src/main/java/de/uapcore/lightpit/ModuleManager.java

Wed, 13 May 2020 21:10:23 +0200

author
Mike Becker <universe@uap-core.de>
date
Wed, 13 May 2020 21:10:23 +0200
changeset 45
cc7f082c5ef3
parent 36
0f4f8f255c32
child 57
1262b5433644
permissions
-rw-r--r--

simplifies menu generation, adds submenus and removes VersionsModule (versions will be part of the ProjectsModule)

universe@6 1 /*
universe@6 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
universe@34 3 *
universe@24 4 * Copyright 2018 Mike Becker. All rights reserved.
universe@34 5 *
universe@6 6 * Redistribution and use in source and binary forms, with or without
universe@6 7 * modification, are permitted provided that the following conditions are met:
universe@6 8 *
universe@6 9 * 1. Redistributions of source code must retain the above copyright
universe@6 10 * notice, this list of conditions and the following disclaimer.
universe@6 11 *
universe@6 12 * 2. Redistributions in binary form must reproduce the above copyright
universe@6 13 * notice, this list of conditions and the following disclaimer in the
universe@6 14 * documentation and/or other materials provided with the distribution.
universe@6 15 *
universe@6 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
universe@6 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
universe@6 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
universe@6 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
universe@6 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
universe@6 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
universe@6 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
universe@6 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
universe@6 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
universe@6 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
universe@6 26 * POSSIBILITY OF SUCH DAMAGE.
universe@34 27 *
universe@6 28 */
universe@6 29 package de.uapcore.lightpit;
universe@6 30
universe@30 31 import org.slf4j.Logger;
universe@30 32 import org.slf4j.LoggerFactory;
universe@30 33
universe@7 34 import javax.servlet.Registration;
universe@6 35 import javax.servlet.ServletContext;
universe@6 36 import javax.servlet.ServletContextEvent;
universe@6 37 import javax.servlet.ServletContextListener;
universe@6 38 import javax.servlet.annotation.WebListener;
universe@45 39 import java.util.ArrayList;
universe@45 40 import java.util.Collections;
universe@45 41 import java.util.List;
universe@45 42 import java.util.Optional;
universe@6 43
universe@6 44 /**
universe@6 45 * Scans registered servlets for LightPIT modules.
universe@6 46 */
universe@6 47 @WebListener
universe@10 48 public final class ModuleManager implements ServletContextListener {
universe@34 49
universe@8 50 private static final Logger LOG = LoggerFactory.getLogger(ModuleManager.class);
universe@34 51
universe@6 52 /**
universe@6 53 * The attribute name in the servlet context under which an instance of this class can be found.
universe@6 54 */
universe@6 55 public static final String SC_ATTR_NAME = ModuleManager.class.getName();
universe@10 56 private ServletContext sc;
universe@34 57
universe@20 58 /**
universe@27 59 * Maps class names to module information.
universe@27 60 */
universe@45 61 private final List<LightPITModule> registeredModules = new ArrayList<>();
universe@34 62
universe@27 63 /**
universe@36 64 * Contains the menu entries for the loaded modules.
universe@20 65 */
universe@36 66 private final List<MenuEntry> mainMenu = new ArrayList<>();
universe@34 67
universe@6 68 @Override
universe@6 69 public void contextInitialized(ServletContextEvent sce) {
universe@6 70 sc = sce.getServletContext();
universe@6 71 reloadAll();
universe@6 72 sc.setAttribute(SC_ATTR_NAME, this);
universe@6 73 LOG.info("Module manager injected into ServletContext.");
