Java tutorial
/* * Demoiselle Framework * Copyright (C) 2010 SERPRO * ---------------------------------------------------------------------------- * This file is part of Demoiselle Framework. * * Demoiselle Framework is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public License version 3 * as published by the Free Software Foundation. * * This program 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 Lesser General Public License version 3 * along with this program; if not, see <http://www.gnu.org/licenses/> * or write to the Free Software Foundation, Inc., 51 Franklin Street, * Fifth Floor, Boston, MA 02110-1301, USA. * ---------------------------------------------------------------------------- * Este arquivo parte do Framework Demoiselle. * * O Framework Demoiselle um software livre; voc pode redistribu-lo e/ou * modific-lo dentro dos termos da GNU LGPL verso 3 como publicada pela Fundao * do Software Livre (FSF). * * Este programa distribudo na esperana que possa ser til, mas SEM NENHUMA * GARANTIA; sem uma garantia implcita de ADEQUAO a qualquer MERCADO ou * APLICAO EM PARTICULAR. Veja a Licena Pblica Geral GNU/LGPL em portugus * para maiores detalhes. * * Voc deve ter recebido uma cpia da GNU LGPL verso 3, sob o ttulo * "LICENCA.txt", junto com esse programa. Se no, acesse <http://www.gnu.org/licenses/> * ou escreva para a Fundao do Software Livre (FSF) Inc., * 51 Franklin St, Fifth Floor, Boston, MA 02111-1301, USA. */ package br.gov.frameworkdemoiselle.internal.implementation; import static br.gov.frameworkdemoiselle.annotation.Priority.MIN_PRIORITY; import java.io.Serializable; import java.util.ArrayList; import java.util.List; import br.gov.frameworkdemoiselle.annotation.Priority; import br.gov.frameworkdemoiselle.configuration.ConfigurationException; import br.gov.frameworkdemoiselle.internal.producer.ResourceBundleProducer; import br.gov.frameworkdemoiselle.util.ResourceBundle; public final class StrategySelector implements Serializable { public static final int CORE_PRIORITY = MIN_PRIORITY; public static final int EXTENSIONS_L1_PRIORITY = CORE_PRIORITY - 100; public static final int EXTENSIONS_L2_PRIORITY = EXTENSIONS_L1_PRIORITY - 100; public static final int COMPONENTS_PRIORITY = EXTENSIONS_L2_PRIORITY - 100; private static final long serialVersionUID = 1L; private static ResourceBundle bundle; private StrategySelector() { } private static ResourceBundle getBundle() { if (bundle == null) { bundle = ResourceBundleProducer.create("demoiselle-core-bundle"); } return bundle; } public static <T> Class<? extends T> getClass(Class<T> type, List<Class<? extends T>> options) throws ConfigurationException { Class<? extends T> selected = null; for (Class<? extends T> option : options) { if (selected == null || getPriority(option) < getPriority(selected)) { selected = option; } } checkForAmbiguity(type, selected, options); return selected; } private static <T> void checkForAmbiguity(Class<T> type, Class<? extends T> selected, List<Class<? extends T>> options) throws ConfigurationException { int selectedPriority = getPriority(selected); List<Class<? extends T>> ambiguous = new ArrayList<Class<? extends T>>(); for (Class<? extends T> option : options) { if (selected != option && selectedPriority == getPriority(option)) { ambiguous.add(option); } } if (!ambiguous.isEmpty()) { ambiguous.add(selected); String message = getExceptionMessage(type, ambiguous); throw new ConfigurationException(message); } } private static <T> String getExceptionMessage(Class<T> type, List<Class<? extends T>> ambiguous) { StringBuffer classes = new StringBuffer(); int i = 0; for (Class<? extends T> clazz : ambiguous) { if (i++ != 0) { classes.append(", "); } classes.append(clazz.getCanonicalName()); } return getBundle().getString("ambiguous-strategy-resolution", type.getCanonicalName(), classes.toString()); } private static <T> int getPriority(Class<T> type) { int result = Priority.MAX_PRIORITY; Priority priority = type.getAnnotation(Priority.class); if (priority != null) { result = priority.value(); } return result; } // public static <T> T getExplicitReference(String configKey, Class<T> strategyType, Class<T> defaultType) { // Class<T> selectedType = loadSelected(configKey, strategyType, defaultType); // return Beans.getReference(selectedType); // } // // @SuppressWarnings("unchecked") // private static <T> Class<T> loadSelected(String configKey, Class<T> strategyType, Class<T> defaultType) { // ResourceBundle bundle = ResourceBundleProducer.create("demoiselle-core-bundle", // Beans.getReference(Locale.class)); // Class<T> result = null; // String canonicalName = null; // String typeName = strategyType.getSimpleName().toLowerCase(); // String key = null; // try { // URL url = ConfigurationLoader.getResourceAsURL("demoiselle.properties"); // Configuration config = new PropertiesConfiguration(url); // canonicalName = config.getString(configKey, defaultType.getCanonicalName()); // ClassLoader classLoader = ConfigurationLoader.getClassLoaderForClass(canonicalName); // if (classLoader == null) { // classLoader = Thread.currentThread().getContextClassLoader(); // } // result = (Class<T>) Class.forName(canonicalName, false, classLoader); // result.asSubclass(strategyType); // } catch (org.apache.commons.configuration.ConfigurationException cause) { // throw new ConfigurationException(bundle.getString("file-not-found", "demoiselle.properties")); // } catch (ClassNotFoundException cause) { // key = Strings.getString("{0}-class-not-found", typeName); // throw new ConfigurationException(bundle.getString(key, canonicalName)); // } catch (FileNotFoundException e) { // throw new ConfigurationException(bundle.getString("file-not-found", "demoiselle.properties")); // } catch (ClassCastException cause) { // key = Strings.getString("{0}-class-must-be-of-type", typeName); // throw new ConfigurationException(bundle.getString(key, canonicalName, strategyType)); // } // return result; // } }