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 package org.apache.logging.log4j.core.osgi;
018
019 import java.lang.ref.WeakReference;
020 import java.net.URI;
021 import java.util.concurrent.atomic.AtomicReference;
022
023 import org.apache.logging.log4j.core.LoggerContext;
024 import org.apache.logging.log4j.core.impl.ContextAnchor;
025 import org.apache.logging.log4j.core.selector.ClassLoaderContextSelector;
026 import org.apache.logging.log4j.core.selector.ContextSelector;
027 import org.apache.logging.log4j.core.util.Assert;
028 import org.apache.logging.log4j.util.ReflectionUtil;
029 import org.osgi.framework.Bundle;
030 import org.osgi.framework.BundleReference;
031 import org.osgi.framework.FrameworkUtil;
032
033 /**
034 * ContextSelector for OSGi bundles. This ContextSelector works rather similarly to the
035 * {@link ClassLoaderContextSelector}, but instead of each ClassLoader having its own LoggerContext (like in a
036 * servlet container), each OSGi bundle has its own LoggerContext.
037 *
038 * @since 2.1
039 */
040 public class BundleContextSelector extends ClassLoaderContextSelector implements ContextSelector {
041
042 @Override
043 public LoggerContext getContext(final String fqcn, final ClassLoader loader, final boolean currentContext,
044 final URI configLocation) {
045 if (currentContext) {
046 final LoggerContext ctx = ContextAnchor.THREAD_CONTEXT.get();
047 if (ctx != null) {
048 return ctx;
049 }
050 return getDefault();
051 }
052 // it's quite possible that the provided ClassLoader may implement BundleReference which gives us a nice shortcut
053 if (loader instanceof BundleReference) {
054 return locateContext(((BundleReference) loader).getBundle(), configLocation);
055 }
056 final Class<?> callerClass = ReflectionUtil.getCallerClass(fqcn);
057 if (callerClass != null) {
058 return locateContext(FrameworkUtil.getBundle(callerClass), configLocation);
059 }
060 final LoggerContext lc = ContextAnchor.THREAD_CONTEXT.get();
061 return lc == null ? getDefault() : lc;
062 }
063
064 private static LoggerContext locateContext(final Bundle bundle, final URI configLocation) {
065 final String name = Assert.requireNonNull(bundle, "No Bundle provided").getSymbolicName();
066 final AtomicReference<WeakReference<LoggerContext>> ref = CONTEXT_MAP.get(name);
067 if (ref == null) {
068 final LoggerContext context = new LoggerContext(name, bundle, configLocation);
069 CONTEXT_MAP.putIfAbsent(name,
070 new AtomicReference<WeakReference<LoggerContext>>(new WeakReference<LoggerContext>(context)));
071 return CONTEXT_MAP.get(name).get().get();
072 }
073 final WeakReference<LoggerContext> r = ref.get();
074 final LoggerContext ctx = r.get();
075 if (ctx == null) {
076 final LoggerContext context = new LoggerContext(name, bundle, configLocation);
077 ref.compareAndSet(r, new WeakReference<LoggerContext>(context));
078 return ref.get().get();
079 }
080 final URI oldConfigLocation = ctx.getConfigLocation();
081 if (oldConfigLocation == null && configLocation != null) {
082 LOGGER.debug("Setting bundle ({}) configuration to {}", name, configLocation);
083 ctx.setConfigLocation(configLocation);
084 } else if (oldConfigLocation != null && configLocation != null && !configLocation.equals(oldConfigLocation)) {
085 LOGGER.warn("locateContext called with URI [{}], but existing LoggerContext has URI [{}]",
086 configLocation, oldConfigLocation);
087 }
088 return ctx;
089 }
090 }