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