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 = new HashMap<>();
049            private final ServiceTracker<?, LockListener> _serviceTracker;
050    
051            private class LockListenerServiceTrackerCustomizer
052                    implements ServiceTrackerCustomizer<LockListener, LockListener> {
053    
054                    @Override
055                    public LockListener addingService(
056                            ServiceReference<LockListener> serviceReference) {
057    
058                            Registry registry = RegistryUtil.getRegistry();
059    
060                            LockListener lockListener = registry.getService(serviceReference);
061    
062                            _lockListeners.put(lockListener.getClassName(), lockListener);
063    
064                            return lockListener;
065                    }
066    
067                    @Override
068                    public void modifiedService(
069                            ServiceReference<LockListener> serviceReference,
070                            LockListener lockListener) {
071                    }
072    
073                    @Override
074                    public void removedService(
075                            ServiceReference<LockListener> serviceReference,
076                            LockListener lockListener) {
077    
078                            Registry registry = RegistryUtil.getRegistry();
079    
080                            registry.ungetService(serviceReference);
081    
082                            _lockListeners.remove(lockListener);
083                    }
084    
085            }
086    
087    }