activator.java

java在网页中操作摄像头的源码,质量清晰,可进行语音

/*
 *  WebCam Producer
 *
 * Copyright (C) 2004  Didier Donsez
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 *
 * Contact: Didier Donsez ([e-mail])
 * Contributor(s):
 *
**/
package fr.imag.adele.bundle.webcamproducer.impl;

import java.io.InputStream;
import java.util.Dictionary;
import java.util.Enumeration;
import java.util.Hashtable;

import jmfdemo.FrameGrabber;
import jmfdemo.FrameGrabberException;

import org.osgi.framework.BundleActivator;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleException;
import org.osgi.framework.ServiceRegistration;
import org.osgi.service.wireadmin.Producer;

import fr.imag.adele.bundle.webcamproducer.ImageGrabber;

/**
 * This activator read configuration properties from a file
 * and initialize a Producer service with these properties
 * and register it
 *
 * @version 	1.0 22/02/2004 
 * @author 	Didier Donsez ([e-mail])
 */

public class Activator implements BundleActivator {

	protected BundleContext context = null;
	private FrameGrabber frameGrabber;
	private ServiceRegistration prodServReg;
	private ServiceRegistration imggrabServReg;


	/**
	 * Called upon starting of the bundle.
	 *
	 * @param   context  The bundle context passed by the framework
	 * @exception   Exception
	 */
	public void start(BundleContext context) throws BundleException {
		this.context = context;

		// Load properties from configLocation file
		// and init the frame grabber
		try {
			InputStream is=config(context);
			if(is!=null) {
			      frameGrabber = new FrameGrabber(is);      
		      } else {
			      frameGrabber = new FrameGrabber();      
		      }
		      frameGrabber.start();
		} catch (FrameGrabberException fge) {
			fge.printStackTrace();
			throw new BundleException("Error creating frame grabber", fge);
		}
		
		Dictionary p;

		// instanciate the service implementation
		Producer prod=new ImageProducer(context,frameGrabber);
		// registered the ProducerService		
		p=new Hashtable();
		p.put( org.osgi.service.wireadmin.WireConstants.WIREADMIN_PRODUCER_FLAVORS,
			new Class[] { java.awt.Image.class });
		p.put( org.osgi.framework.Constants.SERVICE_PID,
			"fr.imag.adele.osgi.util.webcam");
		p.put( org.osgi.framework.Constants.SERVICE_DESCRIPTION,
			"grabs a java.awt.Image from a WebCam");
		prodServReg = context.registerService(
			Producer.class.getName(),
			prod,
			p);
			
		// instanciate the service implementation
		ImageGrabber imageGrabber=new ImageGrabberImpl(context,frameGrabber);
		// registered the ProducerService		
		p=new Hashtable();
		p.put( org.osgi.framework.Constants.SERVICE_DESCRIPTION,
			"grabs a java.awt.Image from a WebCam");
		imggrabServReg = context.registerService(
			ImageGrabber.class.getName(),
			imageGrabber,
			p
			);
	}
	
	public void stop(BundleContext context) throws BundleException {
		frameGrabber.end();
	}
	
	// configuration section
	
	protected static final String CONFIGFILE = "/config.properties";

	protected InputStream config(BundleContext context) throws BundleException {
		// Get the Config-Location value from the manifest

		String configLocation = null;
		Dictionary dict = context.getBundle().getHeaders();
		Enumeration enum1 = dict.keys();
		while (enum1.hasMoreElements()) {
			Object nextKey = enum1.nextElement();
			Object nextElem = dict.get(nextKey);
			if (nextKey.equals("Config-Location")) {
				configLocation = nextElem.toString();
				break;
			}
		}
		if (configLocation == null) {
			configLocation = CONFIGFILE;
		}

		return  getClass().getResourceAsStream(configLocation);
	}
}