| // Copyright 2006, 2007, 2008, 2010 The Apache Software Foundation |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package org.apache.tapestry5.ioc.internal.services; |
| |
| import org.apache.tapestry5.ioc.internal.util.CollectionFactory; |
| import org.apache.tapestry5.ioc.services.ClassPropertyAdapter; |
| import org.apache.tapestry5.ioc.services.PropertyAccess; |
| |
| import java.beans.BeanInfo; |
| import java.beans.IntrospectionException; |
| import java.beans.Introspector; |
| import java.beans.PropertyDescriptor; |
| import java.lang.reflect.Method; |
| import java.lang.reflect.Modifier; |
| import java.util.Arrays; |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.Map; |
| |
| @SuppressWarnings("unchecked") |
| public class PropertyAccessImpl implements PropertyAccess |
| { |
| private final Map<Class, ClassPropertyAdapter> adapters = CollectionFactory.newConcurrentMap(); |
| |
| public Object get(Object instance, String propertyName) |
| { |
| return getAdapter(instance).get(instance, propertyName); |
| } |
| |
| public void set(Object instance, String propertyName, Object value) |
| { |
| getAdapter(instance).set(instance, propertyName, value); |
| } |
| |
| /** |
| * Clears the cache of adapters and asks the {@link Introspector} to clear its cache. |
| */ |
| public synchronized void clearCache() |
| { |
| adapters.clear(); |
| |
| Introspector.flushCaches(); |
| } |
| |
| public ClassPropertyAdapter getAdapter(Object instance) |
| { |
| return getAdapter(instance.getClass()); |
| } |
| |
| public ClassPropertyAdapter getAdapter(Class forClass) |
| { |
| ClassPropertyAdapter result = adapters.get(forClass); |
| |
| if (result == null) |
| { |
| result = buildAdapter(forClass); |
| adapters.put(forClass, result); |
| } |
| |
| return result; |
| } |
| |
| /** |
| * Builds a new adapter and updates the _adapters cache. This not only guards access to the adapter cache, but also |
| * serializes access to the Java Beans Introspector, which is not thread safe. In addition, handles the case where |
| * the class in question is an interface, accumulating properties inherited from super-classes. |
| */ |
| private synchronized ClassPropertyAdapter buildAdapter(Class forClass) |
| { |
| // In some race conditions, we may hit this method for the same class multiple times. |
| // We just let it happen, replacing the old ClassPropertyAdapter with a new one. |
| |
| try |
| { |
| BeanInfo info = Introspector.getBeanInfo(forClass); |
| |
| List<PropertyDescriptor> descriptors = CollectionFactory.newList(); |
| |
| addAll(descriptors, info.getPropertyDescriptors()); |
| |
| // TAP5-921 - Introspector misses interface methods not implemented in an abstract class |
| if (forClass.isInterface() || Modifier.isAbstract(forClass.getModifiers()) ) |
| addPropertiesFromExtendedInterfaces(forClass, descriptors); |
| |
| addPropertiesFromScala(forClass, descriptors); |
| |
| return new ClassPropertyAdapterImpl(forClass, descriptors); |
| } |
| catch (Throwable ex) |
| { |
| throw new RuntimeException(ex); |
| } |
| } |
| |
| private <T> void addAll(List<T> list, T[] array) |
| { |
| list.addAll(Arrays.asList(array)); |
| } |
| |
| private void addPropertiesFromExtendedInterfaces(Class forClass, List<PropertyDescriptor> descriptors) |
| throws IntrospectionException |
| { |
| LinkedList<Class> queue = CollectionFactory.newLinkedList(); |
| |
| // Seed the queue |
| addAll(queue, forClass.getInterfaces()); |
| |
| while (!queue.isEmpty()) |
| { |
| Class c = queue.removeFirst(); |
| |
| BeanInfo info = Introspector.getBeanInfo(c); |
| |
| // Duplicates occur and are filtered out in ClassPropertyAdapter which stores |
| // a property name to descriptor map. |
| addAll(descriptors, info.getPropertyDescriptors()); |
| addAll(queue, c.getInterfaces()); |
| } |
| } |
| |
| private void addPropertiesFromScala(Class forClass, List<PropertyDescriptor> descriptors) |
| throws IntrospectionException |
| { |
| for (Method method : forClass.getMethods()) |
| { |
| addPropertyIfScalaGetterMethod(forClass, descriptors, method); |
| } |
| } |
| |
| private void addPropertyIfScalaGetterMethod(Class forClass, List<PropertyDescriptor> descriptors, Method method) |
| throws IntrospectionException |
| { |
| if (!isScalaGetterMethod(method)) |
| return; |
| |
| PropertyDescriptor propertyDescriptor = new PropertyDescriptor(method.getName(), forClass, method.getName(), |
| null); |
| |
| // found a getter, looking for the setter now |
| try |
| { |
| Method setterMethod = findScalaSetterMethod(forClass, method); |
| |
| propertyDescriptor.setWriteMethod(setterMethod); |
| } |
| catch (NoSuchMethodException e) |
| { |
| // ignore |
| } |
| |
| // check if the same property was already discovered with java bean accessors |
| |
| addScalaPropertyIfNoJavaBeansProperty(descriptors, propertyDescriptor, method); |
| } |
| |
| private void addScalaPropertyIfNoJavaBeansProperty(List<PropertyDescriptor> descriptors, |
| PropertyDescriptor propertyDescriptor, Method getterMethod) |
| { |
| boolean found = false; |
| |
| for (PropertyDescriptor currentPropertyDescriptor : descriptors) |
| { |
| if (currentPropertyDescriptor.getName().equals(getterMethod.getName())) |
| { |
| found = true; |
| |
| break; |
| } |
| } |
| |
| if (!found) |
| descriptors.add(propertyDescriptor); |
| } |
| |
| private Method findScalaSetterMethod(Class forClass, Method getterMethod) throws NoSuchMethodException |
| { |
| return forClass.getMethod(getterMethod.getName() + "_$eq", getterMethod.getReturnType()); |
| } |
| |
| private boolean isScalaGetterMethod(Method method) |
| { |
| try |
| { |
| return Modifier.isPublic(method.getModifiers()) && method.getParameterTypes().length == 0 |
| && !method.getReturnType().equals(Void.TYPE) |
| && method.getDeclaringClass().getDeclaredField(method.getName()) != null; |
| } |
| catch (NoSuchFieldException ex) |
| { |
| return false; |
| } |
| } |
| } |