001    package org.apache.turbine.services;
002    
003    
004    /*
005     * Licensed to the Apache Software Foundation (ASF) under one
006     * or more contributor license agreements.  See the NOTICE file
007     * distributed with this work for additional information
008     * regarding copyright ownership.  The ASF licenses this file
009     * to you under the Apache License, Version 2.0 (the
010     * "License"); you may not use this file except in compliance
011     * with the License.  You may obtain a copy of the License at
012     *
013     *   http://www.apache.org/licenses/LICENSE-2.0
014     *
015     * Unless required by applicable law or agreed to in writing,
016     * software distributed under the License is distributed on an
017     * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
018     * KIND, either express or implied.  See the License for the
019     * specific language governing permissions and limitations
020     * under the License.
021     */
022    
023    
024    /**
025     * This is a singleton utility class that acts as a Services broker.
026     *
027     * @author <a href="mailto:greg@shwoop.com">Greg Ritter</a>
028     * @author <a href="mailto:bmclaugh@algx.net">Brett McLaughlin</a>
029     * @author <a href="mailto:burton@apache.org">Kevin Burton</a>
030     * @author <a href="mailto:krzewski@e-point.pl">Rafal Krzewski</a>
031     * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
032     * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
033     * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
034     * @version $Id: TurbineServices.java 615328 2008-01-25 20:25:05Z tv $
035     */
036    public class TurbineServices
037            extends BaseServiceBroker
038            implements ServiceManager
039    {
040        /** The single instance of this class. */
041        private static ServiceManager instance = new TurbineServices();
042    
043        /**
044         * This constructor is protected to force clients to use
045         * getInstance() to access this class.
046         */
047        protected TurbineServices()
048        {
049            super();
050        }
051    
052        /**
053         * The method through which this class is accessed as a broker.
054         *
055         * @return The single instance of this class.
056         */
057        public static ServiceManager getInstance()
058        {
059            return instance;
060        }
061    
062        /**
063         * The method through which to change the default manager.
064         * Note that services of the previous manager will be shutdown.
065         * @param manager a new service manager.
066         */
067        public static synchronized void setManager(ServiceManager manager)
068        {
069            ServiceManager previous = instance;
070            instance = manager;
071            if (previous != null)
072            {
073                previous.shutdownServices();
074            }
075        }
076    }