    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    }