universe@6: /* universe@6: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. universe@6: * universe@6: * Copyright 2017 Mike Becker. All rights reserved. universe@6: * universe@6: * Redistribution and use in source and binary forms, with or without universe@6: * modification, are permitted provided that the following conditions are met: universe@6: * universe@6: * 1. Redistributions of source code must retain the above copyright universe@6: * notice, this list of conditions and the following disclaimer. universe@6: * universe@6: * 2. Redistributions in binary form must reproduce the above copyright universe@6: * notice, this list of conditions and the following disclaimer in the universe@6: * documentation and/or other materials provided with the distribution. universe@6: * universe@6: * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" universe@6: * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE universe@6: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE universe@6: * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE universe@6: * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR universe@6: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF universe@6: * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS universe@6: * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN universe@6: * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) universe@6: * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE universe@6: * POSSIBILITY OF SUCH DAMAGE. universe@6: * universe@6: */ universe@6: package de.uapcore.lightpit; universe@6: universe@10: import java.util.ArrayList; universe@10: import java.util.Collections; universe@10: import java.util.List; universe@10: import java.util.Optional; universe@7: import javax.servlet.Registration; universe@6: import javax.servlet.ServletContext; universe@6: import javax.servlet.ServletContextEvent; universe@6: import javax.servlet.ServletContextListener; universe@6: import javax.servlet.annotation.WebListener; universe@8: import org.slf4j.Logger; universe@8: import org.slf4j.LoggerFactory; universe@6: universe@6: /** universe@6: * Scans registered servlets for LightPIT modules. universe@6: */ universe@6: @WebListener universe@10: public final class ModuleManager implements ServletContextListener { universe@6: universe@8: private static final Logger LOG = LoggerFactory.getLogger(ModuleManager.class); universe@6: universe@6: /** universe@6: * The attribute name in the servlet context under which an instance of this class can be found. universe@6: */ universe@6: public static final String SC_ATTR_NAME = ModuleManager.class.getName(); universe@10: private ServletContext sc; universe@6: universe@10: private final List mainMenu = new ArrayList<>(); universe@10: private final List immutableMainMenu = Collections.unmodifiableList(mainMenu); universe@6: universe@6: @Override universe@6: public void contextInitialized(ServletContextEvent sce) { universe@6: sc = sce.getServletContext(); universe@6: reloadAll(); universe@6: sc.setAttribute(SC_ATTR_NAME, this); universe@6: LOG.info("Module manager injected into ServletContext."); universe@6: } universe@6: universe@6: @Override universe@6: public void contextDestroyed(ServletContextEvent sce) { universe@6: unloadAll(); universe@6: } universe@6: universe@10: private Optional getModuleInfo(Registration reg) { universe@6: try { universe@7: final Class scclass = Class.forName(reg.getClassName()); universe@7: universe@9: final boolean lpservlet = AbstractLightPITServlet.class.isAssignableFrom(scclass); universe@7: final boolean lpmodule = scclass.isAnnotationPresent(LightPITModule.class); universe@7: universe@7: if (lpservlet && !lpmodule) { universe@8: LOG.warn( universe@9: "{} is a LightPIT Servlet but is missing the module annotation.", universe@8: reg.getClassName() universe@8: ); universe@7: } else if (!lpservlet && lpmodule) { universe@8: LOG.warn( universe@9: "{} is annotated as a LightPIT Module but does not extend {}.", universe@9: reg.getClassName(), universe@9: AbstractLightPITServlet.class.getSimpleName() universe@8: ); universe@7: } universe@7: universe@10: if (lpservlet && lpmodule) { universe@10: final Class clazz = scclass; universe@10: final LightPITModule moduleInfo = clazz.getAnnotation(LightPITModule.class); universe@10: return Optional.of(moduleInfo); universe@10: } else { universe@10: return Optional.empty(); universe@10: } universe@6: } catch (ClassNotFoundException ex) { universe@8: LOG.error( universe@9: "Servlet registration refers to class {} which cannot be found by the class loader (Reason: {})", universe@9: reg.getClassName(), universe@9: ex.getMessage() universe@8: ); universe@10: return Optional.empty(); universe@6: } universe@6: } universe@6: universe@10: private void addModuleToMenu(LightPITModule moduleInfo) { universe@10: final Menu menu = new Menu( universe@10: new ResourceKey(moduleInfo.bundleBaseName(), moduleInfo.menuKey()), universe@10: moduleInfo.modulePath() universe@10: ); universe@10: mainMenu.add(menu); universe@10: } universe@10: universe@7: private void handleServletRegistration(String name, Registration reg) { universe@10: final Optional moduleInfo = getModuleInfo(reg); universe@10: if (moduleInfo.isPresent()) { universe@10: addModuleToMenu(moduleInfo.get()); universe@10: universe@8: LOG.info("Module detected: {}", name); universe@6: } else { universe@8: LOG.debug("Servlet {} is no module, skipping.", name); universe@6: } universe@6: } universe@6: universe@6: /** universe@6: * Scans for modules and reloads them all. universe@6: */ universe@6: public void reloadAll() { universe@6: sc.getServletRegistrations().forEach(this::handleServletRegistration); universe@6: LOG.info("Modules loaded."); universe@6: } universe@6: universe@6: /** universe@6: * Unloads all found modules. universe@6: */ universe@6: public void unloadAll() { universe@10: mainMenu.clear(); universe@6: LOG.info("All modules unloaded."); universe@6: } universe@10: universe@10: /** universe@10: * Returns the main menu. universe@10: * @return a list of menus belonging to the main menu universe@10: */ universe@10: public List getMainMenu() { universe@10: return immutableMainMenu; universe@10: } universe@6: }