| /* |
| * 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.launchpad.installer.impl; |
| |
| import java.util.Dictionary; |
| import java.util.Hashtable; |
| |
| import org.apache.sling.installer.api.OsgiInstaller; |
| import org.apache.sling.installer.api.event.InstallationListener; |
| import org.apache.sling.launchpad.api.LaunchpadContentProvider; |
| import org.apache.sling.launchpad.api.StartupHandler; |
| 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; |
| |
| /** |
| * The <code>ServicesListener</code> listens for the required services |
| * and starts the installation support if all services are available. |
| */ |
| public class ServicesListener { |
| |
| /** The bundle context. */ |
| private final BundleContext bundleContext; |
| |
| /** The listener for the installer. */ |
| private final Listener installerListener; |
| |
| /** The listener for the provider. */ |
| private final Listener providerListener; |
| |
| /** The listener for the startup handler. */ |
| private final Listener startupListener; |
| |
| /** The registration of the launchpad listener. */ |
| private ServiceRegistration launchpadListenerReg; |
| |
| /** Boolean marker to not reprocess things. */ |
| private volatile boolean installed = false; |
| |
| private LaunchpadListener launchpadListener; |
| |
| /** |
| * Start listeners |
| */ |
| public ServicesListener(final BundleContext bundleContext) { |
| this.bundleContext = bundleContext; |
| this.installerListener = new Listener(OsgiInstaller.class.getName()); |
| this.providerListener = new Listener(LaunchpadContentProvider.class.getName()); |
| this.startupListener = new Listener(StartupHandler.class.getName()); |
| this.startupListener.start(); |
| this.installerListener.start(); |
| this.providerListener.start(); |
| } |
| |
| /** |
| * Notify of service changes from the listeners. |
| * If all services are available, register listener and pass resources |
| * to the OSGi installer. |
| */ |
| public synchronized void notifyChange() { |
| // check if all services are available |
| final OsgiInstaller installer = (OsgiInstaller)this.installerListener.getService(); |
| final LaunchpadContentProvider lcp = (LaunchpadContentProvider)this.providerListener.getService(); |
| final StartupHandler handler = (StartupHandler)this.startupListener.getService(); |
| |
| if ( installer != null && lcp != null && handler != null ) { |
| if ( !this.installed ) { |
| this.installed = true; |
| this.launchpadListener = new LaunchpadListener(handler); |
| final Dictionary<String, Object> props = new Hashtable<String, Object>(); |
| props.put(Constants.SERVICE_DESCRIPTION, "Apache Sling Launchpad Startup Listener"); |
| props.put(Constants.SERVICE_VENDOR, "The Apache Software Foundation"); |
| this.launchpadListenerReg = this.bundleContext.registerService(InstallationListener.class.getName(), launchpadListener, props); |
| LaunchpadConfigInstaller.install(installer, lcp); |
| } |
| } |
| } |
| |
| /** |
| * Deactivate this listener. |
| */ |
| public void deactivate() { |
| this.installerListener.deactivate(); |
| this.providerListener.deactivate(); |
| this.startupListener.deactivate(); |
| if ( this.launchpadListenerReg != null ) { |
| this.launchpadListener.stop(); |
| this.launchpadListenerReg.unregister(); |
| this.launchpadListenerReg = null; |
| } |
| this.launchpadListener = null; |
| } |
| |
| /** |
| * Helper class listening for service events for a defined service. |
| */ |
| protected final class Listener implements ServiceListener { |
| |
| /** The name of the service. */ |
| private final String serviceName; |
| |
| /** The service reference. */ |
| private volatile ServiceReference reference; |
| |
| /** The service. */ |
| private volatile Object service; |
| |
| /** |
| * Constructor |
| */ |
| public Listener(final String serviceName) { |
| this.serviceName = serviceName; |
| } |
| |
| /** |
| * Start the listener. |
| * First register a service listener and then check for the service. |
| */ |
| public void start() { |
| try { |
| bundleContext.addServiceListener(this, "(" |
| + Constants.OBJECTCLASS + "=" + serviceName + ")"); |
| } catch (final InvalidSyntaxException ise) { |
| // this should really never happen |
| throw new RuntimeException("Unexpected exception occured.", ise); |
| } |
| this.retainService(); |
| } |
| |
| /** |
| * Unregister the listener. |
| */ |
| public void deactivate() { |
| bundleContext.removeServiceListener(this); |
| } |
| |
| /** |
| * Return the service (if available) |
| */ |
| public synchronized Object getService() { |
| return this.service; |
| } |
| |
| /** |
| * Try to get the service and notify the change. |
| */ |
| private synchronized void retainService() { |
| if ( this.reference == null ) { |
| this.reference = bundleContext.getServiceReference(this.serviceName); |
| if ( this.reference != null ) { |
| this.service = bundleContext.getService(this.reference); |
| if ( this.service == null ) { |
| this.reference = null; |
| } else { |
| notifyChange(); |
| } |
| } |
| } |
| } |
| |
| /** |
| * Try to release the service and notify the change. |
| */ |
| private synchronized void releaseService() { |
| if ( this.reference != null ) { |
| this.service = null; |
| bundleContext.ungetService(this.reference); |
| this.reference = null; |
| notifyChange(); |
| } |
| } |
| |
| /** |
| * @see org.osgi.framework.ServiceListener#serviceChanged(org.osgi.framework.ServiceEvent) |
| */ |
| public void serviceChanged(ServiceEvent event) { |
| if (event.getType() == ServiceEvent.REGISTERED) { |
| this.retainService(); |
| } else if ( event.getType() == ServiceEvent.UNREGISTERING ) { |
| this.releaseService(); |
| } |
| } |
| } |
| } |