Logger.java

/**
 *  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.aries.jmx;

import org.osgi.framework.BundleContext;
import org.osgi.framework.ServiceReference;
import org.osgi.service.log.LogService;
import org.osgi.util.tracker.ServiceTracker;

/**
 * <p>This <tt>Logger</tt> class represents ServiceTracker for LogService. 
 * It provides methods for logging messages. If LogService is not available it logs to stdout.</p>
 * 
 * @see org.osgi.service.log.LogService
 * @see org.osgi.util.tracker.ServiceTracker
 * @version $Rev$ $Date$
 */
@SuppressWarnings("rawtypes")
public class Logger extends ServiceTracker implements LogService {
    
    /**
     * Constructs new Logger(ServiceTracker for LogService).
     * 
     * @param context bundle context.
     */
    @SuppressWarnings("unchecked")
	public Logger(BundleContext context) {
        super(context, LogService.class.getName(), null);
    }

    /**
     * @see org.osgi.service.log.LogService#log(int, java.lang.String)
     */
    public void log(int level, String message) {
        LogService logService = (LogService) getService();
        if (logService != null) {
            logService.log(level, message);
        }

    }

    /**
     * @see org.osgi.service.log.LogService#log(int, java.lang.String, java.lang.Throwable)
     */
    public void log(int level, String message, Throwable exception) {
        LogService logService = (LogService) getService();
        if (logService != null) {
            logService.log(level, message, exception);
        }
    }

    /**
     * @see org.osgi.service.log.LogService#log(org.osgi.framework.ServiceReference, int, java.lang.String)
     */
    public void log(ServiceReference ref, int level, String message) {
        LogService logService = (LogService) getService();
        if (logService != null) {
            logService.log(ref, level, message);
        }
    }

    /**
     * @see org.osgi.service.log.LogService#log(org.osgi.framework.ServiceReference, int, java.lang.String,
     *      java.lang.Throwable)
     */
    public void log(ServiceReference ref, int level, String message, Throwable exception) {
        LogService logService = (LogService) getService();
        if (logService != null) {
            logService.log(ref, level, message, exception);
        }
    }

}