universe@6 74 }
universe@6 75
universe@6 76 @Override
universe@6 77 public void contextDestroyed(ServletContextEvent sce) {
universe@6 78 unloadAll();
universe@6 79 }
universe@34 80
universe@10 81 private Optional<LightPITModule> getModuleInfo(Registration reg) {
universe@6 82 try {
universe@33 83 final Class<?> scclass = Class.forName(reg.getClassName());
universe@34 84
universe@9 85 final boolean lpservlet = AbstractLightPITServlet.class.isAssignableFrom(scclass);
universe@7 86 final boolean lpmodule = scclass.isAnnotationPresent(LightPITModule.class);
universe@34 87
universe@7 88 if (lpservlet && !lpmodule) {
universe@8 89 LOG.warn(
universe@34 90 "{} is a LightPIT Servlet but is missing the module annotation.",
universe@34 91 reg.getClassName()
universe@8 92 );
universe@7 93 } else if (!lpservlet && lpmodule) {
universe@8 94 LOG.warn(
universe@34 95 "{} is annotated as a LightPIT Module but does not extend {}.",
universe@34 96 reg.getClassName(),
universe@34 97 AbstractLightPITServlet.class.getSimpleName()
universe@8 98 );
universe@7 99 }
universe@34 100
universe@10 101 if (lpservlet && lpmodule) {
universe@33 102 final LightPITModule moduleInfo = scclass.getAnnotation(LightPITModule.class);
universe@10 103 return Optional.of(moduleInfo);
universe@10 104 } else {
universe@10 105 return Optional.empty();
universe@10 106 }
universe@6 107 } catch (ClassNotFoundException ex) {
universe@8 108 LOG.error(
universe@9 109 "Servlet registration refers to class {} which cannot be found by the class loader (Reason: {})",
universe@9 110 reg.getClassName(),
universe@9 111 ex.getMessage()
universe@8 112 );
universe@10 113 return Optional.empty();
universe@34 114 }
universe@6 115 }
universe@34 116
universe@7 117 private void handleServletRegistration(String name, Registration reg) {
universe@10 118 final Optional<LightPITModule> moduleInfo = getModuleInfo(reg);
universe@20 119 if (moduleInfo.isPresent()) {
universe@45 120 registeredModules.add(moduleInfo.get());
universe@8 121 LOG.info("Module detected: {}", name);
universe@6 122 } else {
universe@8 123 LOG.debug("Servlet {} is no module, skipping.", name);
universe@6 124 }
universe@6 125 }
universe@34 126
universe@6 127 /**
universe@6 128 * Scans for modules and reloads them all.
universe@6 129 */
universe@6 130 public void reloadAll() {
universe@21 131 registeredModules.clear();
universe@6 132 sc.getServletRegistrations().forEach(this::handleServletRegistration);
universe@36 133 createMainMenu();
universe@34 134
universe@6 135 LOG.info("Modules loaded.");
universe@6 136 }
universe@30 137
universe@6 138 /**
universe@6 139 * Unloads all found modules.
universe@6 140 */
universe@6 141 public void unloadAll() {
universe@21 142 registeredModules.clear();
universe@6 143 LOG.info("All modules unloaded.");
universe@6 144 }
universe@10 145
universe@10 146 /**
universe@36 147 * Populates the main menu based on the registered modules.
universe@10 148 */
universe@36 149 private void createMainMenu() {
universe@36 150 mainMenu.clear();
universe@45 151 registeredModules
universe@36 152 .stream()
universe@45 153 .filter(mod -> !mod.systemModule())
universe@36 154 .map(mod -> new MenuEntry(
universe@36 155 new ResourceKey(
universe@45 156 mod.bundleBaseName(),
universe@45 157 mod.menuKey()),
universe@45 158 mod.modulePath(),
universe@45 159 mod.defaultPriority()))
universe@36 160 .sorted()
universe@36 161 .forEachOrdered(mainMenu::add);
universe@10 162 }
universe@34 163
universe@21 164 /**
universe@36 165 * Returns the main menu.
universe@34 166 *
universe@36 167 * @return a list of menu items
universe@21 168 */
universe@36 169 public List<MenuEntry> getMainMenu() {
universe@36 170 return Collections.unmodifiableList(mainMenu);
universe@21 171 }
universe@6 172 }

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