001 /*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017
018 package org.apache.logging.log4j.core.osgi;
019
020 import java.util.concurrent.atomic.AtomicReference;
021
022 import org.apache.logging.log4j.Logger;
023 import org.apache.logging.log4j.core.config.plugins.util.PluginRegistry;
024 import org.apache.logging.log4j.core.util.Constants;
025 import org.apache.logging.log4j.status.StatusLogger;
026 import org.apache.logging.log4j.util.PropertiesUtil;
027 import org.osgi.framework.Bundle;
028 import org.osgi.framework.BundleActivator;
029 import org.osgi.framework.BundleContext;
030 import org.osgi.framework.BundleEvent;
031 import org.osgi.framework.SynchronousBundleListener;
032 import org.osgi.framework.wiring.BundleWiring;
033
034 /**
035 * OSGi BundleActivator.
036 */
037 public final class Activator implements BundleActivator, SynchronousBundleListener {
038
039 private static final Logger LOGGER = StatusLogger.getLogger();
040
041 private final AtomicReference<BundleContext> context = new AtomicReference<BundleContext>();
042
043 @Override
044 public void start(final BundleContext context) throws Exception {
045 // allow the user to override the default ContextSelector (e.g., by using BasicContextSelector for a global cfg)
046 if (PropertiesUtil.getProperties().getStringProperty(Constants.LOG4J_CONTEXT_SELECTOR) == null) {
047 System.setProperty(Constants.LOG4J_CONTEXT_SELECTOR, BundleContextSelector.class.getName());
048 }
049 if (this.context.compareAndSet(null, context)) {
050 context.addBundleListener(this);
051 // done after the BundleListener as to not miss any new bundle installs in the interim
052 scanInstalledBundlesForPlugins(context);
053 }
054 }
055
056 private static void scanInstalledBundlesForPlugins(final BundleContext context) {
057 final Bundle[] bundles = context.getBundles();
058 for (final Bundle bundle : bundles) {
059 if (bundle.getState() == Bundle.ACTIVE) {
060 // TODO: bundle state can change during this
061 scanBundleForPlugins(bundle);
062 }
063 }
064 }
065
066 private static void scanBundleForPlugins(final Bundle bundle) {
067 LOGGER.trace("Scanning bundle [{}] for plugins.", bundle.getSymbolicName());
068 PluginRegistry.getInstance().loadFromBundle(bundle.getBundleId(),
069 bundle.adapt(BundleWiring.class).getClassLoader());
070 }
071
072 private static void stopBundlePlugins(final Bundle bundle) {
073 LOGGER.trace("Stopping bundle [{}] plugins.", bundle.getSymbolicName());
074 // TODO: plugin lifecycle code
075 PluginRegistry.getInstance().clearBundlePlugins(bundle.getBundleId());
076 }
077
078 @Override
079 public void stop(final BundleContext context) throws Exception {
080 // not much can be done that isn't already automated by the framework
081 this.context.compareAndSet(context, null);
082 // TODO: shut down log4j
083 }
084
085 @Override
086 public void bundleChanged(final BundleEvent event) {
087 switch (event.getType()) {
088 // FIXME: STARTING instead of STARTED?
089 case BundleEvent.STARTED:
090 scanBundleForPlugins(event.getBundle());
091 break;
092
093 case BundleEvent.STOPPING:
094 stopBundlePlugins(event.getBundle());
095 break;
096
097 default:
098 break;
099 }
100 }
101 }