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.model;
016    
017    import com.liferay.portal.kernel.bean.ClassLoaderBeanHandler;
018    import com.liferay.portal.kernel.util.ProxyUtil;
019    import com.liferay.portal.kernel.util.ReflectionUtil;
020    import com.liferay.registry.Filter;
021    import com.liferay.registry.Registry;
022    import com.liferay.registry.RegistryUtil;
023    import com.liferay.registry.ServiceReference;
024    import com.liferay.registry.ServiceRegistration;
025    import com.liferay.registry.ServiceTracker;
026    import com.liferay.registry.ServiceTrackerCustomizer;
027    
028    import java.lang.reflect.InvocationHandler;
029    
030    import java.util.ArrayList;
031    import java.util.List;
032    import java.util.Map;
033    import java.util.concurrent.ConcurrentHashMap;
034    import java.util.concurrent.ConcurrentMap;
035    
036    /**
037     * @author Peter Fellwock
038     */
039    public class ModelListenerRegistrationUtil {
040    
041            public static <T> ModelListener<T>[] getModelListeners(Class<T> clazz) {
042                    return _instance._getModelListeners(clazz);
043            }
044    
045            public static void register(ModelListener<?> modelListener) {
046                    Class<?> clazz = modelListener.getClass();
047    
048                    _instance._register(clazz.getName(), modelListener);
049            }
050    
051            public static void unregister(ModelListener<?> modelListener) {
052                    Class<?> clazz = modelListener.getClass();
053    
054                    _instance._unregister(clazz.getName());
055            }
056    
057            private ModelListenerRegistrationUtil() {
058                    Registry registry = RegistryUtil.getRegistry();
059    
060                    Filter filter = registry.getFilter(
061                            "(objectClass=" + ModelListener.class.getName() + ")");
062    
063                    _serviceTracker = registry.trackServices(
064                            filter, new ModelListenerTrackerCustomizer());
065    
066                    _serviceTracker.open();
067            }
068    
069            private <T> ModelListener<T>[] _getModelListeners(Class<T> clazz) {
070                    List<ModelListener<?>> modelListeners = _modelListeners.get(clazz);
071    
072                    if (modelListeners == null) {
073                            modelListeners = new ArrayList<>();
074    
075                            List<ModelListener<?>> previousModelListeners =
076                                    _modelListeners.putIfAbsent(clazz, modelListeners);
077    
078                            if (previousModelListeners != null) {
079                                    modelListeners = previousModelListeners;
080                            }
081                    }
082    
083                    return modelListeners.toArray(new ModelListener[modelListeners.size()]);
084            }
085    
086            private <T> void _register(
087                    String className, ModelListener<T> modelListener) {
088    
089                    Registry registry = RegistryUtil.getRegistry();
090    
091                    ServiceRegistration<?> serviceRegistration = registry.registerService(
092                            ModelListener.class.getName(), modelListener);
093    
094                    _serviceRegistrations.put(className, serviceRegistration);
095            }
096    
097            private void _unregister(String className) {
098                    ServiceRegistration<?> serviceRegistration =
099                            _serviceRegistrations.remove(className);
100    
101                    if (serviceRegistration != null) {
102                            serviceRegistration.unregister();
103                    }
104            }
105    
106            private static final ModelListenerRegistrationUtil _instance =
107                    new ModelListenerRegistrationUtil();
108    
109            private final ConcurrentMap<Class<?>, List<ModelListener<?>>>
110                    _modelListeners = new ConcurrentHashMap<>();
111            private final Map<String, ServiceRegistration<?>> _serviceRegistrations =
112                    new ConcurrentHashMap<>();
113            private final ServiceTracker<ModelListener<?>, ModelListener<?>>
114                    _serviceTracker;
115    
116            private class ModelListenerTrackerCustomizer
117                    implements
118                            ServiceTrackerCustomizer<ModelListener<?>, ModelListener<?>> {
119    
120                    @Override
121                    public ModelListener<?> addingService(
122                            ServiceReference<ModelListener<?>> serviceReference) {
123    
124                            Registry registry = RegistryUtil.getRegistry();
125    
126                            ModelListener<?> modelListener = registry.getService(
127                                    serviceReference);
128    
129                            Class<?> modelClass = _getModelClass(modelListener);
130    
131                            if (modelClass == null) {
132                                    return null;
133                            }
134    
135                            List<ModelListener<?>> modelListeners = _modelListeners.get(
136                                    modelClass);
137    
138                            if (modelListeners == null) {
139                                    modelListeners = new ArrayList<>();
140    
141                                    List<ModelListener<?>> previousModelListeners =
142                                            _modelListeners.putIfAbsent(modelClass, modelListeners);
143    
144                                    if (previousModelListeners != null) {
145                                            modelListeners = previousModelListeners;
146                                    }
147                            }
148    
149                            modelListeners.add(modelListener);
150    
151                            return modelListener;
152                    }
153    
154                    @Override
155                    public void modifiedService(
156                            ServiceReference<ModelListener<?>> serviceReference,
157                            ModelListener<?> modelListener) {
158                    }
159    
160                    @Override
161                    public void removedService(
162                            ServiceReference<ModelListener<?>> serviceReference,
163                            ModelListener<?> modelListener) {
164    
165                            Registry registry = RegistryUtil.getRegistry();
166    
167                            registry.ungetService(serviceReference);
168    
169                            Class<?> modelClass = _getModelClass(modelListener);
170    
171                            List<ModelListener<?>> modelListeners = _modelListeners.get(
172                                    modelClass);
173    
174                            if (modelListeners != null) {
175                                    modelListeners.remove(modelListener);
176                            }
177                    }
178    
179                    private Class<?> _getModelClass(ModelListener<?> modelListener) {
180                            Class<?> clazz = modelListener.getClass();
181    
182                            if (ProxyUtil.isProxyClass(clazz)) {
183                                    InvocationHandler invocationHandler =
184                                            ProxyUtil.getInvocationHandler(modelListener);
185    
186                                    if (invocationHandler instanceof ClassLoaderBeanHandler) {
187                                            ClassLoaderBeanHandler classLoaderBeanHandler =
188                                                    (ClassLoaderBeanHandler)invocationHandler;
189    
190                                            Object bean = classLoaderBeanHandler.getBean();
191    
192                                            clazz = bean.getClass();
193                                    }
194                            }
195    
196                            return ReflectionUtil.getGenericSuperType(clazz);
197                    }
198    
199            }
200    
201    }