org.xmlactions.action.config.LanguageLocale.java Source code

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Here is the source code for org.xmlactions.action.config.LanguageLocale.java

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/*
 * Copyright (C) Mike Murphy 2003-2015 <mike.murphy@xmlactions.org><mwjmurphy@gmail.com>
 *
 * 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 org.xmlactions.action.config;

import java.util.Locale;

import org.apache.commons.lang.StringUtils;
import org.apache.commons.lang.Validate;

/**
 * This class manages the language locale.
 * <p>
 *   Using an entry on the page such as ${lang:key} you can retrieve the language value for that key. 
 * </p> 
 * <p>
 *    The replacement pattern is <b>"lang:key:resouce:language:country:variant"</b>
 *  <br/> where:
 *  <ul>
 *  <li>"lang" - states that we want a locale language replacement.  This is a required field.</li>
 *    <li>"key" - is the reference to the property key that we want the replacement value for. This is a required field.</li>
 *    <li>"resource" - is the name of the resource file to use. This is an optional field and if not set the default language file will be used.</li>
 *    <li>"language" - is the language to use. Example: "en" (English), "ja" (Japanese), "kok" (Konkani). This is an optional field and if not set the default locale language is used.</li>
 *    <li>"country" - is the country to use. Example: "US" (United States), "FR" (France), "029" (Caribbean). This is an optional field and if not set the default locale language is used.</li>
 *    <li>"variant" - is the language variant we want to use. Example: "polyton" (Polytonic Greek), "POSIX". This is an optional field and if not set the default locale language is used.</li>
 *  </ul>
 * </p>
 * <p>
 *  Example:
 *  <br/> ${lang:application.title} - Will use the default language properties file and get the value for <b>application.title</b>
 *  <br/> ${lang:application.title:jms_services} - Will use the language properties file <b>jms_services</b> and get the value for <b>application.title</b>
 * </p>
 * <p>
 * A default language file is setup for the key <b>default_locale_file</b>. Usually this is configured in the web.properties file loaded by the spring configuration. 
 * </p>
 * 
 * 
 * @author mike.murphy
 *
 */
public class LanguageLocale {

    private String key;
    private String resource;
    private String language;
    private String country;
    private String variant;

    private static final String seperatorChar = ":";

    /**
     * Get a value for key from a language (locale) file.
     * <p>
     * The replacementPattern format is "lang:key:resouce:language:country:variant"
     * <br/>or "lang:key" uses the default resource file and the default locale
     * <br/>or "lang:key:resource" uses the resource file and the default locale
     * <br/>or "lang:key::language" uses the default resource file and the language locale
     * </p>
     * 
     * @param replacementPattern - the replacement pattern that was entered within the StrSubstitution
     * @return the value for key or null if not found.
     * 
     */
    public Object getLang(IExecContext execContext, String replacementPattern) {
        boolean hasLanguage = false;
        boolean hasCountry = false;
        boolean hasVariant = false;

        String parts[] = replacementPattern.split(seperatorChar);
        Validate.notEmpty(parts[1], "Missing key value for [" + replacementPattern + "]");
        key = parts[1];
        if (parts.length > 2) {
            resource = parts[2];
        }
        if (StringUtils.isEmpty(resource)) {
            resource = execContext.getString(IExecContext.DEFAULT_LOCALE_FILE);
            Validate.notEmpty(resource, "No default locale file has been set for ["
                    + IExecContext.DEFAULT_LOCALE_FILE + "] in [" + replacementPattern + "]");
        } else {
            // try if resource is a key to a different value
            String mappedResource = execContext.getString(resource);
            if (mappedResource != null) {
                resource = mappedResource;
            }
        }
        if (parts.length > 3) {
            language = parts[3];
            if (language != null) {
                hasLanguage = true;
            }
        }
        if (parts.length > 4) {
            country = parts[4];
            if (country != null) {
                hasCountry = true;
            }
        }
        if (parts.length > 5) {
            variant = parts[5];
            if (variant != null) {
                hasVariant = true;
            }
        }
        Locale locale = null;
        if (hasLanguage && !(hasCountry | hasVariant)) {
            locale = new Locale(language);
            Locale.setDefault(locale);
        } else if (hasLanguage && hasCountry && !hasVariant) {
            locale = new Locale(language, country);
            Locale.setDefault(locale);
        } else if (hasLanguage && hasCountry && hasVariant) {
            locale = new Locale(language, country, variant);
            Locale.setDefault(locale);
        }
        if (locale != null) {
            Locale defaultLocale = Locale.getDefault();
            try {
                Locale.setDefault(locale);
                return execContext.getLocalizedString(resource, key);
            } finally {
                Locale.setDefault(defaultLocale);
            }
        } else {
            return execContext.getLocalizedString(resource, key);
        }
    }
}