/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.sling.adapter.internal;
import static org.apache.sling.api.adapter.AdapterFactory.ADAPTABLE_CLASSES;
import static org.apache.sling.api.adapter.AdapterFactory.ADAPTER_CLASSES;
import java.util.ArrayList;
import java.util.Dictionary;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Properties;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.Reference;
import org.apache.felix.scr.annotations.ReferenceCardinality;
import org.apache.felix.scr.annotations.ReferencePolicy;
import org.apache.felix.scr.annotations.Service;
import org.apache.sling.api.SlingConstants;
import org.apache.sling.api.adapter.AdapterFactory;
import org.apache.sling.api.adapter.AdapterManager;
import org.apache.sling.api.resource.SyntheticResource;
import org.apache.sling.commons.osgi.PropertiesUtil;
import org.osgi.framework.Constants;
import org.osgi.framework.ServiceReference;
import org.osgi.service.component.ComponentContext;
import org.osgi.service.event.Event;
import org.osgi.service.event.EventAdmin;
import org.osgi.service.packageadmin.PackageAdmin;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* The <code>AdapterManagerImpl</code> class implements the
* {@link AdapterManager} interface and is registered as a service for that
* interface to be used by any clients.
*
*/
@Component(immediate=true)
@Service
@Properties({
@Property(name=Constants.SERVICE_DESCRIPTION, value="Sling Adapter Manager"),
@Property(name=Constants.SERVICE_VENDOR, value="The Apache Software Foundation")
})
@Reference(name="AdapterFactory", referenceInterface=AdapterFactory.class,
cardinality=ReferenceCardinality.OPTIONAL_MULTIPLE, policy=ReferencePolicy.DYNAMIC)
public class AdapterManagerImpl implements AdapterManager {
private final Logger log = LoggerFactory.getLogger(getClass());
/**
* The OSGi <code>ComponentContext</code> to retrieve
* {@link AdapterFactory} service instances.
*/
private volatile ComponentContext context;
/**
* A list of {@link AdapterFactory} services bound to this manager before
* the manager has been activated. These bound services will be accessed as
* soon as the manager is being activated.
*/
private final List<ServiceReference> boundAdapterFactories = new LinkedList<ServiceReference>();
/**
* A map of {@link AdapterFactoryDescriptorMap} instances. The map is
* indexed by the fully qualified class names listed in the
* {@link AdapterFactory#ADAPTABLE_CLASSES} property of the
* {@link AdapterFactory} services.
*
* @see AdapterFactoryDescriptorMap
*/
private final Map<String, AdapterFactoryDescriptorMap> descriptors = new HashMap<String, AdapterFactoryDescriptorMap>();
/**
* Matrix of {@link AdapterFactoryDescriptor} instances primarily indexed by the fully
* qualified name of the class to be adapted and secondarily indexed by the
* fully qualified name of the class to adapt to (the target class).
* <p>
* This cache is built on demand by calling the
* {@link #getAdapterFactories(Class)} method. It is cleared
* whenever an adapter factory is registered on unregistered.
*/
private final ConcurrentMap<String, Map<String, List<AdapterFactoryDescriptor>>> factoryCache
= new ConcurrentHashMap<String, Map<String, List<AdapterFactoryDescriptor>>>();
/**
* The service tracker for the event admin
*/
@Reference(cardinality=ReferenceCardinality.OPTIONAL_UNARY, policy=ReferencePolicy.DYNAMIC)
private volatile EventAdmin eventAdmin;
@Reference
private PackageAdmin packageAdmin;
// ---------- AdapterManager interface -------------------------------------
/**
* Returns the adapted <code>adaptable</code> or <code>null</code> if
* the object cannot be adapted.
*
* @see org.apache.sling.api.adapter.AdapterManager#getAdapter(java.lang.Object, java.lang.Class)
*/
public <AdapterType> AdapterType getAdapter(final Object adaptable,
final Class<AdapterType> type) {
// get the adapter factories for the type of adaptable object
final Map<String, List<AdapterFactoryDescriptor>> factories = getAdapterFactories(adaptable.getClass());
// get the factory for the target type
final List<AdapterFactoryDescriptor> descList = factories.get(type.getName());
if (descList != null && descList.size() > 0) {
for (AdapterFactoryDescriptor desc : descList) {
final AdapterFactory factory = desc == null ? null : desc.getFactory();
// have the factory adapt the adaptable if the factory exists
if (factory != null) {
log.debug("Trying adapter factory {} to map {} to {}",
new Object [] { factory, adaptable, type });
AdapterType adaptedObject = factory.getAdapter(adaptable, type);
if (adaptedObject != null) {
log.debug("Using adapter factory {} to map {} to {}",
new Object [] { factory, adaptable, type });
return adaptedObject;
}
}
}
}
// no factory has been found, so we cannot adapt
log.debug("No adapter factory found to map {} to {}", adaptable, type);
return null;
}
// ----------- SCR integration ---------------------------------------------
/**
* Activate the manager.
