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

Sun, 10 May 2020 10:11:37 +0200

author
Mike Becker <universe@uap-core.de>
date
Sun, 10 May 2020 10:11:37 +0200
changeset 36
0f4f8f255c32
parent 34
824d4042c857
child 45
cc7f082c5ef3
permissions
-rw-r--r--

removes features that are not (and probably will not) used anyway

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@30 39 import java.util.*;
universe@6 40
universe@6 41 /**
universe@6 42 * Scans registered servlets for LightPIT modules.
universe@6 43 */
universe@6 44 @WebListener
universe@10 45 public final class ModuleManager implements ServletContextListener {
universe@34 46
universe@8 47 private static final Logger LOG = LoggerFactory.getLogger(ModuleManager.class);
universe@34 48
universe@6 49 /**
universe@6 50 * The attribute name in the servlet context under which an instance of this class can be found.
universe@6 51 */
universe@6 52 public static final String SC_ATTR_NAME = ModuleManager.class.getName();
universe@10 53 private ServletContext sc;
universe@34 54
universe@20 55 /**
universe@27 56 * Maps class names to module information.
universe@27 57 */
universe@27 58 private final Map<String, LightPITModule> registeredModules = new HashMap<>();
universe@34 59
universe@27 60 /**
universe@36 61 * Contains the menu entries for the loaded modules.
universe@20 62 */
universe@36 63 private final List<MenuEntry> mainMenu = new ArrayList<>();
universe@34 64
universe@6 65 @Override
universe@6 66 public void contextInitialized(ServletContextEvent sce) {
universe@6 67 sc = sce.getServletContext();
universe@6 68 reloadAll();
universe@6 69 sc.setAttribute(SC_ATTR_NAME, this);
universe@6 70 LOG.info("Module manager injected into ServletContext.");
universe@6 71 }
universe@6 72
universe@6 73 @Override
universe@6 74 public void contextDestroyed(ServletContextEvent sce) {
universe@6 75 unloadAll();
universe@6 76 }
universe@34 77
universe@10 78 private Optional<LightPITModule> getModuleInfo(Registration reg) {
universe@6 79 try {
universe@33 80 final Class<?> scclass = Class.forName(reg.getClassName());
universe@34 81
universe@9 82 final boolean lpservlet = AbstractLightPITServlet.class.isAssignableFrom(scclass);
universe@7 83 final boolean lpmodule = scclass.isAnnotationPresent(LightPITModule.class);
universe@34 84
universe@7 85 if (lpservlet && !lpmodule) {
universe@8 86 LOG.warn(
universe@34 87 "{} is a LightPIT Servlet but is missing the module annotation.",
universe@34 88 reg.getClassName()
universe@8 89 );
universe@7 90 } else if (!lpservlet && lpmodule) {
universe@8 91 LOG.warn(
universe@34 92 "{} is annotated as a LightPIT Module but does not extend {}.",
universe@34 93 reg.getClassName(),
universe@34 94 AbstractLightPITServlet.class.getSimpleName()
universe@8 95 );
universe@7 96 }
universe@34 97
universe@10 98 if (lpservlet && lpmodule) {
universe@33 99 final LightPITModule moduleInfo = scclass.getAnnotation(LightPITModule.class);
universe@10 100 return Optional.of(moduleInfo);
universe@10 101 } else {
universe@10 102 return Optional.empty();
universe@10 103 }
universe@6 104 } catch (ClassNotFoundException ex) {
universe@8 105 LOG.error(
universe@9 106 "Servlet registration refers to class {} which cannot be found by the class loader (Reason: {})",
universe@9 107 reg.getClassName(),
universe@9 108 ex.getMessage()
universe@8 109 );
universe@10 110 return Optional.empty();
universe@34 111 }
universe@6 112 }
universe@34 113
universe@7 114 private void handleServletRegistration(String name, Registration reg) {
universe@10 115 final Optional<LightPITModule> moduleInfo = getModuleInfo(reg);
universe@20 116 if (moduleInfo.isPresent()) {
universe@34 117 registeredModules.put(reg.getClassName(), moduleInfo.get());
universe@8 118 LOG.info("Module detected: {}", name);
universe@6 119 } else {
universe@8 120 LOG.debug("Servlet {} is no module, skipping.", name);
universe@6 121 }
universe@6 122 }
universe@34 123
universe@6 124 /**
universe@6 125 * Scans for modules and reloads them all.
universe@6 126 */
universe@6 127 public void reloadAll() {
universe@21 128 registeredModules.clear();
universe@6 129 sc.getServletRegistrations().forEach(this::handleServletRegistration);
universe@36 130 createMainMenu();
universe@34 131
universe@6 132 LOG.info("Modules loaded.");
universe@6 133 }
universe@30 134
universe@6 135 /**
universe@6 136 * Unloads all found modules.
universe@6 137 */
universe@6 138 public void unloadAll() {
universe@21 139 registeredModules.clear();
universe@6 140 LOG.info("All modules unloaded.");
universe@6 141 }
universe@10 142
universe@10 143 /**
universe@36 144 * Populates the main menu based on the registered modules.
universe@10 145 */
universe@36 146 private void createMainMenu() {
universe@36 147 mainMenu.clear();
universe@36 148 registeredModules.entrySet()
universe@36 149 .stream()
universe@36 150 .filter(mod -> !mod.getValue().systemModule())
universe@36 151 .map(mod -> new MenuEntry(
universe@36 152 mod.getKey(),
universe@36 153 new ResourceKey(
universe@36 154 mod.getValue().bundleBaseName(),
universe@36 155 mod.getValue().menuKey()),
universe@36 156 mod.getValue().modulePath(),
universe@36 157 mod.getValue().defaultPriority()))
universe@36 158 .sorted()
universe@36 159 .forEachOrdered(mainMenu::add);
universe@10 160 }
universe@34 161
universe@21 162 /**
universe@36 163 * Returns the main menu.
universe@34 164 *
universe@36 165 * @return a list of menu items
universe@21 166 */
universe@36 167 public List<MenuEntry> getMainMenu() {
universe@36 168 return Collections.unmodifiableList(mainMenu);
universe@21 169 }
universe@6 170 }

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