comparison: src/java/de/uapcore/lightpit/ModuleManager.java
src/java/de/uapcore/lightpit/ModuleManager.java
- changeset 6
- da61a1646eba
- child 7
- 598670d5b0b8
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| 5:131903fc16b8 | 6:da61a1646eba |
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| 1 /* | |
| 2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. | |
| 3 * | |
| 4 * Copyright 2017 Mike Becker. All rights reserved. | |
| 5 * | |
| 6 * Redistribution and use in source and binary forms, with or without | |
| 7 * modification, are permitted provided that the following conditions are met: | |
| 8 * | |
| 9 * 1. Redistributions of source code must retain the above copyright | |
| 10 * notice, this list of conditions and the following disclaimer. | |
| 11 * | |
| 12 * 2. Redistributions in binary form must reproduce the above copyright | |
| 13 * notice, this list of conditions and the following disclaimer in the | |
| 14 * documentation and/or other materials provided with the distribution. | |
| 15 * | |
| 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | |
| 17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE | |
| 20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR | |
| 21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF | |
| 22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS | |
| 23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN | |
| 24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
| 25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE | |
| 26 * POSSIBILITY OF SUCH DAMAGE. | |
| 27 * | |
| 28 */ | |
| 29 package de.uapcore.lightpit; | |
| 30 | |
| 31 import java.util.logging.Level; | |
| 32 import java.util.logging.Logger; | |
| 33 import javax.servlet.ServletContext; | |
| 34 import javax.servlet.ServletContextEvent; | |
| 35 import javax.servlet.ServletContextListener; | |
| 36 import javax.servlet.ServletRegistration; | |
| 37 import javax.servlet.annotation.WebListener; | |
| 38 | |
| 39 /** | |
| 40 * Scans registered servlets for LightPIT modules. | |
| 41 */ | |
| 42 @WebListener | |
| 43 public class ModuleManager implements ServletContextListener { | |
| 44 | |
| 45 private static final Logger LOG = Logger.getLogger(ModuleManager.class.getName()); | |
| 46 | |
| 47 /** | |
| 48 * The attribute name in the servlet context under which an instance of this class can be found. | |
| 49 */ | |
| 50 public static final String SC_ATTR_NAME = ModuleManager.class.getName(); | |
| 51 | |
| 52 private ServletContext sc; | |
| 53 | |
| 54 @Override | |
| 55 public void contextInitialized(ServletContextEvent sce) { | |
| 56 sc = sce.getServletContext(); | |
| 57 reloadAll(); | |
| 58 sc.setAttribute(SC_ATTR_NAME, this); | |
| 59 LOG.info("Module manager injected into ServletContext."); | |
| 60 } | |
| 61 | |
| 62 @Override | |
| 63 public void contextDestroyed(ServletContextEvent sce) { | |
| 64 assert sc != null && sc.equals(sce.getServletContext()); | |
| 65 sc.removeAttribute(SC_ATTR_NAME); | |
| 66 unloadAll(); | |
| 67 } | |
| 68 | |
| 69 private boolean isRegisteredAsModule(ServletRegistration sr) { | |
| 70 try { | |
| 71 final Class scclass = Class.forName(sr.getClassName()); | |
| 72 return scclass.isAnnotationPresent(LightPITModule.class); | |
| 73 } catch (ClassNotFoundException ex) { | |
| 74 LOG.log(Level.SEVERE, | |
| 75 "Servlet registration refers to a class which cannot be found by the class loader: {0}", | |
| 76 sr.getClassName()); | |
| 77 return false; | |
| 78 } | |
| 79 } | |
| 80 | |
| 81 private void handleServletRegistration(String name, ServletRegistration sr) { | |
| 82 if (isRegisteredAsModule(sr)) { | |
| 83 LOG.log(Level.CONFIG, "Module detected: {0}", name); | |
| 84 } else { | |
| 85 LOG.log(Level.FINE, "Servlet {0} is no module, skipping.", name); | |
| 86 } | |
| 87 } | |
| 88 | |
| 89 /** | |
| 90 * Scans for modules and reloads them all. | |
| 91 */ | |
| 92 public void reloadAll() { | |
| 93 sc.getServletRegistrations().forEach(this::handleServletRegistration); | |
| 94 LOG.info("Modules loaded."); | |
| 95 } | |
| 96 | |
| 97 /** | |
| 98 * Unloads all found modules. | |
| 99 */ | |
| 100 public void unloadAll() { | |
| 101 LOG.info("All modules unloaded."); | |
| 102 } | |
| 103 } |
