001    /*
002      GRANITE DATA SERVICES
003      Copyright (C) 2011 GRANITE DATA SERVICES S.A.S.
004    
005      This file is part of Granite Data Services.
006    
007      Granite Data Services is free software; you can redistribute it and/or modify
008      it under the terms of the GNU Library General Public License as published by
009      the Free Software Foundation; either version 2 of the License, or (at your
010      option) any later version.
011    
012      Granite Data Services is distributed in the hope that it will be useful, but
013      WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
014      FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
015      for more details.
016    
017      You should have received a copy of the GNU Library General Public License
018      along with this library; if not, see <http://www.gnu.org/licenses/>.
019    */
020    
021    package org.granite.hibernate;
022    
023    import java.io.Serializable;
024    import java.lang.reflect.Field;
025    import java.lang.reflect.Method;
026    import java.lang.reflect.Type;
027    import java.util.concurrent.ConcurrentHashMap;
028    
029    import javax.persistence.EmbeddedId;
030    import javax.persistence.Id;
031    
032    import org.granite.config.GraniteConfig;
033    import org.granite.context.GraniteContext;
034    import org.granite.messaging.service.ServiceException;
035    import org.granite.util.TypeUtil;
036    import org.granite.util.Introspector;
037    import org.granite.util.PropertyDescriptor;
038    import org.hibernate.engine.SessionImplementor;
039    import org.hibernate.proxy.HibernateProxy;
040    import org.hibernate.type.AbstractComponentType;
041    
042    /**
043     * @author Franck WOLFF
044     */
045    @SuppressWarnings("deprecation")
046    public class ProxyFactory {
047    
048        private static final Class<?>[] INTERFACES = new Class[]{HibernateProxy.class};
049    
050        protected final ConcurrentHashMap<Class<?>, Object[]> identifierInfos = new ConcurrentHashMap<Class<?>, Object[]>();
051    
052        private final Method getProxyFactory;
053        private final Method getProxy;
054    
055        public ProxyFactory(String initializerClassName) {
056            try {
057                // Get proxy methods: even if CGLIB/Javassist LazyInitializer implementations share a common
058                    // superclass, getProxyFactory/getProxy methods are declared as static in each inherited
059                    // class with the same signature.
060                Class<?> initializerClass = TypeUtil.forName(initializerClassName);
061                getProxyFactory = initializerClass.getMethod("getProxyFactory", new Class[]{Class.class, Class[].class});
062                            Class<?> componentTypeClass = AbstractComponentType.class;
063                try {
064                    // Hibernate 3.6
065                    componentTypeClass = TypeUtil.forName("org.hibernate.type.CompositeType");
066                }
067                catch (ClassNotFoundException e) {
068                    // Hibernate until 3.5 
069                }
070                getProxy = initializerClass.getMethod("getProxy", new Class[]{
071                    Class.class, String.class, Class.class, Class[].class, Method.class, Method.class,
072                    componentTypeClass, Serializable.class, SessionImplementor.class
073                });
074            } 
075            catch (Exception e) {
076                throw new ServiceException("Could not introspect initializer class: " + initializerClassName, e);
077            }
078        }
079    
080        public HibernateProxy getProxyInstance(String persistentClassName, String entityName, Serializable id) {
081            try {
082                // Get ProxyFactory.
083                Class<?> persistentClass = TypeUtil.forName(persistentClassName);
084                Class<?> factory = (Class<?>)getProxyFactory.invoke(null, new Object[]{persistentClass, INTERFACES});
085    
086                // Convert id (if necessary).
087                Object[] identifierInfo = getIdentifierInfo(persistentClass);
088                Type identifierType = (Type)identifierInfo[0];
089                Method identifierGetter = (Method)identifierInfo[1];
090                if (id == null || !identifierType.equals(id.getClass())) {
091                    GraniteConfig config = GraniteContext.getCurrentInstance().getGraniteConfig();
092                    id = (Serializable)config.getConverters().convert(id, identifierType);
093                }
094    
095                // Get Proxy
096                return (HibernateProxy)getProxy.invoke(null, new Object[]{factory, entityName, persistentClass, INTERFACES, identifierGetter, null, null, id, null});
097            } 
098            catch (Exception e) {
099                throw new ServiceException("Error with proxy description: " + persistentClassName + '/' + entityName + " and id: " + id, e);
100            }
101        }
102    
103        protected Object[] getIdentifierInfo(Class<?> persistentClass) {
104    
105            Object[] info = identifierInfos.get(persistentClass);
106            if (info != null)
107                return info;
108    
109            Type type = null;
110            Method getter = null;
111            for (Class<?> clazz = persistentClass; clazz != Object.class && clazz != null; clazz = clazz.getSuperclass()) {
112                for (Field field : clazz.getDeclaredFields()) {
113                    if (field.isAnnotationPresent(Id.class) || field.isAnnotationPresent(EmbeddedId.class)) {
114                        type = field.getGenericType();
115                        break;
116                    }
117                }
118            }
119    
120            if (type == null) {
121                PropertyDescriptor[] propertyDescriptors = Introspector.getPropertyDescriptors(persistentClass);
122    
123                for (PropertyDescriptor propertyDescriptor : propertyDescriptors) {
124                    Method method = propertyDescriptor.getReadMethod();
125                    if (method != null && (
126                            method.isAnnotationPresent(Id.class) ||
127                            method.isAnnotationPresent(EmbeddedId.class))) {
128                        type = method.getGenericReturnType();
129                        getter = method;
130                        break;
131                    }
132                    method = propertyDescriptor.getWriteMethod();
133                    if (method != null && (
134                            method.isAnnotationPresent(Id.class) ||
135                            method.isAnnotationPresent(EmbeddedId.class))) {
136                        type = method.getGenericParameterTypes()[0];
137                        break;
138                    }
139                }
140            }
141    
142            if (type != null) {
143                    info = new Object[] { type, getter };
144                Object[] previousInfo = identifierInfos.putIfAbsent(persistentClass, info);
145                if (previousInfo != null)
146                    info = previousInfo; // should be the same...
147                return info;
148            }
149    
150            throw new IllegalArgumentException("Could not find id in: " + persistentClass);
151        }
152    }