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/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.codec.language.bm;
import java.io.InputStream;
import java.util.Collections;
import java.util.EnumMap;
import java.util.HashSet;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Scanner;
import java.util.Set;
/**
* Language codes.
*
* Language codes are typically loaded from resource files. These are UTF-8 encoded text files. They are
* systematically named following the pattern:
*
org/apache/commons/codec/language/bm/${{@link NameType#getName()} languages.txt
*
* The format of these resources is the following:
*
* - Language: a single string containing no whitespace
* - End-of-line comments: Any occurrence of '//' will cause all text following on that line to be
* discarded as a comment.
* - Multi-line comments: Any line starting with '/*' will start multi-line commenting mode.
* This will skip all content until a line ending in '*' and '/' is found.
* - Blank lines: All blank lines will be skipped.
*
*
* Ported from language.php
*
* This class is immutable and thread-safe.
*
* @since 1.6
* @version $Id$
*/
public class Languages {
// Implementation note: This class is divided into two sections. The first part is a static factory interface that
// exposes org/apache/commons/codec/language/bm/%s_languages.txt for %s in NameType.* as a list of supported
// languages, and a second part that provides instance methods for accessing this set for supported languages.
/**
* A set of languages.
*/
public static abstract class LanguageSet {
public static LanguageSet from(final Set langs) {
return langs.isEmpty() ? NO_LANGUAGES : new SomeLanguages(langs);
}
public abstract boolean contains(String language);
public abstract String getAny();
public abstract boolean isEmpty();
public abstract boolean isSingleton();
public abstract LanguageSet restrictTo(LanguageSet other);
abstract LanguageSet merge(LanguageSet other);
}
/**
* Some languages, explicitly enumerated.
*/
public static final class SomeLanguages extends LanguageSet {
private final Set languages;
private SomeLanguages(final Set languages) {
this.languages = Collections.unmodifiableSet(languages);
}
@Override
public boolean contains(final String language) {
return this.languages.contains(language);
}
@Override
public String getAny() {
return this.languages.iterator().next();
}
public Set getLanguages() {
return this.languages;
}
@Override
public boolean isEmpty() {
return this.languages.isEmpty();
}
@Override
public boolean isSingleton() {
return this.languages.size() == 1;
}
@Override
public LanguageSet restrictTo(final LanguageSet other) {
if (other == NO_LANGUAGES) {
return other;
} else if (other == ANY_LANGUAGE) {
return this;
} else {
final SomeLanguages sl = (SomeLanguages) other;
final Set ls = new HashSet<>(Math.min(languages.size(), sl.languages.size()));
for (final String lang : languages) {
if (sl.languages.contains(lang)) {
ls.add(lang);
}
}
return from(ls);
}
}
@Override
public LanguageSet merge(final LanguageSet other) {
if (other == NO_LANGUAGES) {
return this;
} else if (other == ANY_LANGUAGE) {
return other;
} else {
final SomeLanguages sl = (SomeLanguages) other;
final Set ls = new HashSet<>(languages);
for (final String lang : sl.languages) {
ls.add(lang);
}
return from(ls);
}
}
@Override
public String toString() {
return "Languages(" + languages.toString() + ")";
}
}
public static final String ANY = "any";
private static final Map LANGUAGES = new EnumMap<>(NameType.class);
static {
for (final NameType s : NameType.values()) {
LANGUAGES.put(s, getInstance(langResourceName(s)));
}
}
public static Languages getInstance(final NameType nameType) {
return LANGUAGES.get(nameType);
}
public static Languages getInstance(final String languagesResourceName) {
// read languages list
final Set ls = new HashSet<>();
final InputStream langIS = Languages.class.getClassLoader().getResourceAsStream(languagesResourceName);
if (langIS == null) {
throw new IllegalArgumentException("Unable to resolve required resource: " + languagesResourceName);
}
try (final Scanner lsScanner = new Scanner(langIS, ResourceConstants.ENCODING)) {
boolean inExtendedComment = false;
while (lsScanner.hasNextLine()) {
final String line = lsScanner.nextLine().trim();
if (inExtendedComment) {
if (line.endsWith(ResourceConstants.EXT_CMT_END)) {
inExtendedComment = false;
}
} else {
if (line.startsWith(ResourceConstants.EXT_CMT_START)) {
inExtendedComment = true;
} else if (line.length() > 0) {
ls.add(line);
}
}
}
}
return new Languages(Collections.unmodifiableSet(ls));
}
private static String langResourceName(final NameType nameType) {
return String.format("org/apache/commons/codec/language/bm/%s_languages.txt", nameType.getName());
}
private final Set languages;
/**
* No languages at all.
*/
public static final LanguageSet NO_LANGUAGES = new LanguageSet() {
@Override
public boolean contains(final String language) {
return false;
}
@Override
public String getAny() {
throw new NoSuchElementException("Can't fetch any language from the empty language set.");
}
@Override
public boolean isEmpty() {
return true;
}
@Override
public boolean isSingleton() {
return false;
}
@Override
public LanguageSet restrictTo(final LanguageSet other) {
return this;
}
@Override
public LanguageSet merge(final LanguageSet other) {
return other;
}
@Override
public String toString() {
return "NO_LANGUAGES";
}
};
/**
* Any/all languages.
*/
public static final LanguageSet ANY_LANGUAGE = new LanguageSet() {
@Override
public boolean contains(final String language) {
return true;
}
@Override
public String getAny() {
throw new NoSuchElementException("Can't fetch any language from the any language set.");
}
@Override
public boolean isEmpty() {
return false;
}
@Override
public boolean isSingleton() {
return false;
}
@Override
public LanguageSet restrictTo(final LanguageSet other) {
return other;
}
@Override
public LanguageSet merge(final LanguageSet other) {
return other;
}
@Override
public String toString() {
return "ANY_LANGUAGE";
}
};
private Languages(final Set languages) {
this.languages = languages;
}
public Set getLanguages() {
return this.languages;
}
}