| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| package org.apache.felix.configurator.impl.logger; |
| |
| import org.osgi.framework.BundleContext; |
| import org.osgi.framework.ServiceReference; |
| import org.osgi.util.tracker.ServiceTracker; |
| import org.osgi.util.tracker.ServiceTrackerCustomizer; |
| |
| /** |
| * This class adds support for using a LogService |
| */ |
| public class LogServiceEnabledLogger { |
| // name of the LogService class (this is a string to not create a reference to the class) |
| private static final String LOGSERVICE_CLASS = "org.osgi.service.log.LogService"; |
| |
| // the log service to log messages to |
| protected final ServiceTracker<Object, Object> logServiceTracker; |
| |
| private volatile InternalLogger currentLogger; |
| |
| protected volatile int trackingCount = -2; |
| |
| public LogServiceEnabledLogger(final BundleContext bundleContext) { |
| // Start a tracker for the log service |
| // we only track a single log service which in reality should be enough |
| logServiceTracker = new ServiceTracker<>( bundleContext, LOGSERVICE_CLASS, new ServiceTrackerCustomizer<Object, Object>() { |
| private volatile boolean hasService = false; |
| |
| @Override |
| public Object addingService(final ServiceReference<Object> reference) { |
| if ( !hasService ) { |
| final Object logService = bundleContext.getService(reference); |
| if ( logService != null ) { |
| hasService = true; |
| final LogServiceSupport lsl = new LogServiceSupport(logService); |
| return lsl; |
| } |
| } |
| return null; |
| } |
| |
| @Override |
| public void modifiedService(final ServiceReference<Object> reference, final Object service) { |
| // nothing to do |
| } |
| |
| @Override |
| public void removedService(final ServiceReference<Object> reference, final Object service) { |
| hasService = false; |
| bundleContext.ungetService(reference); |
| } |
| } ); |
| logServiceTracker.open(); |
| } |
| |
| /** |
| * Close the logger |
| */ |
| public void close() { |
| // stop the tracker |
| logServiceTracker.close(); |
| } |
| |
| /** |
| * Method to actually emit the log message. If the LogService is available, |
| * the message will be logged through the LogService. Otherwise the message |
| * is logged to stdout (or stderr in case of LOG_ERROR level messages), |
| * |
| * @param level The log level of the messages. This corresponds to the log |
| * levels defined by the OSGi LogService. |
| * @param message The message to print |
| * @param ex The <code>Throwable</code> causing the message to be logged. |
| */ |
| public void log(final int level, final String message, final Throwable ex) { |
| getLogger().log(level, message, ex); |
| } |
| |
| private InternalLogger getLogger() { |
| if ( this.trackingCount < this.logServiceTracker.getTrackingCount() ) { |
| final Object logServiceSupport = this.logServiceTracker.getService(); |
| if ( logServiceSupport == null ) { |
| this.currentLogger = this.getDefaultLogger(); |
| } else { |
| this.currentLogger = ((LogServiceSupport)logServiceSupport).getLogger(); |
| } |
| this.trackingCount = this.logServiceTracker.getTrackingCount(); |
| } |
| return currentLogger; |
| } |
| |
| private InternalLogger getDefaultLogger() { |
| return new StdOutLogger(); |
| } |
| } |