returns true if the given {@code list} contains an element which matches
* with the given {@code tag} ignoring case considerations.
*/
private static boolean caseInsensitiveMatch(List<String> list, String tag) {
return list.stream().anyMatch((element)
-> (element.equalsIgnoreCase(tag)));
}
/**
* The tag which is falling in the basic exclusion range(s) should not
* be considered as the matching tag. Ignores the tag matching with the
* non-zero ranges, if the tag also matches with one of the basic exclusion
* ranges i.e. range(s) having quality weight q=0
*/
private static boolean shouldIgnoreFilterBasicMatch(
List<LanguageRange> zeroRange, String tag) {
if (zeroRange.isEmpty()) {
return false;
}
for (LanguageRange lr : zeroRange) {
String range = lr.getRange();
if (range.equals("*")) {
return true;
}
if (tag.startsWith(range)) {
int len = range.length();
if ((tag.length() == len || tag.charAt(len) == '-')) {
return true;
}
}
}
return false;
}
private static List<String> filterExtended(List<LanguageRange> priorityList,
Collection<String> tags) {
int splitIndex = splitRanges(priorityList);
List<LanguageRange> nonZeroRanges;
List<LanguageRange> zeroRanges;
if (splitIndex != -1) {
nonZeroRanges = priorityList.subList(0, splitIndex);
zeroRanges = priorityList.subList(splitIndex, priorityList.size());
} else {
nonZeroRanges = priorityList;
zeroRanges = List.of();
}
List<String> list = new ArrayList<>();
for (LanguageRange lr : nonZeroRanges) {
String range = lr.getRange();
if (range.equals("*")) {
tags = removeTagsMatchingExtendedZeroRange(zeroRanges, tags);
return new ArrayList<String>(tags);
}
String[] rangeSubtags = range.split("-");
for (String tag : tags) {
// change to lowercase for case-insensitive matching
String lowerCaseTag = tag.toLowerCase(Locale.ROOT);
String[] tagSubtags = lowerCaseTag.split("-");
if (!rangeSubtags[0].equals(tagSubtags[0])
&& !rangeSubtags[0].equals("*")) {
continue;
}
int rangeIndex = matchFilterExtendedSubtags(rangeSubtags,
tagSubtags);
if (rangeSubtags.length == rangeIndex
&& !caseInsensitiveMatch(list, lowerCaseTag)
&& !shouldIgnoreFilterExtendedMatch(zeroRanges,
lowerCaseTag)) {
list.add(tag); // preserve the case of the input tag
}
}
}
return list;
}
/**
* Removes the tag(s) which are falling in the extended exclusion range(s)
* i.e range(s) with q=0 and returns the updated collection. If the extended
* language ranges contains '*' as one of its non zero range then instead of
* returning all the tags, remove those which are matching the range with
* quality weight q=0.
*/
private static Collection<String> removeTagsMatchingExtendedZeroRange(
List<LanguageRange> zeroRange, Collection<String> tags) {
if (zeroRange.isEmpty()) {
tags = removeDuplicates(tags);
return tags;
}
List<String> matchingTags = new ArrayList<>();
for (String tag : tags) {
// change to lowercase for case-insensitive matching
String lowerCaseTag = tag.toLowerCase(Locale.ROOT);
if (!shouldIgnoreFilterExtendedMatch(zeroRange, lowerCaseTag)
&& !caseInsensitiveMatch(matchingTags, lowerCaseTag)) {
matchingTags.add(tag); // preserve the case of the input tag
}
}
return matchingTags;
}
/**
* The tag which is falling in the extended exclusion range(s) should
* not be considered as the matching tag. Ignores the tag matching with the
* non zero range(s), if the tag also matches with one of the extended
* exclusion range(s) i.e. range(s) having quality weight q=0
*/
private static boolean shouldIgnoreFilterExtendedMatch(
List<LanguageRange> zeroRange, String tag) {
if (zeroRange.isEmpty()) {
return false;
}
String[] tagSubtags = tag.split("-");
for (LanguageRange lr : zeroRange) {
String range = lr.getRange();
if (range.equals("*")) {
return true;
}
String[] rangeSubtags = range.split("-");
if (!rangeSubtags[0].equals(tagSubtags[0])
&& !rangeSubtags[0].equals("*")) {
continue;
}
int rangeIndex = matchFilterExtendedSubtags(rangeSubtags,
tagSubtags);
if (rangeSubtags.length == rangeIndex) {
return true;
}
}
return false;
}
private static int matchFilterExtendedSubtags(String[] rangeSubtags,
String[] tagSubtags) {
int rangeIndex = 1;
int tagIndex = 1;
while (rangeIndex < rangeSubtags.length
&& tagIndex < tagSubtags.length) {
if (rangeSubtags[rangeIndex].equals("*")) {
rangeIndex++;
} else if (rangeSubtags[rangeIndex]
.equals(tagSubtags[tagIndex])) {
rangeIndex++;
tagIndex++;
} else if (tagSubtags[tagIndex].length() == 1
&& !tagSubtags[tagIndex].equals("*")) {
break;
} else {
tagIndex++;
}
}
return rangeIndex;
}
public static Locale lookup(List<LanguageRange> priorityList,
Collection<Locale> locales) {
if (priorityList.isEmpty() || locales.isEmpty()) {
return null;
}
// Create a list of language tags to be matched.
