1.1 --- a/src/java/de/uapcore/lightpit/ModuleManager.java Sun Apr 08 16:51:15 2018 +0200
1.2 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000
1.3 @@ -1,231 +0,0 @@
1.4 -/*
1.5 - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
1.6 - *
1.7 - * Copyright 2018 Mike Becker. All rights reserved.
1.8 - *
1.9 - * Redistribution and use in source and binary forms, with or without
1.10 - * modification, are permitted provided that the following conditions are met:
1.11 - *
1.12 - * 1. Redistributions of source code must retain the above copyright
1.13 - * notice, this list of conditions and the following disclaimer.
1.14 - *
1.15 - * 2. Redistributions in binary form must reproduce the above copyright
1.16 - * notice, this list of conditions and the following disclaimer in the
1.17 - * documentation and/or other materials provided with the distribution.
1.18 - *
1.19 - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
1.20 - * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
1.21 - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
1.22 - * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
1.23 - * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
1.24 - * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
1.25 - * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
1.26 - * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
1.27 - * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
1.28 - * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
1.29 - * POSSIBILITY OF SUCH DAMAGE.
1.30 - *
1.31 - */
1.32 -package de.uapcore.lightpit;
1.33 -
1.34 -import de.uapcore.lightpit.entities.CoreDAOFactory;
1.35 -import de.uapcore.lightpit.entities.Module;
1.36 -import de.uapcore.lightpit.entities.ModuleDao;
1.37 -import java.sql.Connection;
1.38 -import java.sql.SQLException;
1.39 -import java.util.Collections;
1.40 -import java.util.HashMap;
1.41 -import java.util.List;
1.42 -import java.util.Map;
1.43 -import java.util.Optional;
1.44 -import java.util.concurrent.atomic.AtomicBoolean;
1.45 -import java.util.stream.Collectors;
1.46 -import javax.servlet.Registration;
1.47 -import javax.servlet.ServletContext;
1.48 -import javax.servlet.ServletContextEvent;
1.49 -import javax.servlet.ServletContextListener;
1.50 -import javax.servlet.annotation.WebListener;
1.51 -import org.slf4j.Logger;
1.52 -import org.slf4j.LoggerFactory;
1.53 -
1.54 -/**
1.55 - * Scans registered servlets for LightPIT modules.
1.56 - */
1.57 -@WebListener
1.58 -public final class ModuleManager implements ServletContextListener {
1.59 -
1.60 - private static final Logger LOG = LoggerFactory.getLogger(ModuleManager.class);
1.61 -
1.62 - /**
1.63 - * The attribute name in the servlet context under which an instance of this class can be found.
1.64 - */
1.65 - public static final String SC_ATTR_NAME = ModuleManager.class.getName();
1.66 - private ServletContext sc;
1.67 -
1.68 - /**
1.69 - * Maps class names to module information.
1.70 - */
1.71 - private final Map<String, LightPITModule> registeredModules = new HashMap<>();
1.72 -
1.73 - /**
1.74 - * This flag is true, when synchronization is needed.
1.75 - */
1.76 - private final AtomicBoolean dirty = new AtomicBoolean(true);
1.77 -
1.78 - @Override
1.79 - public void contextInitialized(ServletContextEvent sce) {
1.80 - sc = sce.getServletContext();
1.81 - reloadAll();
1.82 - sc.setAttribute(SC_ATTR_NAME, this);
1.83 - LOG.info("Module manager injected into ServletContext.");
1.84 - }
1.85 -
1.86 - @Override
1.87 - public void contextDestroyed(ServletContextEvent sce) {
1.88 - unloadAll();
1.89 - }
1.90 -
1.91 - private Optional<LightPITModule> getModuleInfo(Registration reg) {
1.92 - try {
1.93 - final Class scclass = Class.forName(reg.getClassName());
1.94 -
1.95 - final boolean lpservlet = AbstractLightPITServlet.class.isAssignableFrom(scclass);
1.96 - final boolean lpmodule = scclass.isAnnotationPresent(LightPITModule.class);
1.97 -
1.98 - if (lpservlet && !lpmodule) {
1.99 - LOG.warn(
1.100 - "{} is a LightPIT Servlet but is missing the module annotation.",
1.101 - reg.getClassName()
1.102 - );
1.103 - } else if (!lpservlet && lpmodule) {
1.104 - LOG.warn(
1.105 - "{} is annotated as a LightPIT Module but does not extend {}.",
1.106 - reg.getClassName(),
1.107 - AbstractLightPITServlet.class.getSimpleName()
1.108 - );
1.109 - }
1.110 -
1.111 - if (lpservlet && lpmodule) {
1.112 - final Class<? extends AbstractLightPITServlet> clazz = scclass;
1.113 - final LightPITModule moduleInfo = clazz.getAnnotation(LightPITModule.class);
1.114 - return Optional.of(moduleInfo);
1.115 - } else {
1.116 - return Optional.empty();
1.117 - }
1.118 - } catch (ClassNotFoundException ex) {
1.119 - LOG.error(
1.120 - "Servlet registration refers to class {} which cannot be found by the class loader (Reason: {})",
1.121 - reg.getClassName(),
1.122 - ex.getMessage()
1.123 - );
1.124 - return Optional.empty();
1.125 - }
1.126 - }
1.127 -
1.128 - private void handleServletRegistration(String name, Registration reg) {
1.129 - final Optional<LightPITModule> moduleInfo = getModuleInfo(reg);
1.130 - if (moduleInfo.isPresent()) {
1.131 - registeredModules.put(reg.getClassName(), moduleInfo.get());
1.132 - LOG.info("Module detected: {}", name);
1.133 - } else {
1.134 - LOG.debug("Servlet {} is no module, skipping.", name);
1.135 - }
1.136 - }
1.137 -
1.138 - /**
1.139 - * Scans for modules and reloads them all.
