Java tutorial
/* * WebTop Services is a Web Application framework developed by Sonicle S.r.l. * Copyright (C) 2014 Sonicle S.r.l. * * This program is free software; you can redistribute it and/or modify it under * the terms of the GNU Affero General Public License version 3 as published by * the Free Software Foundation with the addition of the following permission * added to Section 15 as permitted in Section 7(a): FOR ANY PART OF THE COVERED * WORK IN WHICH THE COPYRIGHT IS OWNED BY SONICLE, SONICLE DISCLAIMS THE * WARRANTY OF NON INFRINGEMENT OF THIRD PARTY RIGHTS. * * 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 Affero General Public License * 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. * * You can contact Sonicle S.r.l. at email address sonicle@sonicle.com * * The interactive user interfaces in modified source and object code versions * of this program must display Appropriate Legal Notices, as required under * Section 5 of the GNU Affero General Public License version 3. * * In accordance with Section 7(b) of the GNU Affero General Public License * version 3, these Appropriate Legal Notices must retain the display of the * Sonicle logo and Sonicle copyright notice. If the display of the logo is not * reasonably feasible for technical reasons, the Appropriate Legal Notices must * display the words "Copyright (C) 2014 Sonicle S.r.l.". */ package com.sonicle.webtop.core.app.util; import java.lang.annotation.Annotation; import java.util.Arrays; import java.util.Set; import java.util.stream.Collectors; import org.apache.commons.lang3.StringUtils; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * * @author malbinola */ public class ClassHelper { private static final Logger LOGGER = LoggerFactory.getLogger(ClassHelper.class); public static Class loadClass(boolean skipIfBlank, String className, Class requiredParentClass, String targetDescription) { if (skipIfBlank && StringUtils.isBlank(className)) { return null; } else { return loadClass(className, requiredParentClass, targetDescription); } } public static Class loadClass(String className, Class requiredParentClass, String targetDescription) { String tdesc = StringUtils.defaultIfBlank(targetDescription, "Target"); try { Class clazz = Class.forName(className); if (!requiredParentClass.isAssignableFrom(clazz)) throw new ClassCastException(); return clazz; } catch (ClassNotFoundException ex) { LOGGER.debug("{} class not found [{}]", tdesc, className); } catch (ClassCastException ex) { LOGGER.warn("A valid {} class must extends '{}' class", tdesc, requiredParentClass.toString()); } catch (Throwable t) { LOGGER.error("Unable to load class [{}]", className, t); } return null; } public static boolean isImplementingInterface(Class clazz, Class interfaceClass) { if (clazz == null) return false; if (interfaceClass == null) return false; return interfaceClass.isAssignableFrom(clazz); } public static Annotation getClassAnnotation(Class clazz, Class annotationClass) { if (clazz == null) return null; Set<Annotation> annotations = getClassAnnotations(clazz, annotationClass); return annotations.isEmpty() ? null : annotations.iterator().next(); } public static Set<Annotation> getClassAnnotations(Class clazz, Class annotationClass) { if (clazz == null) return null; Annotation[] annotations = clazz.getAnnotationsByType(annotationClass); return Arrays.stream(annotations).unordered().collect(Collectors.toSet()); } }