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    1   /*
    2    * Copyright 2012 The Netty Project
    3    *
    4    * The Netty Project licenses this file to you under the Apache License,
    5    * version 2.0 (the "License"); you may not use this file except in compliance
    6    * with the License. You may obtain a copy of the License at:
    7    *
    8    *   http://www.apache.org/licenses/LICENSE-2.0
    9    *
    10   * Unless required by applicable law or agreed to in writing, software
    11   * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
    12   * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
    13   * License for the specific language governing permissions and limitations
    14   * under the License.
    15   */
    16  package org.jboss.netty.logging;
    17
    18  import org.osgi.framework.BundleContext;
    19  import org.osgi.framework.ServiceReference;
    20  import org.osgi.service.log.LogService;
    21  import org.osgi.util.tracker.ServiceTracker;
    22
    23  /**
    24   * Logger factory which creates an <a href="http://www.osgi.org/">OSGi</a>
    25   * {@link LogService} logger.
    26   */
    27  public class OsgiLoggerFactory extends InternalLoggerFactory {
    28
    29      private final ServiceTracker logServiceTracker;
    30      private final InternalLoggerFactory fallback;
    31      volatile LogService logService;
    32
    33      public OsgiLoggerFactory(BundleContext ctx) {
    34          this(ctx, null);
    35      }
    36
    37      public OsgiLoggerFactory(BundleContext ctx, InternalLoggerFactory fallback) {
    38          if (ctx == null) {
    39              throw new NullPointerException("ctx");
    40          }
    41          if (fallback == null) {
    42              fallback = InternalLoggerFactory.getDefaultFactory();
    43              if (fallback instanceof OsgiLoggerFactory) {
    44                  fallback = new JdkLoggerFactory();
    45              }
    46          }
    47
    48          this.fallback = fallback;
    49          logServiceTracker = new ServiceTracker(
    50                  ctx, "org.osgi.service.log.LogService", null) {
    51                      @Override
    52                      public Object addingService(ServiceReference reference) {
    53                          LogService service = (LogService) super.addingService(reference);
    54                          logService = service;
    55                          return service;
    56                      }
    57
    58                      @Override
    59                      public void removedService(ServiceReference reference,
    60                              Object service) {
    61                          logService = null;
    62                      }
    63          };
    64          logServiceTracker.open();
    65      }
    66
    67      public InternalLoggerFactory getFallback() {
    68          return fallback;
    69      }
    70
    71      public LogService getLogService() {
    72          return logService;
    73      }
    74
    75      public void destroy() {
    76          logService = null;
    77          logServiceTracker.close();
    78      }
    79
    80      @Override
    81      public InternalLogger newInstance(String name) {
    82          return new OsgiLogger(this, name, fallback.newInstance(name));
    83      }
    84  }