diff -r cfc3d11884ad -r 27a0fdd7bca7 src/java/de/uapcore/lightpit/ModuleManager.java --- a/src/java/de/uapcore/lightpit/ModuleManager.java Sun Apr 08 16:51:15 2018 +0200 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,231 +0,0 @@ -/* - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. - * - * Copyright 2018 Mike Becker. All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions are met: - * - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" - * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE - * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR - * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF - * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS - * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN - * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) - * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE - * POSSIBILITY OF SUCH DAMAGE. - * - */ -package de.uapcore.lightpit; - -import de.uapcore.lightpit.entities.CoreDAOFactory; -import de.uapcore.lightpit.entities.Module; -import de.uapcore.lightpit.entities.ModuleDao; -import java.sql.Connection; -import java.sql.SQLException; -import java.util.Collections; -import java.util.HashMap; -import java.util.List; -import java.util.Map; -import java.util.Optional; -import java.util.concurrent.atomic.AtomicBoolean; -import java.util.stream.Collectors; -import javax.servlet.Registration; -import javax.servlet.ServletContext; -import javax.servlet.ServletContextEvent; -import javax.servlet.ServletContextListener; -import javax.servlet.annotation.WebListener; -import org.slf4j.Logger; -import org.slf4j.LoggerFactory; - -/** - * Scans registered servlets for LightPIT modules. - */ -@WebListener -public final class ModuleManager implements ServletContextListener { - - private static final Logger LOG = LoggerFactory.getLogger(ModuleManager.class); - - /** - * The attribute name in the servlet context under which an instance of this class can be found. - */ - public static final String SC_ATTR_NAME = ModuleManager.class.getName(); - private ServletContext sc; - - /** - * Maps class names to module information. - */ - private final Map registeredModules = new HashMap<>(); - - /** - * This flag is true, when synchronization is needed. - */ - private final AtomicBoolean dirty = new AtomicBoolean(true); - - @Override - public void contextInitialized(ServletContextEvent sce) { - sc = sce.getServletContext(); - reloadAll(); - sc.setAttribute(SC_ATTR_NAME, this); - LOG.info("Module manager injected into ServletContext."); - } - - @Override - public void contextDestroyed(ServletContextEvent sce) { - unloadAll(); - } - - private Optional getModuleInfo(Registration reg) { - try { - final Class scclass = Class.forName(reg.getClassName()); - - final boolean lpservlet = AbstractLightPITServlet.class.isAssignableFrom(scclass); - final boolean lpmodule = scclass.isAnnotationPresent(LightPITModule.class); - - if (lpservlet && !lpmodule) { - LOG.warn( - "{} is a LightPIT Servlet but is missing the module annotation.", - reg.getClassName() - ); - } else if (!lpservlet && lpmodule) { - LOG.warn( - "{} is annotated as a LightPIT Module but does not extend {}.", - reg.getClassName(), - AbstractLightPITServlet.class.getSimpleName() - ); - } - - if (lpservlet && lpmodule) { - final Class clazz = scclass; - final LightPITModule moduleInfo = clazz.getAnnotation(LightPITModule.class); - return Optional.of(moduleInfo); - } else { - return Optional.empty(); - } - } catch (ClassNotFoundException ex) { - LOG.error( - "Servlet registration refers to class {} which cannot be found by the class loader (Reason: {})", - reg.getClassName(), - ex.getMessage() - ); - return Optional.empty(); - } - } - - private void handleServletRegistration(String name, Registration reg) { - final Optional moduleInfo = getModuleInfo(reg); - if (moduleInfo.isPresent()) { - registeredModules.put(reg.getClassName(), moduleInfo.get()); - LOG.info("Module detected: {}", name); - } else { - LOG.debug("Servlet {} is no module, skipping.", name); - } - } - - /** - * Scans for modules and reloads them all. - */ - public void reloadAll() { - registeredModules.clear(); - sc.getServletRegistrations().forEach(this::handleServletRegistration); - - // TODO: implement dependency resolver - - dirty.set(true); - LOG.info("Modules loaded."); - } - - /** - * Synchronizes module information with the database. - * - * This must be called from the {@link AbstractLightPITServlet}. - * Admittedly the call will perform the synchronization once after reload - * and be a no-op, afterwards. - * However, we since the DatabaseFacade might be loaded after the module - * manager, we must defer the synchronization to the first request - * handled by the Servlet. - * - * @param db interface to the database - */ - public void syncWithDatabase(DatabaseFacade db) { - if (dirty.compareAndSet(true, false)) { - if (db.getDataSource().isPresent()) { - try (Connection conn = db.getDataSource().get().getConnection()) { - final ModuleDao moduleDao = CoreDAOFactory.getModuleDao(db.getSQLDialect()); - moduleDao.syncRegisteredModuleClasses(conn, registeredModules.entrySet()); - } catch (SQLException ex) { - LOG.error("Unexpected SQL Exception", ex); - } - } else { - LOG.error("No datasource present. Cannot sync module information with database."); - } - } else { - LOG.trace("Module information clean - no synchronization required."); - } - } - - /** - * Unloads all found modules. - */ - public void unloadAll() { - registeredModules.clear(); - LOG.info("All modules unloaded."); - } - - /** - * Returns the main menu. - * - * @param db the interface to the database - * @return a list of menus belonging to the main menu - */ - public List getMainMenu(DatabaseFacade db) { - // TODO: user specific menu - - if (db.getDataSource().isPresent()) { - try (Connection conn = db.getDataSource().get().getConnection()) { - final ModuleDao dao = CoreDAOFactory.getModuleDao(db.getSQLDialect()); - final List modules = dao.listAll(conn); - - final List menu = modules - .stream() - .filter((mod) -> mod.isVisible()) - .collect(Collectors.mapping( - (mod) -> new Menu( - mod.getClassname(), - new ResourceKey( - registeredModules.get(mod.getClassname()).bundleBaseName(), - registeredModules.get(mod.getClassname()).menuKey()), - registeredModules.get(mod.getClassname()).modulePath()), - Collectors.toList()) - ); - return menu; - } catch (SQLException ex) { - LOG.error("Unexpected SQLException when loading the main menu", ex); - return Collections.emptyList(); - } - } else { - return Collections.emptyList(); - } - } - - /** - * Returns an unmodifiable map of all registered modules. - * - * The key is the classname of the module. - * - * @return the map of registered modules - */ - public Map getRegisteredModules() { - return Collections.unmodifiableMap(registeredModules); - } -}