* Bind all already registered factories
* @param context Component context
*/
protected void activate(final ComponentContext context) {
this.context = context;
// register all adapter factories bound before activation
final List<ServiceReference> refs;
synchronized ( this.boundAdapterFactories ) {
refs = new ArrayList<ServiceReference>(this.boundAdapterFactories);
boundAdapterFactories.clear();
}
for (final ServiceReference reference : refs) {
registerAdapterFactory(context, reference);
}
// final "enable" this manager by setting the instance
SyntheticResource.setAdapterManager(this);
}
/**
* Deactivate
* @param context Not used
*/
protected void deactivate(final ComponentContext context) {
SyntheticResource.unsetAdapterManager(this);
this.context = null;
}
/**
* Bind a new adapter factory.
*/
protected void bindAdapterFactory(final ServiceReference reference) {
boolean create = true;
if (context == null) {
synchronized ( this.boundAdapterFactories ) {
if (context == null) {
boundAdapterFactories.add(reference);
create = false;
}
}
}
if ( create ) {
registerAdapterFactory(context, reference);
}
}
/**
* Unbind a adapter factory.
*/
protected void unbindAdapterFactory(final ServiceReference reference) {
unregisterAdapterFactory(reference);
}
// ---------- unit testing stuff only --------------------------------------
/**
* Returns the active adapter factories of this manager.
* <p>
* <strong><em>THIS METHOD IS FOR UNIT TESTING ONLY. IT MAY BE REMOVED OR
* MODIFIED WITHOUT NOTICE.</em></strong>
*/
Map<String, AdapterFactoryDescriptorMap> getFactories() {
return descriptors;
}
/**
* Returns the current adapter factory cache.
* <p>
* <strong><em>THIS METHOD IS FOR UNIT TESTING ONLY. IT MAY BE REMOVED OR
* MODIFIED WITHOUT NOTICE.</em></strong>
*/
Map<String, Map<String, List<AdapterFactoryDescriptor>>> getFactoryCache() {
return factoryCache;
}
/**
* Unregisters the {@link AdapterFactory} referred to by the service
* <code>reference</code> from the registry.
*/
private void registerAdapterFactory(final ComponentContext context,
final ServiceReference reference) {
final String[] adaptables = PropertiesUtil.toStringArray(reference.getProperty(ADAPTABLE_CLASSES));
final String[] adapters = PropertiesUtil.toStringArray(reference.getProperty(ADAPTER_CLASSES));
if (adaptables == null || adaptables.length == 0 || adapters == null
|| adapters.length == 0) {
return;
}
for (String clazz : adaptables) {
if (!checkPackage(packageAdmin, clazz)) {
log.warn("Adaptable class {} in factory service {} is not in an exported package.", clazz, reference.getProperty(Constants.SERVICE_ID));
}
}
for (String clazz : adapters) {
if (!checkPackage(packageAdmin, clazz)) {
log.warn("Adapter class {} in factory service {} is not in an exported package.", clazz, reference.getProperty(Constants.SERVICE_ID));
}
}
final AdapterFactoryDescriptor factoryDesc = new AdapterFactoryDescriptor(context,
reference, adapters);
for (final String adaptable : adaptables) {
AdapterFactoryDescriptorMap adfMap = null;
synchronized ( this.descriptors ) {
adfMap = descriptors.get(adaptable);
if (adfMap == null) {
adfMap = new AdapterFactoryDescriptorMap();
descriptors.put(adaptable, adfMap);
}
}
synchronized ( adfMap ) {
adfMap.put(reference, factoryDesc);
}
}
// clear the factory cache to force rebuild on next access
this.factoryCache.clear();
// send event
final EventAdmin localEA = this.eventAdmin;
if ( localEA != null ) {
final Dictionary<String, Object> props = new Hashtable<String, Object>();
props.put(SlingConstants.PROPERTY_ADAPTABLE_CLASSES, adaptables);
props.put(SlingConstants.PROPERTY_ADAPTER_CLASSES, adapters);
localEA.postEvent(new Event(SlingConstants.TOPIC_ADAPTER_FACTORY_ADDED,
props));
}
}
/**
* Check that the package containing the class is exported or is a java.*
* class.
*
* @param packageAdmin the PackageAdmin service
* @param clazz the class name
* @return true if the package is exported
*/
static boolean checkPackage(PackageAdmin packageAdmin, String clazz) {
String packageName = clazz.substring(0, clazz.lastIndexOf('.'));
if (packageName.startsWith("java.")) {
return true;
}
return packageAdmin.getExportedPackage(packageName) != null;
}
/**
* Unregisters the {@link AdapterFactory} referred to by the service
* <code>reference</code> from the registry.