List<String> tags = new ArrayList<>();
for (Locale locale : locales) {
tags.add(locale.toLanguageTag());
}
// Look up a language tags.
String lookedUpTag = lookupTag(priorityList, tags);
if (lookedUpTag == null) {
return null;
} else {
return Locale.forLanguageTag(lookedUpTag);
}
}
public static String lookupTag(List<LanguageRange> priorityList,
Collection<String> tags) {
if (priorityList.isEmpty() || tags.isEmpty()) {
return null;
}
int splitIndex = splitRanges(priorityList);
List<LanguageRange> nonZeroRanges;
List<LanguageRange> zeroRanges;
if (splitIndex != -1) {
nonZeroRanges = priorityList.subList(0, splitIndex);
zeroRanges = priorityList.subList(splitIndex, priorityList.size());
} else {
nonZeroRanges = priorityList;
zeroRanges = List.of();
}
for (LanguageRange lr : nonZeroRanges) {
String range = lr.getRange();
// Special language range ("*") is ignored in lookup.
if (range.equals("*")) {
continue;
}
String rangeForRegex = range.replace("*", "\\p{Alnum}*");
while (!rangeForRegex.isEmpty()) {
for (String tag : tags) {
// change to lowercase for case-insensitive matching
String lowerCaseTag = tag.toLowerCase(Locale.ROOT);
if (lowerCaseTag.matches(rangeForRegex)
&& !shouldIgnoreLookupMatch(zeroRanges, lowerCaseTag)) {
return tag; // preserve the case of the input tag
}
}
// Truncate from the end....
rangeForRegex = truncateRange(rangeForRegex);
}
}
return null;
}
/**
* The tag which is falling in the exclusion range(s) should not be
* considered as the matching tag. Ignores the tag matching with the
* non zero range(s), if the tag also matches with one of the exclusion
* range(s) i.e. range(s) having quality weight q=0.
*/
private static boolean shouldIgnoreLookupMatch(List<LanguageRange> zeroRange,
String tag) {
for (LanguageRange lr : zeroRange) {
String range = lr.getRange();
// Special language range ("*") is ignored in lookup.
if (range.equals("*")) {
continue;
}
String rangeForRegex = range.replace("*", "\\p{Alnum}*");
while (!rangeForRegex.isEmpty()) {
if (tag.matches(rangeForRegex)) {
return true;
}
// Truncate from the end....
rangeForRegex = truncateRange(rangeForRegex);
}
}
return false;
}
/* Truncate the range from end during the lookup match */
private static String truncateRange(String rangeForRegex) {
int index = rangeForRegex.lastIndexOf('-');
if (index >= 0) {
rangeForRegex = rangeForRegex.substring(0, index);
// if range ends with an extension key, truncate it.
index = rangeForRegex.lastIndexOf('-');
if (index >= 0 && index == rangeForRegex.length() - 2) {
rangeForRegex
= rangeForRegex.substring(0, rangeForRegex.length() - 2);
}
} else {
rangeForRegex = "";
}
return rangeForRegex;
}
/* Returns the split index of the priority list, if it contains
* language range(s) with quality weight as 0 i.e. q=0, else -1
*/
private static int splitRanges(List<LanguageRange> priorityList) {
int size = priorityList.size();
for (int index = 0; index < size; index++) {
LanguageRange range = priorityList.get(index);
if (range.getWeight() == 0) {
return index;
}
}
return -1; // no q=0 range exists
}
public static List<LanguageRange> parse(String ranges) {
ranges = ranges.replace(" ", "").toLowerCase(Locale.ROOT);
if (ranges.startsWith("accept-language:")) {
ranges = ranges.substring(16); // delete unnecessary prefix
}
String[] langRanges = ranges.split(",");
List<LanguageRange> list = new ArrayList<>(langRanges.length);
List<String> tempList = new ArrayList<>();
int numOfRanges = 0;
for (String range : langRanges) {
int index;
String r;
double w;
if ((index = range.indexOf(";q=")) == -1) {
r = range;
w = MAX_WEIGHT;
} else {
r = range.substring(0, index);
index += 3;
try {
w = Double.parseDouble(range.substring(index));
}
catch (Exception e) {
throw new IllegalArgumentException("weight=\""
+ range.substring(index)
+ "\" for language range \"" + r + "\"");
}
if (w < MIN_WEIGHT || w > MAX_WEIGHT) {
throw new IllegalArgumentException("weight=" + w
+ " for language range \"" + r
+ "\". It must be between " + MIN_WEIGHT
+ " and " + MAX_WEIGHT + ".");
}
}
if (!tempList.contains(r)) {
LanguageRange lr = new LanguageRange(r, w);
index = numOfRanges;
for (int j = 0; j < numOfRanges; j++) {
if (list.get(j).getWeight() < w) {
index = j;
break;
}
}
list.add(index, lr);
numOfRanges++;
tempList.add(r);
// Check if the range has an equivalent using IANA LSR data.
