Mercurial > hg > release > thermostat-1.0
view common/core/src/main/java/com/redhat/thermostat/common/MultipleServiceTracker.java @ 1412:a0592d702416
Update copyright year in release branch.
reviewed-by: neugens
review-thread: http://icedtea.classpath.org/pipermail/thermostat/2014-June/009965.html
PR1821
author | Jon VanAlten <jon.vanalten@redhat.com> |
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date | Tue, 03 Jun 2014 11:55:56 -0600 |
parents | ccac9bcabaa0 |
children |
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/* * Copyright 2012-2014 Red Hat, Inc. * * This file is part of Thermostat. * * Thermostat is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published * by the Free Software Foundation; either version 2, or (at your * option) any later version. * * Thermostat is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with Thermostat; see the file COPYING. If not see * <http://www.gnu.org/licenses/>. * * Linking this code with other modules is making a combined work * based on this code. Thus, the terms and conditions of the GNU * General Public License cover the whole combination. * * As a special exception, the copyright holders of this code give * you permission to link this code with independent modules to * produce an executable, regardless of the license terms of these * independent modules, and to copy and distribute the resulting * executable under terms of your choice, provided that you also * meet, for each linked independent module, the terms and conditions * of the license of that module. An independent module is a module * which is not derived from or based on this code. If you modify * this code, you may extend this exception to your version of the * library, but you are not obligated to do so. If you do not wish * to do so, delete this exception statement from your version. */ package com.redhat.thermostat.common; import java.util.ArrayList; import java.util.Collection; import java.util.HashMap; import java.util.Map; import java.util.Map.Entry; import java.util.Objects; import org.osgi.framework.BundleContext; import org.osgi.framework.ServiceReference; import org.osgi.util.tracker.ServiceTracker; import org.osgi.util.tracker.ServiceTrackerCustomizer; /** * A {@link ServiceTracker} for multiple services. This class is intended to be * used within BundleActivator implementations that require some action be taken * only after certain services have appeared. */ public class MultipleServiceTracker { public interface Action { public void dependenciesAvailable(Map<String, Object> services); public void dependenciesUnavailable(); } class InternalServiceTrackerCustomizer implements ServiceTrackerCustomizer { @Override public Object addingService(ServiceReference reference) { Object service = context.getService(reference); services.put(getServiceClassName(reference), context.getService(reference)); if (allServicesReady()) { action.dependenciesAvailable(services); } return service; } @Override public void modifiedService(ServiceReference reference, Object service) { // We don't actually need to do anything here. } @Override public void removedService(ServiceReference reference, Object service) { if (servicesWillBecomeNotReady(getServiceClassName(reference))) { action.dependenciesUnavailable(); } services.put(getServiceClassName(reference), null); context.ungetService(reference); } private String getServiceClassName(ServiceReference reference) { return ((String[]) reference.getProperty(org.osgi.framework.Constants.OBJECTCLASS))[0]; } } private Map<String, Object> services; private Collection<ServiceTracker> trackers; private Action action; private BundleContext context; public MultipleServiceTracker(BundleContext context, Class<?>[] classes, Action action) { Objects.requireNonNull(context); Objects.requireNonNull(classes); Objects.requireNonNull(action); this.context = context; services = new HashMap<>(); trackers = new ArrayList<>(); for (Class<?> clazz: classes) { InternalServiceTrackerCustomizer tc = new InternalServiceTrackerCustomizer(); ServiceTracker tracker = new ServiceTracker(context, clazz.getName(), tc); trackers.add(tracker); services.put(clazz.getName(), null); } this.action = action; } public void open() { for (ServiceTracker tracker : trackers) { tracker.open(); } } public void close() { for (ServiceTracker tracker: trackers) { tracker.close(); } } private boolean allServicesReady() { for (Entry<String, Object> entry: services.entrySet()) { if (entry.getValue() == null) { return false; } } return true; } private boolean servicesWillBecomeNotReady(String serviceName) { return (allServicesReady() && services.containsKey(serviceName)); } }