http://bugswarm.net/docs/write-a-swarm-enabled-app

gistfile1.java

package earthquake_detector;

import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.util.tracker.ServiceTracker;

import com.buglabs.bug.accelerometer.pub.IAccelerometerSampleProvider;
import com.buglabs.bug.module.gps.pub.IPositionProvider;
import com.buglabs.bug.swarm.connector.pub.ISwarmConnector;
import com.buglabs.application.ServiceTrackerHelper;

/**
 * This is the activator that serves as the application's main() or start.
 * 
 * The OSGi services that are used in this application are defined in the variable 'services', and are 
 * used to construct a ServiceTracker and MannagedRunnable that is created and started inside a thread when/if
 * all the services are available.
 * 
 * @author kgilmer
 *
 */
public class Activator implements BundleActivator {
	public static final String KEY_LATITUDE = "latitude";
	public static final String KEY_LONGITUDE = "longitude";
	public static final String KEY_LOCATION = "location";
	public static final String KEY_ACCELERATION = "acceleration";

	private String services[] = new String[] {
			ISwarmConnector.class.getName(), 
			IAccelerometerSampleProvider.class.getName(),
			IPositionProvider.class.getName()
			};
	private ServiceTracker st; 
	
	public void start(BundleContext context) throws Exception {
		st = ServiceTrackerHelper.openServiceTracker(context, services, new Monitor());
	}

	public void stop(BundleContext context) throws Exception {
		st.close();
	}
}