1.140 - */
1.141 - public void reloadAll() {
1.142 - registeredModules.clear();
1.143 - sc.getServletRegistrations().forEach(this::handleServletRegistration);
1.144 -
1.145 - // TODO: implement dependency resolver
1.146 -
1.147 - dirty.set(true);
1.148 - LOG.info("Modules loaded.");
1.149 - }
1.150 -
1.151 - /**
1.152 - * Synchronizes module information with the database.
1.153 - *
1.154 - * This must be called from the {@link AbstractLightPITServlet}.
1.155 - * Admittedly the call will perform the synchronization once after reload
1.156 - * and be a no-op, afterwards.
1.157 - * However, we since the DatabaseFacade might be loaded after the module
1.158 - * manager, we must defer the synchronization to the first request
1.159 - * handled by the Servlet.
1.160 - *
1.161 - * @param db interface to the database
1.162 - */
1.163 - public void syncWithDatabase(DatabaseFacade db) {
1.164 - if (dirty.compareAndSet(true, false)) {
1.165 - if (db.getDataSource().isPresent()) {
1.166 - try (Connection conn = db.getDataSource().get().getConnection()) {
1.167 - final ModuleDao moduleDao = CoreDAOFactory.getModuleDao(db.getSQLDialect());
1.168 - moduleDao.syncRegisteredModuleClasses(conn, registeredModules.entrySet());
1.169 - } catch (SQLException ex) {
1.170 - LOG.error("Unexpected SQL Exception", ex);
1.171 - }
1.172 - } else {
1.173 - LOG.error("No datasource present. Cannot sync module information with database.");
1.174 - }
1.175 - } else {
1.176 - LOG.trace("Module information clean - no synchronization required.");
1.177 - }
1.178 - }
1.179 -
1.180 - /**
1.181 - * Unloads all found modules.
1.182 - */
1.183 - public void unloadAll() {
1.184 - registeredModules.clear();
1.185 - LOG.info("All modules unloaded.");
1.186 - }
1.187 -
1.188 - /**
1.189 - * Returns the main menu.
1.190 - *
1.191 - * @param db the interface to the database
1.192 - * @return a list of menus belonging to the main menu
1.193 - */
1.194 - public List<Menu> getMainMenu(DatabaseFacade db) {
1.195 - // TODO: user specific menu
1.196 -
1.197 - if (db.getDataSource().isPresent()) {
1.198 - try (Connection conn = db.getDataSource().get().getConnection()) {
1.199 - final ModuleDao dao = CoreDAOFactory.getModuleDao(db.getSQLDialect());
1.200 - final List<Module> modules = dao.listAll(conn);
1.201 -
1.202 - final List<Menu> menu = modules
1.203 - .stream()
1.204 - .filter((mod) -> mod.isVisible())
1.205 - .collect(Collectors.mapping(
1.206 - (mod) -> new Menu(
1.207 - mod.getClassname(),
1.208 - new ResourceKey(
1.209 - registeredModules.get(mod.getClassname()).bundleBaseName(),
1.210 - registeredModules.get(mod.getClassname()).menuKey()),
1.211 - registeredModules.get(mod.getClassname()).modulePath()),
1.212 - Collectors.toList())
1.213 - );
1.214 - return menu;
1.215 - } catch (SQLException ex) {
1.216 - LOG.error("Unexpected SQLException when loading the main menu", ex);
1.217 - return Collections.emptyList();
1.218 - }
1.219 - } else {
1.220 - return Collections.emptyList();
1.221 - }
1.222 - }
1.223 -
1.224 - /**
1.225 - * Returns an unmodifiable map of all registered modules.
1.226 - *
1.227 - * The key is the classname of the module.
1.228 - *
1.229 - * @return the map of registered modules
1.230 - */
1.231 - public Map<String, LightPITModule> getRegisteredModules() {
1.232 - return Collections.unmodifiableMap(registeredModules);
1.233 - }
1.234 -}