*/
private void unregisterAdapterFactory(final ServiceReference reference) {
synchronized ( this.boundAdapterFactories ) {
boundAdapterFactories.remove(reference);
}
final String[] adaptables = PropertiesUtil.toStringArray(reference.getProperty(ADAPTABLE_CLASSES));
final String[] adapters = PropertiesUtil.toStringArray(reference.getProperty(ADAPTER_CLASSES));
if (adaptables == null || adaptables.length == 0 || adapters == null
|| adapters.length == 0) {
return;
}
boolean factoriesModified = false;
AdapterFactoryDescriptorMap adfMap = null;
for (final String adaptable : adaptables) {
synchronized ( this.descriptors ) {
adfMap = this.descriptors.get(adaptable);
}
if (adfMap != null) {
synchronized ( adfMap ) {
factoriesModified |= (adfMap.remove(reference) != null);
}
}
}
// only remove cache if some adapter factories have actually been
// removed
if (factoriesModified) {
this.factoryCache.clear();
}
// send event
final EventAdmin localEA = this.eventAdmin;
if ( localEA != null ) {
final Dictionary<String, Object> props = new Hashtable<String, Object>();
props.put(SlingConstants.PROPERTY_ADAPTABLE_CLASSES, adaptables);
props.put(SlingConstants.PROPERTY_ADAPTER_CLASSES, adapters);
localEA.postEvent(new Event(SlingConstants.TOPIC_ADAPTER_FACTORY_REMOVED,
props));
}
}
/**
* Returns the map of adapter factories index by adapter (target) class name
* for the given adaptable <code>clazz</code>. If no adapter exists for
* the <code>clazz</code> and empty map is returned.
*
* @param clazz The adaptable <code>Class</code> for which to return the
* adapter factory map by target class name.
* @return The map of adapter factories by target class name. The map may be
* empty if there is no adapter factory for the adaptable
* <code>clazz</code>.
*/
private Map<String, List<AdapterFactoryDescriptor>> getAdapterFactories(final Class<?> clazz) {
final String className = clazz.getName();
Map<String, List<AdapterFactoryDescriptor>> entry = this.factoryCache.get(className);
if (entry == null) {
// create entry
entry = createAdapterFactoryMap(clazz);
this.factoryCache.put(className, entry);
}
return entry;
}
/**
* Creates a new target adapter factory map for the given <code>clazz</code>.
* First all factories defined to support the adaptable class by
* registration are taken. Next all factories for the implemented interfaces
* and finally all base class factories are copied.
*
* @param clazz The adaptable <code>Class</code> for which to build the
* adapter factory map by target class name.
* @return The map of adapter factories by target class name. The map may be
* empty if there is no adapter factory for the adaptable
* <code>clazz</code>.
*/
private Map<String, List<AdapterFactoryDescriptor>> createAdapterFactoryMap(final Class<?> clazz) {
final Map<String, List<AdapterFactoryDescriptor>> afm = new HashMap<String, List<AdapterFactoryDescriptor>>();
// AdapterFactories for this class
AdapterFactoryDescriptorMap afdMap = null;
synchronized ( this.descriptors ) {
afdMap = this.descriptors.get(clazz.getName());
}
if (afdMap != null) {
final List<AdapterFactoryDescriptor> afdSet;
synchronized ( afdMap ) {
afdSet = new ArrayList<AdapterFactoryDescriptor>(afdMap.values());
}
for (final AdapterFactoryDescriptor afd : afdSet) {
final String[] adapters = afd.getAdapters();
for (final String adapter : adapters) {
// to handle service ranking, we add to the end of the list or create a new list
List<AdapterFactoryDescriptor> factoryDescriptors = afm.get(adapter);
if (factoryDescriptors == null) {
factoryDescriptors = new ArrayList<AdapterFactoryDescriptor>();
afm.put(adapter, factoryDescriptors);
}
factoryDescriptors.add(afd);
}
}
}
// AdapterFactories for the interfaces
final Class<?>[] interfaces = clazz.getInterfaces();
for (final Class<?> iFace : interfaces) {
copyAdapterFactories(afm, iFace);
}
// AdapterFactories for the super class
final Class<?> superClazz = clazz.getSuperclass();
if (superClazz != null) {
copyAdapterFactories(afm, superClazz);
}
return afm;
}
/**
* Copies all adapter factories for the given <code>clazz</code> from the
* <code>cache</code> to the <code>dest</code> map except for those
* factories whose target class already exists in the <code>dest</code>
* map.
*
* @param dest The map of target class name to adapter factory into which
* additional factories are copied. Existing factories are not
* replaced.
* @param clazz The adaptable class whose adapter factories are considered
* for adding into <code>dest</code>.
*/
private void copyAdapterFactories(final Map<String, List<AdapterFactoryDescriptor>> dest,
final Class<?> clazz) {
// get the adapter factories for the adaptable clazz
final Map<String, List<AdapterFactoryDescriptor>> scMap = getAdapterFactories(clazz);
// for each target class copy the entry to dest and put it in the list or create the list
for (Map.Entry<String, List<AdapterFactoryDescriptor>> entry : scMap.entrySet()) {
List<AdapterFactoryDescriptor> factoryDescriptors = dest.get(entry.getKey());
if (factoryDescriptors == null) {
factoryDescriptors = new ArrayList<AdapterFactoryDescriptor>();
dest.put(entry.getKey(), factoryDescriptors);
}
for (AdapterFactoryDescriptor descriptor : entry.getValue()) {
factoryDescriptors.add(descriptor);
}
}
}
}