--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java/de/uapcore/lightpit/ModuleManager.java Sun Nov 26 18:09:23 2017 +0100
@@ -0,0 +1,103 @@
+/*
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
+ *
+ * Copyright 2017 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 java.util.logging.Level;
+import java.util.logging.Logger;
+import javax.servlet.ServletContext;
+import javax.servlet.ServletContextEvent;
+import javax.servlet.ServletContextListener;
+import javax.servlet.ServletRegistration;
+import javax.servlet.annotation.WebListener;
+
+/**
+ * Scans registered servlets for LightPIT modules.
+ */
+@WebListener
+public class ModuleManager implements ServletContextListener {
+
+ private static final Logger LOG = Logger.getLogger(ModuleManager.class.getName());
+
+ /**
+ * 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;
+
+ @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) {
+ assert sc != null && sc.equals(sce.getServletContext());
+ sc.removeAttribute(SC_ATTR_NAME);
+ unloadAll();
+ }
+
+ private boolean isRegisteredAsModule(ServletRegistration sr) {
+ try {
+ final Class scclass = Class.forName(sr.getClassName());
+ return scclass.isAnnotationPresent(LightPITModule.class);
+ } catch (ClassNotFoundException ex) {
+ LOG.log(Level.SEVERE,
+ "Servlet registration refers to a class which cannot be found by the class loader: {0}",
+ sr.getClassName());
+ return false;
+ }
+ }
+
+ private void handleServletRegistration(String name, ServletRegistration sr) {
+ if (isRegisteredAsModule(sr)) {
+ LOG.log(Level.CONFIG, "Module detected: {0}", name);
+ } else {
+ LOG.log(Level.FINE, "Servlet {0} is no module, skipping.", name);
+ }
+ }
+
+ /**
+ * Scans for modules and reloads them all.
+ */
+ public void reloadAll() {
+ sc.getServletRegistrations().forEach(this::handleServletRegistration);
+ LOG.info("Modules loaded.");
+ }
+
+ /**
+ * Unloads all found modules.
+ */
+ public void unloadAll() {
+ LOG.info("All modules unloaded.");
+ }
+}