Apache Commons Codec library provides implementations of common encoders and decoders such as Base64, Hex, Phonetic and URLs.

Apache Commons Codec Source Code files are provided in both binary packge (commons-codec-3.15-bin.zip) and source package (commons-codec-3.15-src.zip). You can download them at Apache Commons Codec Website.

Apache Commons Codec Source Code has no dependencies. You can compile it to generate your own version of Apache Commons Codec JAR file.

The source code of Apache Commons Codec 1.15 is provided below:

⏎ org/apache/commons/codec/language/bm/Languages.java

/*
 * 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.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;

import org.apache.commons.codec.Resources;

/**
 * Language codes.
 * <p>
 * Language codes are typically loaded from resource files. These are UTF-8
 * encoded text files. They are systematically named following the pattern:
 * <blockquote>org/apache/commons/codec/language/bm/${{@link NameType#getName()}
 * languages.txt</blockquote>
 * <p>
 * The format of these resources is the following:
 * <ul>
 * <li><b>Language:</b> a single string containing no whitespace</li>
 * <li><b>End-of-line comments:</b> Any occurrence of '//' will cause all text
 * following on that line to be discarded as a comment.</li>
 * <li><b>Multi-line comments:</b> Any line starting with '/*' will start
 * multi-line commenting mode. This will skip all content until a line ending in
 * '*' and '/' is found.</li>
 * <li><b>Blank lines:</b> All blank lines will be skipped.</li>
 * </ul>
 * <p>
 * Ported from language.php
 * <p>
 * This class is immutable and thread-safe.
 *
 * @since 1.6
 */
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<String> 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<String> languages;

        private SomeLanguages(final Set<String> 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<String> 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<String> 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<String> 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<NameType, Languages> 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<String> ls = new HashSet<>();
        try (final Scanner lsScanner = new Scanner(Resources.getInputStream(languagesResourceName),
                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<String> 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<String> languages) {
        this.languages = languages;
    }

    public Set<String> getLanguages() {
        return this.languages;
    }
}

⏎ org/apache/commons/codec/language/bm/Languages.java

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File name: commons-codec-1.15-sources.jar
File size: 364441 bytes
Release date: 2020-09-01
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