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    1   /*
    2    * Licensed to the Apache Software Foundation (ASF) under one or more
    3    * contributor license agreements. See the NOTICE file distributed with
    4    * this work for additional information regarding copyright ownership.
    5    * The ASF licenses this file to You under the Apache license, Version 2.0
    6    * (the "License"); you may not use this file except in compliance with
    7    * the License. You may obtain a copy of the License at
    8    *
    9    *      http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the license for the specific language governing permissions and
    15   * limitations under the license.
    16   */
    17  package org.apache.logging.log4j.core.osgi;
    18
    19  import java.lang.ref.WeakReference;
    20  import java.net.URI;
    21  import java.util.concurrent.atomic.AtomicReference;
    22
    23  import org.apache.logging.log4j.core.LoggerContext;
    24  import org.apache.logging.log4j.core.impl.ContextAnchor;
    25  import org.apache.logging.log4j.core.selector.ClassLoaderContextSelector;
    26  import org.apache.logging.log4j.core.selector.ContextSelector;
    27  import org.apache.logging.log4j.core.util.Assert;
    28  import org.apache.logging.log4j.util.ReflectionUtil;
    29  import org.osgi.framework.Bundle;
    30  import org.osgi.framework.BundleReference;
    31  import org.osgi.framework.FrameworkUtil;
    32
    33  /**
    34   * ContextSelector for OSGi bundles. This ContextSelector works rather similarly to the
    35   * {@link ClassLoaderContextSelector}, but instead of each ClassLoader having its own LoggerContext (like in a
    36   * servlet container), each OSGi bundle has its own LoggerContext.
    37   *
    38   * @since 2.1
    39   */
    40  public class BundleContextSelector extends ClassLoaderContextSelector implements ContextSelector {
    41
    42      @Override
    43      public LoggerContext getContext(final String fqcn, final ClassLoader loader, final boolean currentContext,
    44                                      final URI configLocation) {
    45          if (currentContext) {
    46              final LoggerContext ctx = ContextAnchor.THREAD_CONTEXT.get();
    47              if (ctx != null) {
    48                  return ctx;
    49              }
    50              return getDefault();
    51          }
    52          // it's quite possible that the provided ClassLoader may implement BundleReference which gives us a nice shortcut
    53          if (loader instanceof BundleReference) {
    54              return locateContext(((BundleReference) loader).getBundle(), configLocation);
    55          }
    56          final Class<?> callerClass = ReflectionUtil.getCallerClass(fqcn);
    57          if (callerClass != null) {
    58              return locateContext(FrameworkUtil.getBundle(callerClass), configLocation);
    59          }
    60          final LoggerContext lc = ContextAnchor.THREAD_CONTEXT.get();
    61          return lc == null ? getDefault() : lc;
    62      }
    63
    64      private static LoggerContext locateContext(final Bundle bundle, final URI configLocation) {
    65          final String name = Assert.requireNonNull(bundle, "No Bundle provided").getSymbolicName();
    66          final AtomicReference<WeakReference<LoggerContext>> ref = CONTEXT_MAP.get(name);
    67          if (ref == null) {
    68              final LoggerContext context = new LoggerContext(name, bundle, configLocation);
    69              CONTEXT_MAP.putIfAbsent(name,
    70                  new AtomicReference<WeakReference<LoggerContext>>(new WeakReference<LoggerContext>(context)));
    71              return CONTEXT_MAP.get(name).get().get();
    72          }
    73          final WeakReference<LoggerContext> r = ref.get();
    74          final LoggerContext ctx = r.get();
    75          if (ctx == null) {
    76              final LoggerContext context = new LoggerContext(name, bundle, configLocation);
    77              ref.compareAndSet(r, new WeakReference<LoggerContext>(context));
    78              return ref.get().get();
    79          }
    80          final URI oldConfigLocation = ctx.getConfigLocation();
    81          if (oldConfigLocation == null && configLocation != null) {
    82              LOGGER.debug("Setting bundle ({}) configuration to {}", name, configLocation);
    83              ctx.setConfigLocation(configLocation);
    84          } else if (oldConfigLocation != null && configLocation != null && !configLocation.equals(oldConfigLocation)) {
    85              LOGGER.warn("locateContext called with URI [{}], but existing LoggerContext has URI [{}]",
    86                  configLocation, oldConfigLocation);
    87          }
    88          return ctx;
    89      }
    90  }