/*
* 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.servlets.post.impl;
import java.util.Dictionary;
import java.util.Hashtable;
import java.util.IdentityHashMap;
import java.util.Map;
import org.apache.felix.scr.annotations.Activate;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Deactivate;
import org.apache.sling.api.SlingHttpServletRequest;
import org.apache.sling.api.servlets.HtmlResponse;
import org.apache.sling.servlets.post.PostOperation;
import org.apache.sling.servlets.post.PostResponse;
import org.apache.sling.servlets.post.SlingPostOperation;
import org.apache.sling.servlets.post.SlingPostProcessor;
import org.apache.sling.servlets.post.impl.helper.HtmlResponseProxy;
import org.osgi.framework.BundleContext;
import org.osgi.framework.Constants;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.ServiceEvent;
import org.osgi.framework.ServiceListener;
import org.osgi.framework.ServiceReference;
import org.osgi.framework.ServiceRegistration;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* The <code>PostOperationProxyProvider</code> listens for legacy
* {@link SlingPostOperation} services being registered and wraps them with a
* proxy for the new {@link PostOperation} API and registers the procies.
*/
@Component(specVersion = "1.1", metatype = false)
public class PostOperationProxyProvider implements ServiceListener {
private final Logger log = LoggerFactory.getLogger(getClass());
/**
* The service listener filter to listen for SlingPostOperation services
*/
private static final String REFERENCE_FILTER = "(" + Constants.OBJECTCLASS
+ "=" + SlingPostOperation.SERVICE_NAME + ")";
// maps references to the SlingPostOperation services to the registrations
// of the PostOperation proxies for unregistration purposes
private final Map<ServiceReference, ServiceRegistration> proxies = new IdentityHashMap<ServiceReference, ServiceRegistration>();
// The DS component context to access the services to proxy
private BundleContext bundleContext;
// DS activation/deactivation
/**
* Activates the proxy provider component:
* <ol>
* <li>Keep BundleContext reference</li>
* <li>Start listening for SlingPostOperation services</li>
* <li>Register proxies for all existing SlingPostOperation services</li>
* </ol>
*/
@SuppressWarnings("unused")
@Activate
private void activate(final BundleContext bundleContext) {
this.bundleContext = bundleContext;
try {
bundleContext.addServiceListener(this, REFERENCE_FILTER);
final ServiceReference[] serviceReferences = bundleContext.getServiceReferences(
SlingPostOperation.SERVICE_NAME, null);
if (serviceReferences != null) {
for (ServiceReference serviceReference : serviceReferences) {
register(serviceReference);
}
}
} catch (InvalidSyntaxException ise) {
// not expected for tested static filter
// TODO:log !!
}
}
/**
* Deactivates the proxy provide component:
* <ol>
* <li>Unregister as a service listener</li>
* <li>Unregister all proxies</li>
* <li>Drop BundleContext reference</li>
* </ol>
*/
@SuppressWarnings("unused")
@Deactivate
private void deactivate() {
this.bundleContext.removeServiceListener(this);
final ServiceReference[] serviceReferences;
synchronized (this.proxies) {
serviceReferences = this.proxies.keySet().toArray(
new ServiceReference[this.proxies.size()]);
}
for (ServiceReference serviceReference : serviceReferences) {
unregister(serviceReference);
}
this.bundleContext = null;
}
// ServiceEvent handling
public void serviceChanged(ServiceEvent event) {
/*
* There is a slight chance for a race condition on deactivation where
* the component may be deactivating and the bundle context reference
* has been removed but the framework is still sending service events.
* In this situation we don't want to handle the event any way and so we
* can safely ignore it
*/
if (this.bundleContext == null) {
return;
}
switch (event.getType()) {
case ServiceEvent.REGISTERED:
register(event.getServiceReference());
break;
case ServiceEvent.MODIFIED:
update(event.getServiceReference());
break;
case ServiceEvent.UNREGISTERING:
unregister(event.getServiceReference());
break;
}
}
/**
* Access SlingPostOperation service and register proxy.
* <p>
* Called by serviceChanged
*/
private void register(final ServiceReference serviceReference) {
final SlingPostOperation service = (SlingPostOperation) this.bundleContext.getService(serviceReference);
final PostOperationProxy proxy = new PostOperationProxy(service);
final BundleContext bundleContext = serviceReference.getBundle().getBundleContext();
final Dictionary<String, Object> props = copyServiceProperties(serviceReference);
final ServiceRegistration reg = bundleContext.registerService(
PostOperation.SERVICE_NAME, proxy, props);
log.debug("Registering {}", proxy);
synchronized (this.proxies) {
this.proxies.put(serviceReference, reg);
}
}
/**
* Update proxy service registration properties
* <p>
* Called by serviceChanged
*/
private void update(final ServiceReference serviceReference) {
final ServiceRegistration proxyRegistration;
synchronized (this.proxies) {
proxyRegistration = this.proxies.get(serviceReference);
}
if (proxyRegistration != null) {
log.debug("Updating {}", proxyRegistration);
proxyRegistration.setProperties(copyServiceProperties(serviceReference));
}
}
/**
* Unregister proxy and unget SlingPostOperation service
* <p>
* Called by serviceChanged
*/
private void unregister(final ServiceReference serviceReference) {
final ServiceRegistration proxyRegistration;
synchronized (this.proxies) {
proxyRegistration = this.proxies.remove(serviceReference);
}
if (proxyRegistration != null) {
log.debug("Unregistering {}", proxyRegistration);
this.bundleContext.ungetService(serviceReference);
proxyRegistration.unregister();
}
}
// Helpers
/**
* Creates a Dictionary for use as the service registration properties of
* the PostOperation proxy.
*/
private Dictionary<String, Object> copyServiceProperties(
final ServiceReference serviceReference) {
final Dictionary<String, Object> props = new Hashtable<String, Object>();
for (String key : serviceReference.getPropertyKeys()) {
props.put(key, serviceReference.getProperty(key));
}
props.put(PostOperation.PROP_OPERATION_NAME,
serviceReference.getProperty(SlingPostOperation.PROP_OPERATION_NAME));
props.put(Constants.SERVICE_DESCRIPTION, "Proxy for "
+ serviceReference);
return props;
}
/**
* The <code>PostOperationProxy</code> is the proxy implementing the
* {@link PostOperation} service interface by calling the
* {@link SlingPostOperation} service.
*/
private class PostOperationProxy implements PostOperation {
private final SlingPostOperation delegatee;
PostOperationProxy(final SlingPostOperation delegatee) {
this.delegatee = delegatee;
}
public String toString() {
return getClass().getSimpleName() + " for " + delegatee.getClass().getName();
}
public void run(SlingHttpServletRequest request, PostResponse response,
SlingPostProcessor[] processors) {
HtmlResponse apiResponse = new HtmlResponseProxy(response);
delegatee.run(request, apiResponse, processors);
}
}
}