001    /**
002     * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
003     *
004     * This library is free software; you can redistribute it and/or modify it under
005     * the terms of the GNU Lesser General Public License as published by the Free
006     * Software Foundation; either version 2.1 of the License, or (at your option)
007     * any later version.
008     *
009     * This library is distributed in the hope that it will be useful, but WITHOUT
010     * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
011     * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
012     * details.
013     */
014    
015    package com.liferay.portal.kernel.lock;
016    
017    import com.liferay.registry.Registry;
018    import com.liferay.registry.RegistryUtil;
019    import com.liferay.registry.ServiceReference;
020    import com.liferay.registry.ServiceTracker;
021    import com.liferay.registry.ServiceTrackerCustomizer;
022    
023    import java.util.HashMap;
024    import java.util.Map;
025    
026    /**
027     * @author Alexander Chow
028     * @author Peter Fellwock
029     */
030    public class LockListenerRegistryUtil {
031    
032            public static LockListener getLockListener(String className) {
033                    return _instance._lockListeners.get(className);
034            }
035    
036            private LockListenerRegistryUtil() {
037                    Registry registry = RegistryUtil.getRegistry();
038    
039                    _serviceTracker = registry.trackServices(
040                            LockListener.class, new LockListenerServiceTrackerCustomizer());
041    
042                    _serviceTracker.open();
043            }
044    
045            private static final LockListenerRegistryUtil _instance =
046                    new LockListenerRegistryUtil();
047    
048            private final Map<String, LockListener> _lockListeners =
049                    new HashMap<String, LockListener>();
050            private final ServiceTracker<?, LockListener> _serviceTracker;
051    
052            private class LockListenerServiceTrackerCustomizer
053                    implements ServiceTrackerCustomizer<LockListener, LockListener> {
054    
055                    @Override
056                    public LockListener addingService(
057                            ServiceReference<LockListener> serviceReference) {
058    
059                            Registry registry = RegistryUtil.getRegistry();
060    
061                            LockListener lockListener = registry.getService(serviceReference);
062    
063                            _lockListeners.put(lockListener.getClassName(), lockListener);
064    
065                            return lockListener;
066                    }
067    
068                    @Override
069                    public void modifiedService(
070                            ServiceReference<LockListener> serviceReference,
071                            LockListener lockListener) {
072                    }
073    
074                    @Override
075                    public void removedService(
076                            ServiceReference<LockListener> serviceReference,
077                            LockListener lockListener) {
078    
079                            Registry registry = RegistryUtil.getRegistry();
080    
081                            registry.ungetService(serviceReference);
082    
083                            _lockListeners.remove(lockListener);
084                    }
085    
086            }
087    
088    }