common/util/LocaleUtil.java

/*
 * Copyright 2004-2007 The Portal Application Laboratory Team.
 *
 * Licensed 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 jp.sf.pal.common.util;

import java.util.Locale;
import java.util.StringTokenizer;

public class LocaleUtil {
    private static final String DEFAULT_DELIM = "_";

    public static Locale fallback(Locale locale1, Locale locale2) {
        if (locale1 == null && locale2 == null) {
            return null;
        }
        if ((locale1 == null && locale2 != null)
                || (locale1 != null && locale2 == null)) {
            return null;
        }
        if (locale1.equals(locale2)) {
            return locale1;
        }

        if (locale1.getLanguage() != null && locale1.getCountry() != null
                && locale1.getLanguage().equals(locale2.getLanguage())
                && locale1.getCountry().equals(locale2.getCountry())) {
            return new Locale(locale1.getLanguage(), locale2.getCountry());
        }

        if (locale1.getLanguage() != null
                && locale1.getLanguage().equals(locale2.getLanguage())) {
            return new Locale(locale1.getLanguage());
        }

        return null;
    }

    public static String convert(Locale locale) {
        return convert(locale, DEFAULT_DELIM);
    }

    public static String convert(Locale locale, String delim) {
        if (locale == null) {
            return null;
        }
        String country = locale.getCountry();
        String language = locale.getLanguage();
        String variant = locale.getVariant();
        StringBuffer buffer = new StringBuffer(40);
        if (language != null) {
            buffer.append(language);
        }
        buffer.append(delim);

        if (country != null) {
            buffer.append(country);
        }
        buffer.append(delim);

        if (variant != null) {
            buffer.append(variant);
        }

        return buffer.toString().trim();
    }

    public static Locale convert(String localeString) {
        return convert(localeString, DEFAULT_DELIM);
    }

    public static Locale convert(String localeString, String delim) {
        if (localeString == null) {
            return null;
        }
        StringTokenizer tokenizer = new StringTokenizer(localeString,
                DEFAULT_DELIM);

        String language = tokenizer.nextToken().trim();
        String country = null;
        String variant = null;
        if (tokenizer.hasMoreTokens()) {
            country = tokenizer.nextToken().trim();
        }

        if (tokenizer.hasMoreTokens()) {
            variant = tokenizer.nextToken().trim();
        }

        if (country != null && language != null && variant != null) {
            return new Locale(language, country, variant);
        } else if (country != null && language != null) {
            return new Locale(language, country);
        } else if (language != null) {
            return new Locale(language, ""); // JDK 1.3 compatibility
        } else {
            return null;
        }

    }

}