/*******************************************************************************
* Copyright (c) 2008 Cambridge Semantics Incorporated.
* 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
*
* File: $Source$
* Created by: Matthew Roy ( <a href="mailto:mroy@cambridgesemantics.com">mroy@cambridgesemantics.com </a>)
* Created on: Jun 10, 2008
* Revision: $Id$
*
* Contributors:
* Cambridge Semantics Incorporated - initial API and implementation
*******************************************************************************/
package org.openanzo.datasource;
import org.osgi.framework.BundleContext;
import org.osgi.framework.InvalidSyntaxException;
import org.osgi.framework.ServiceReference;
import org.osgi.util.tracker.ServiceTracker;
/**
* @author Matthew Roy ( <a href="mailto:mroy@cambridgesemantics.com">mroy@cambridgesemantics.com</a>)
*
*/
public class PrimaryDatasourceTracker extends ServiceTracker {
private final IDatasourceRegistrationListener listener;
IDatasource primaryDatasource = null;
/**
*
* @param context
* @param listener
* @throws InvalidSyntaxException
*/
public PrimaryDatasourceTracker(BundleContext context, IDatasourceRegistrationListener listener) throws InvalidSyntaxException {
super(context, context.createFilter("(&(objectClass=" + IDatasource.class.getName() + ")(isPrimary=true))"), null);
this.listener = listener;
}
@Override
public Object addingService(ServiceReference reference) {
IDatasource datasource = (IDatasource) context.getService(reference);
if (primaryDatasource == null || !primaryDatasource.equals(datasource)) {
listener.registerDatasource(datasource);
this.primaryDatasource = datasource;
}
return datasource;
}
@Override
public void removedService(ServiceReference reference, Object serviceObject) {
IDatasource datasource = (IDatasource) serviceObject;
if (primaryDatasource != null && primaryDatasource.equals(datasource)) {
listener.unregisterDatasource(datasource);
context.ungetService(reference);
}
}
}