// If yes, add it to the User's Language Priority List as well.
// aa-XX -> aa-YY
String equivalent;
if ((equivalent = getEquivalentForRegionAndVariant(r)) != null
&& !tempList.contains(equivalent)) {
list.add(index+1, new LanguageRange(equivalent, w));
numOfRanges++;
tempList.add(equivalent);
}
String[] equivalents;
if ((equivalents = getEquivalentsForLanguage(r)) != null) {
for (String equiv: equivalents) {
// aa-XX -> bb-XX(, cc-XX)
if (!tempList.contains(equiv)) {
list.add(index+1, new LanguageRange(equiv, w));
numOfRanges++;
tempList.add(equiv);
}
// bb-XX -> bb-YY(, cc-YY)
equivalent = getEquivalentForRegionAndVariant(equiv);
if (equivalent != null
&& !tempList.contains(equivalent)) {
list.add(index+1, new LanguageRange(equivalent, w));
numOfRanges++;
tempList.add(equivalent);
}
}
}
}
}
return list;
}
/**
* A faster alternative approach to String.replaceFirst(), if the given
* string is a literal String, not a regex.
*/
private static String replaceFirstSubStringMatch(String range,
String substr, String replacement) {
int pos = range.indexOf(substr);
if (pos == -1) {
return range;
} else {
return range.substring(0, pos) + replacement
+ range.substring(pos + substr.length());
}
}
private static String[] getEquivalentsForLanguage(String range) {
String r = range;
while (!r.isEmpty()) {
if (LocaleEquivalentMaps.singleEquivMap.containsKey(r)) {
String equiv = LocaleEquivalentMaps.singleEquivMap.get(r);
// Return immediately for performance if the first matching
// subtag is found.
return new String[]{replaceFirstSubStringMatch(range,
r, equiv)};
} else if (LocaleEquivalentMaps.multiEquivsMap.containsKey(r)) {
String[] equivs = LocaleEquivalentMaps.multiEquivsMap.get(r);
String[] result = new String[equivs.length];
for (int i = 0; i < equivs.length; i++) {
result[i] = replaceFirstSubStringMatch(range,
r, equivs[i]);
}
return result;
}
// Truncate the last subtag simply.
int index = r.lastIndexOf('-');
if (index == -1) {
break;
}
r = r.substring(0, index);
}
return null;
}
private static String getEquivalentForRegionAndVariant(String range) {
int extensionKeyIndex = getExtentionKeyIndex(range);
for (String subtag : LocaleEquivalentMaps.regionVariantEquivMap.keySet()) {
int index;
if ((index = range.indexOf(subtag)) != -1) {
// Check if the matching text is a valid region or variant.
if (extensionKeyIndex != Integer.MIN_VALUE
&& index > extensionKeyIndex) {
continue;
}
int len = index + subtag.length();
if (range.length() == len || range.charAt(len) == '-') {
return replaceFirstSubStringMatch(range, subtag,
LocaleEquivalentMaps.regionVariantEquivMap
.get(subtag));
}
}
}
return null;
}
private static int getExtentionKeyIndex(String s) {
char[] c = s.toCharArray();
int index = Integer.MIN_VALUE;
for (int i = 1; i < c.length; i++) {
if (c[i] == '-') {
if (i - index == 2) {
return index;
} else {
index = i;
}
}
}
return Integer.MIN_VALUE;
}
public static List<LanguageRange> mapEquivalents(
List<LanguageRange>priorityList,
Map<String, List<String>> map) {
if (priorityList.isEmpty()) {
return new ArrayList<>(); // need to return a empty mutable List
}
if (map == null || map.isEmpty()) {
return new ArrayList<LanguageRange>(priorityList);
}
// Create a map, key=originalKey.toLowerCaes(), value=originalKey
Map<String, String> keyMap = new HashMap<>();
for (String key : map.keySet()) {
keyMap.put(key.toLowerCase(Locale.ROOT), key);
}
List<LanguageRange> list = new ArrayList<>();
for (LanguageRange lr : priorityList) {
String range = lr.getRange();
String r = range;
boolean hasEquivalent = false;
while (!r.isEmpty()) {
if (keyMap.containsKey(r)) {
hasEquivalent = true;
List<String> equivalents = map.get(keyMap.get(r));
if (equivalents != null) {
int len = r.length();
for (String equivalent : equivalents) {
list.add(new LanguageRange(equivalent.toLowerCase(Locale.ROOT)
+ range.substring(len),
lr.getWeight()));
}
}
// Return immediately if the first matching subtag is found.
break;
}
// Truncate the last subtag simply.
int index = r.lastIndexOf('-');
if (index == -1) {
break;
}
r = r.substring(0, index);
}
if (!hasEquivalent) {
list.add(lr);
}
}
return list;
}
private LocaleMatcher() {}
}