| /* |
| * 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.installer.provider.file.impl; |
| |
| import java.util.Dictionary; |
| import java.util.Hashtable; |
| import java.util.List; |
| |
| import org.apache.sling.installer.api.OsgiInstaller; |
| import org.apache.sling.installer.api.UpdateHandler; |
| import org.apache.sling.settings.SlingSettingsService; |
| 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>ServicesListener</code> listens for the required services |
| * and starts/stops the scanners based on the availability of the |
| * services. |
| */ |
| public class ServicesListener { |
| |
| /** The logger. */ |
| private final Logger logger = LoggerFactory.getLogger(this.getClass()); |
| |
| /** The name of the installer service. */ |
| private static final String INSTALLER_SERVICE_NAME = OsgiInstaller.class.getName(); |
| |
| /** The name of the settings service. */ |
| private static final String SETTINGS_SERVICE_NAME = SlingSettingsService.class.getName(); |
| |
| /** The bundle context. */ |
| private final BundleContext bundleContext; |
| |
| /** The listener for the installer. */ |
| private final Listener installerListener; |
| |
| /** The listener for the settings service. */ |
| private final Listener settingsListener; |
| |
| /** The file installer. */ |
| private final FileInstaller installer; |
| |
| /** Service registration. */ |
| private ServiceRegistration registration; |
| |
| private boolean running = false; |
| |
| public ServicesListener(final BundleContext bundleContext, |
| final List<ScanConfiguration> configs) { |
| this.bundleContext = bundleContext; |
| boolean writeBack = true; |
| final Object writeBackObj = Activator.getProp(this.bundleContext, Activator.KEY_WRITEBACK); |
| if ( writeBackObj != null && "false".equalsIgnoreCase(writeBackObj.toString())) { |
| writeBack = false; |
| } |
| this.installer = new FileInstaller(configs, writeBack); |
| this.installerListener = new Listener(INSTALLER_SERVICE_NAME); |
| this.settingsListener = new Listener(SETTINGS_SERVICE_NAME); |
| this.installerListener.start(); |
| this.settingsListener.start(); |
| } |
| |
| public synchronized void notifyChange() { |
| final boolean shouldRun = this.installer.hasConfigurations(); |
| if ( (shouldRun && !running) || (!shouldRun && running) ) { |
| final OsgiInstaller installer = (OsgiInstaller)this.installerListener.getService(); |
| final SlingSettingsService settings = (SlingSettingsService)this.settingsListener.getService(); |
| if ( installer != null && settings != null && !running ) { |
| logger.debug("Starting scanner"); |
| this.startScanner(installer, settings); |
| } else if ( running && (installer == null || settings == null) ) { |
| logger.debug("Stopping scanner"); |
| this.stopScanner(); |
| } |
| } |
| } |
| |
| /** |
| * Deactivate this listener. |
| */ |
| public void deactivate() { |
| this.installerListener.deactivate(); |
| this.stopScanner(); |
| } |
| |
| /** Vendor of all registered services. */ |
| public static final String VENDOR = "The Apache Software Foundation"; |
| |
| private void startScanner(final OsgiInstaller installer, final SlingSettingsService settings) { |
| if ( !running ) { |
| this.installer.start(installer, settings); |
| final Dictionary<String, Object> props = new Hashtable<String, Object>(); |
| props.put(Constants.SERVICE_DESCRIPTION, "Apache Sling File Installer Controller Service"); |
| props.put(Constants.SERVICE_VENDOR, VENDOR); |
| props.put(UpdateHandler.PROPERTY_SCHEMES, this.installer.getSchemes()); |
| |
| this.registration = this.bundleContext.registerService(UpdateHandler.class.getName(), |
| this.installer, props); |
| running = true; |
| } |
| } |
| |
| private void stopScanner() { |
| if ( running ) { |
| if ( this.registration != null ) { |
| this.registration.unregister(); |
| this.registration = null; |
| } |
| this.installer.stop(); |
| running = false; |
| } |
| } |
| |
| protected final class Listener implements ServiceListener { |
| |
| private final String serviceName; |
| |
| private ServiceReference reference; |
| private Object service; |
| |
| public Listener(final String serviceName) { |
| this.serviceName = serviceName; |
| } |
| |
| public void start() { |
| this.retainService(); |
| try { |
| bundleContext.addServiceListener(this, "(" |
| + Constants.OBJECTCLASS + "=" + serviceName + ")"); |
| } catch (final InvalidSyntaxException ise) { |
| // this should really never happen |
| throw new RuntimeException("Unexpected exception occured.", ise); |
| } |
| } |
| |
| public void deactivate() { |
| bundleContext.removeServiceListener(this); |
| } |
| |
| public synchronized Object getService() { |
| return this.service; |
| } |
| 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(); |
| } |
| } |
| } |
| } |
| |
| 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.service == null ) { |
| this.retainService(); |
| } else if ( event.getType() == ServiceEvent.UNREGISTERING && this.service != null ) { |
| this.releaseService(); |
| } |
| } |
| } |
| } |