TranslatedString.java

package org.opentripplanner.util;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Locale;
import java.util.Map;
import java.util.Map.Entry;

/**
 * This is for translated strings for which translations are read from OSM or GTFS alerts.
 *
 * This can be translated street names, GTFS alerts and notes.
 * @author Hannes Junnila
 */
public class TranslatedString implements I18NString, Serializable {

    /**
     * Store all translations, so we don't get memory overhead for identical strings
     * As this is static, it isn't serialized when saving the graph.
     */
    private static HashMap<Map<String, String>, I18NString> intern = new HashMap<>();

    private Map<String, String> translations = new HashMap<>();

    private TranslatedString(Map<String, String> translations) {
        for (Map.Entry<String, String> i : translations.entrySet()) {
            if (i.getKey() == null){
                this.translations.put(null, i.getValue());
            } else {
                this.translations.put(i.getKey().toLowerCase(), i.getValue());
            }
        }
    }

    @Override
    public boolean equals(Object other) {
        return (other instanceof TranslatedString) && this.translations.equals(((TranslatedString)other).translations);
    }

    /**
     * Gets an interned I18NString.
     * If the translations only have a single value, return a NonTranslatedString, otherwise a TranslatedString
     *
     * @param translations A Map of languages and translations, a null language is the default translation
     */
    public static I18NString getI18NString(Map<String, String> translations) {
        if (intern.containsKey(translations)) {
            return intern.get(translations);
        }
        else {
            I18NString ret;
            // Check if we only have one name, even under multiple languages
            if (new HashSet<>(translations.values()).size() < 2) {
                ret = new NonLocalizedString(translations.values().iterator().next());
            } else {
                ret = new TranslatedString(translations);
            }
            intern.put(translations, ret);
            return ret;
        }
    }

    /**
     * @return The available languages
     */
    public Collection<String> getLanguages() {
        return translations.keySet();
    }

    /**
     * @return The available translations
     */
    public List<Entry<String,String>> getTranslations() {
        return new ArrayList<Entry<String, String>>(translations.entrySet());
    }

    /**
     * @return The default translation
     */
    @Override
    public String toString() {
        return translations.containsKey(null) ? translations.get(null) : translations.values().iterator().next();
    }

    /**
     * @param locale Wanted locale
     * @return The translation in the wanted language if it exists, otherwise the default translation
     */
    @Override
    public String toString(Locale locale) {
        String language = null;
        if (locale != null) {
            language = locale.getLanguage().toLowerCase();
        }
        return translations.containsKey(language) ? translations.get(language) : toString();
    }
}