doc/tutorials/EclipseCON 2009/org.eclipse.ecf.tutorial.osgi.services.discovery/src/org/eclipse/ecf/internal/osgi/services/discovery/Activator.java

/*******************************************************************************
 * Copyright (c) 2009 EclipseSource and others. All rights reserved. This
 * program and the accompanying materials are made available under the terms of
 * the Eclipse Public License v1.0 which accompanies this distribution, and is
 * available at http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   EclipseSource - initial API and implementation
 ******************************************************************************/
package org.eclipse.ecf.internal.osgi.services.discovery;

import org.eclipse.ecf.tutorial.osgi.services.discovery.ServicePublicationHandler;

import org.eclipse.core.runtime.Status;
import org.eclipse.ecf.core.util.Trace;

import java.util.Dictionary;
import java.util.Hashtable;
import org.eclipse.core.runtime.IStatus;
import org.eclipse.ecf.core.util.LogHelper;
import org.eclipse.ecf.core.util.SystemLogService;
import org.eclipse.ecf.discovery.IDiscoveryAdvertiser;
import org.eclipse.ecf.discovery.IDiscoveryLocator;
import org.osgi.framework.*;
import org.osgi.service.discovery.*;
import org.osgi.service.log.LogService;
import org.osgi.util.tracker.ServiceTracker;

public class Activator implements BundleActivator {

	public static final String PLUGIN_ID = "org.eclipse.ecf.tutorial.osgi.services.discovery"; //$NON-NLS-1$

	private static final long DISCOVERY_TIMEOUT = 5000;

	private ServiceTracker servicePublicationTracker;
	private ServiceTracker locatorTracker;
	private ServiceTracker advertiserTracker;
	private ServiceTracker discoveredServiceTrackerTracker;

	private ServiceTracker logServiceTracker = null;
	private LogService logService = null;

	private BundleContext context;
	private static Activator plugin;
	private ServicePublicationHandler servicePublicationHandler;

	public static final Activator getDefault() {
		return plugin;
	}

	/* (non-Javadoc)
	 * @see org.osgi.framework.BundleActivator#start(org.osgi.framework.BundleContext)
	 */
	public void start(BundleContext ctxt) throws Exception {
		plugin = this;
		this.context = ctxt;
		servicePublicationHandler = new ServicePublicationHandler();

		servicePublicationTracker = new ServiceTracker(context,
				ServicePublication.class.getName(), servicePublicationHandler);
		servicePublicationTracker.open();

		// register the discovery service which is provided by SPH
		Dictionary props = new Hashtable();
		props.put(Discovery.PROP_KEY_VENDOR_NAME, "Eclipse.org");
		props.put(Discovery.PROP_KEY_PRODUCT_NAME, "ECF Discovery");
		props.put(Discovery.PROP_KEY_PRODUCT_VERSION, "1.0.0");
		props.put(Discovery.PROP_KEY_SUPPORTED_PROTOCOLS, "SLP|mDNS|DNS-SRV");
		ctxt.registerService(Discovery.class.getName(),
				servicePublicationHandler, props);
	}

	protected LogService getLogService() {
		if (logServiceTracker == null) {
			logServiceTracker = new ServiceTracker(this.context,
					LogService.class.getName(), null);
			logServiceTracker.open();
		}
		logService = (LogService) logServiceTracker.getService();
		if (logService == null)
			logService = new SystemLogService(PLUGIN_ID);
		return logService;
	}

	public void log(IStatus status) {
		if (logService == null)
			logService = getLogService();
		if (logService != null)
			logService.log(null, LogHelper.getLogCode(status), LogHelper
					.getLogMessage(status), status.getException());
	}

	public void log(ServiceReference sr, IStatus status) {
		log(sr, LogHelper.getLogCode(status), LogHelper.getLogMessage(status),
				status.getException());
	}

	public void log(ServiceReference sr, int level, String message, Throwable t) {
		if (logService == null)
			logService = getLogService();
		if (logService != null)
			logService.log(sr, level, message, t);
	}

	public BundleContext getContext() {
		return context;
	}

	public ServicePublicationHandler getServicePublicationHandler() {
		return servicePublicationHandler;
	}

	public IDiscoveryLocator getLocator() {
		if (locatorTracker == null) {
			locatorTracker = new ServiceTracker(this.context,
					IDiscoveryLocator.class.getName(), null);
			locatorTracker.open();
		}
		try {
			return (IDiscoveryLocator) locatorTracker
					.waitForService(DISCOVERY_TIMEOUT);
		} catch (InterruptedException e) {
			log("getLocator", "Cannot get IDiscoveryAdvertiser", e); //$NON-NLS-1$
		}
		return null;
	}

	public IDiscoveryAdvertiser getAdvertiser() {
		if (advertiserTracker == null) {
			advertiserTracker = new ServiceTracker(this.context,
					IDiscoveryAdvertiser.class.getName(), null);
			advertiserTracker.open();
		}
		try {
			return (IDiscoveryAdvertiser) advertiserTracker
					.waitForService(DISCOVERY_TIMEOUT);
		} catch (InterruptedException e) {
			log("getAdvertiser", "Cannot get IDiscoveryAdvertiser", e); //$NON-NLS-1$
		}
		return null;
	}

	public ServiceReference[] getDiscoveredServiceTrackerReferences() {
		if (discoveredServiceTrackerTracker == null) {
			discoveredServiceTrackerTracker = new ServiceTracker(this.context,
					DiscoveredServiceTracker.class.getName(), null);
			discoveredServiceTrackerTracker.open();
		}
		return discoveredServiceTrackerTracker.getServiceReferences();
	}

	/* (non-Javadoc)
	 * @see org.osgi.framework.BundleActivator#stop(org.osgi.framework.BundleContext)
	 */
	public void stop(BundleContext context) throws Exception {
		if (discoveredServiceTrackerTracker != null) {
			discoveredServiceTrackerTracker.close();
			discoveredServiceTrackerTracker = null;
		}
		if (locatorTracker != null) {
			locatorTracker.close();
			locatorTracker = null;
		}
		if (advertiserTracker != null) {
			advertiserTracker.close();
			advertiserTracker = null;
		}
		if (servicePublicationTracker != null) {
			servicePublicationTracker.close();
			servicePublicationTracker = null;
		}
		if (servicePublicationHandler != null) {
			servicePublicationHandler.dispose();
			servicePublicationHandler = null;
		}
		if (logServiceTracker != null) {
			logServiceTracker.close();
			logServiceTracker = null;
			logService = null;
		}
		this.context = null;
		plugin = null;
	}

	public void log(String method, String message, Throwable t) {
		IStatus status = new Status(IStatus.ERROR, Activator.PLUGIN_ID, IStatus.ERROR, method + ":" + message, t); //$NON-NLS-1$
		log(status);
		Trace.catching(Activator.PLUGIN_ID, DebugOptions.EXCEPTIONS_CATCHING, this.getClass(),
				method + ":" + message, t); //$NON-NLS-1$
	}
}