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.portlet.exportimport.xstream;
016    
017    import com.liferay.registry.Registry;
018    import com.liferay.registry.RegistryUtil;
019    import com.liferay.registry.ServiceReference;
020    import com.liferay.registry.ServiceRegistration;
021    import com.liferay.registry.ServiceTracker;
022    import com.liferay.registry.ServiceTrackerCustomizer;
023    import com.liferay.registry.collections.ServiceRegistrationMap;
024    import com.liferay.registry.collections.ServiceRegistrationMapImpl;
025    
026    import java.util.HashSet;
027    import java.util.Set;
028    
029    /**
030     * @author Daniel Kocsis
031     */
032    public class XStreamConverterRegistryUtil {
033    
034            public static Set<XStreamConverter> getXStreamConverters() {
035                    return _instance._getXStreamConverters();
036            }
037    
038            public static void register(XStreamConverter xStreamConverter) {
039                    _instance._register(xStreamConverter);
040            }
041    
042            public static void unregister(XStreamConverter xStreamConverter) {
043                    _instance._unregister(xStreamConverter);
044            }
045    
046            private XStreamConverterRegistryUtil() {
047                    Registry registry = RegistryUtil.getRegistry();
048    
049                    _serviceTracker = registry.trackServices(
050                            XStreamConverter.class,
051                            new XStreamConverterServiceTrackerCustomizer());
052    
053                    _serviceTracker.open();
054            }
055    
056            private Set<XStreamConverter> _getXStreamConverters() {
057                    return _xStreamConverters;
058            }
059    
060            private void _register(XStreamConverter xStreamConverter) {
061                    Registry registry = RegistryUtil.getRegistry();
062    
063                    ServiceRegistration<XStreamConverter> serviceRegistration =
064                            registry.registerService(XStreamConverter.class, xStreamConverter);
065    
066                    _serviceRegistrations.put(xStreamConverter, serviceRegistration);
067            }
068    
069            private void _unregister(XStreamConverter xStreamConverter) {
070                    ServiceRegistration<XStreamConverter> serviceRegistration =
071                            _serviceRegistrations.remove(xStreamConverter);
072    
073                    if (serviceRegistration != null) {
074                            serviceRegistration.unregister();
075                    }
076            }
077    
078            private static final XStreamConverterRegistryUtil _instance =
079                    new XStreamConverterRegistryUtil();
080    
081            private final ServiceRegistrationMap<XStreamConverter>
082                    _serviceRegistrations = new ServiceRegistrationMapImpl<>();
083            private final ServiceTracker <XStreamConverter, XStreamConverter>
084                    _serviceTracker;
085            private final Set<XStreamConverter> _xStreamConverters = new HashSet<>();
086    
087            private class XStreamConverterServiceTrackerCustomizer
088                    implements ServiceTrackerCustomizer
089                            <XStreamConverter, XStreamConverter> {
090    
091                    @Override
092                    public XStreamConverter addingService(
093                            ServiceReference<XStreamConverter> serviceReference) {
094    
095                            Registry registry = RegistryUtil.getRegistry();
096    
097                            XStreamConverter xStreamConverter = registry.getService(
098                                    serviceReference);
099    
100                            _xStreamConverters.add(xStreamConverter);
101    
102                            return xStreamConverter;
103                    }
104    
105                    @Override
106                    public void modifiedService(
107                            ServiceReference<XStreamConverter> serviceReference,
108                            XStreamConverter xStreamConverter) {
109                    }
110    
111                    @Override
112                    public void removedService(
113                            ServiceReference<XStreamConverter> serviceReference,
114                            XStreamConverter xStreamConverter) {
115    
116                            Registry registry = RegistryUtil.getRegistry();
117    
118                            registry.ungetService(serviceReference);
119    
120                            _xStreamConverters.remove(xStreamConverter);
121                    }
122    
123            }
124    
125    }