Java tutorial
///////////////////////////////////////////////////////////////////////////// // // Project ProjectForge Community Edition // www.projectforge.org // // Copyright (C) 2001-2013 Kai Reinhard (k.reinhard@micromata.de) // // ProjectForge is dual-licensed. // // This community edition is free software; you can redistribute it and/or // modify it under the terms of the GNU General Public License as published // by the Free Software Foundation; version 3 of the License. // // This community edition is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General // Public License for more details. // // You should have received a copy of the GNU General Public License along // with this program; if not, see http://www.gnu.org/licenses/. // ///////////////////////////////////////////////////////////////////////////// package org.projectforge.web.wicket.converter; import java.util.HashMap; import java.util.Locale; import java.util.Map; import org.apache.commons.lang.StringUtils; import org.apache.wicket.util.convert.IConverter; /** * @author Kai Reinhard (k.reinhard@micromata.de) */ public class LanguageConverter implements IConverter { private static final long serialVersionUID = 2554286471459716772L; /** * Contains a map for all used user locales. Each map contains the display name of a locale as key and the locale object as value. */ private final static Map<Locale, Map<String, Locale>> localeMap = new HashMap<Locale, Map<String, Locale>>(); public static final String getLanguageAsString(final Locale language, final Locale locale) { if (language == null) { return ""; } return language.getDisplayName(locale); } public static final Locale getLanguage(final String language, final Locale locale) { synchronized (localeMap) { if (localeMap.containsKey(locale) == false) { final Map<String, Locale> m = new HashMap<String, Locale>(); for (final Locale lc : Locale.getAvailableLocales()) { m.put(lc.getDisplayName(locale), lc); } localeMap.put(locale, m); } } return localeMap.get(locale).get(language); } /** * Will be called if convert to Object fails. Does nothing at default. */ protected void error() { } /** * Uses all available locales and compares the string value with the display name (in the given locale). * * @param value The string representation. * @param locale The user's locale to use the correct translation. * @see org.apache.wicket.util.convert.IConverter#convertToObject(java.lang.String, java.util.Locale) */ @Override public Object convertToObject(final String value, final Locale locale) { if (StringUtils.isEmpty(value) == true) { return null; } final String lvalue = value.toLowerCase(locale); for (final Locale lc : Locale.getAvailableLocales()) { if (getLanguageAsString(lc, locale).toLowerCase().equals(lvalue) == true) { return lc; } } error(); return null; } /** * @param value The locale to convert. * @param locale The user's locale to use the correct translation. * @see org.apache.wicket.util.convert.IConverter#convertToString(java.lang.Object, java.util.Locale) * @see Locale#getDisplayCountry(Locale) */ @Override public String convertToString(final Object value, final Locale locale) { if (value == null) { return null; } final Locale language = (Locale) value; return getLanguageAsString(language, locale); } }