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.spring.bean;
016    
017    import com.liferay.portal.kernel.bean.PortalBeanLocatorUtil;
018    import com.liferay.portal.kernel.log.Log;
019    import com.liferay.portal.kernel.log.LogFactoryUtil;
020    
021    import java.lang.reflect.Field;
022    
023    import java.util.ArrayList;
024    import java.util.IdentityHashMap;
025    import java.util.List;
026    import java.util.Map;
027    
028    import org.springframework.beans.factory.BeanFactory;
029    import org.springframework.beans.factory.NoSuchBeanDefinitionException;
030    
031    /**
032     * @author Shuyang Zhou
033     */
034    public class BeanReferenceRefreshUtil {
035    
036            public static void refresh(BeanFactory beanFactory) throws Exception {
037                    BeanRegistrations beanRegistrations = _registeredRefreshPoints.remove(
038                            beanFactory);
039    
040                    if (beanRegistrations == null) {
041                            return;
042                    }
043    
044                    beanRegistrations.refresh();
045            }
046    
047            public static void registerRefreshPoint(
048                    BeanFactory beanFactory, Object targetBean, Field field,
049                    String referencedBeanName) {
050    
051                    BeanRegistrations beanRegistrations = _registeredRefreshPoints.get(
052                            beanFactory);
053    
054                    if (beanRegistrations == null) {
055                            beanRegistrations = new BeanRegistrations(beanFactory);
056    
057                            _registeredRefreshPoints.put(beanFactory, beanRegistrations);
058                    }
059    
060                    beanRegistrations.addRefreshPoint(
061                            targetBean, field, referencedBeanName);
062            }
063    
064            public interface PACL {
065    
066                    public Object getNewReferencedBean(
067                            String referencedBeanName, BeanFactory beanFactory);
068    
069            }
070    
071            private static final Log _log = LogFactoryUtil.getLog(
072                    BeanReferenceRefreshUtil.class);
073    
074            private static final PACL _pacl = new NoPACL();
075            private static final Map<BeanFactory, BeanRegistrations>
076                    _registeredRefreshPoints = new IdentityHashMap<>();
077    
078            private static class BeanRegistrations {
079    
080                    public BeanRegistrations(BeanFactory beanFactory) {
081                            _beanFactory = beanFactory;
082                    }
083    
084                    public void addRefreshPoint(
085                            Object bean, Field field, String referencedBeanName) {
086    
087                            List<RefreshPoint> refreshPoints = _beansToRefresh.get(bean);
088    
089                            if (refreshPoints == null) {
090                                    refreshPoints = new ArrayList<>();
091    
092                                    _beansToRefresh.put(bean, refreshPoints);
093                            }
094    
095                            refreshPoints.add(new RefreshPoint(field, referencedBeanName));
096                    }
097    
098                    public void refresh() throws Exception {
099                            for (Map.Entry<Object, List<RefreshPoint>> entry :
100                                            _beansToRefresh.entrySet()) {
101    
102                                    _refresh(entry.getKey(), entry.getValue());
103                            }
104                    }
105    
106                    private void _refresh(
107                                    Object targetBean, List<RefreshPoint> refreshPoints)
108                            throws Exception {
109    
110                            for (RefreshPoint refreshPoint : refreshPoints) {
111                                    _refresh(targetBean, refreshPoint);
112                            }
113                    }
114    
115                    private void _refresh(Object targetBean, RefreshPoint refreshPoint)
116                            throws Exception {
117    
118                            Field field = refreshPoint._field;
119    
120                            Object oldReferenceBean = field.get(targetBean);
121    
122                            String referencedBeanName = refreshPoint._referencedBeanName;
123    
124                            Object newReferencedBean = _pacl.getNewReferencedBean(
125                                    referencedBeanName, _beanFactory);
126    
127                            if (oldReferenceBean == newReferencedBean) {
128                                    return;
129                            }
130    
131                            field.set(targetBean, newReferencedBean);
132    
133                            if (_log.isDebugEnabled()) {
134                                    _log.debug(
135                                            "Refreshed field " + field + " with old value " +
136                                                    oldReferenceBean + " with new value " +
137                                                            newReferencedBean + " on bean " + targetBean);
138                            }
139                    }
140    
141                    private final BeanFactory _beanFactory;
142                    private final Map<Object, List<RefreshPoint>>
143                            _beansToRefresh = new IdentityHashMap<>();
144    
145            }
146    
147            private static class NoPACL implements PACL {
148    
149                    @Override
150                    public Object getNewReferencedBean(
151                            String referencedBeanName, BeanFactory beanFactory) {
152    
153                            try {
154                                    return beanFactory.getBean(referencedBeanName);
155                            }
156                            catch (NoSuchBeanDefinitionException nsbde) {
157                                    if (_log.isInfoEnabled()) {
158                                            _log.info(
159                                                    "Bean " + referencedBeanName + " may be defined in " +
160                                                            "the portal");
161                                    }
162    
163                                    return PortalBeanLocatorUtil.locate(referencedBeanName);
164                            }
165                    }
166    
167            }
168    
169            private static class RefreshPoint {
170    
171                    public RefreshPoint(Field field, String referencedBeanName) {
172                            _field = field;
173                            _referencedBeanName = referencedBeanName;
174                    }
175    
176                    private final Field _field;
177                    private final String _referencedBeanName;
178    
179            }
180    
181    }