connectorfactory.java

这是一个以JAVA编写的程序,本人还没有试过,是一个简单的温度控制系统

package net.sf.dz.daemon.tcp.client;

import java.net.InetAddress;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.TreeMap;
import java.util.TreeSet;

import org.freehold.jukebox.logger.LogAware;
import org.freehold.jukebox.logger.LogChannel;
import org.freehold.jukebox.logger.Logger;

import net.sf.dz.pnp.MulticastClient;
import net.sf.dz.pnp.MulticastEvent;
import net.sf.dz.pnp.MulticastEventListener;

/**
 * TCP connector factory.
 *
 * <p>
 *
 * This object listens to the broadcast announcements and allows its clients
 * to automatically instantiate TCP connectors connected to the services
 * they are interested in.
 *
 * <p>
 *
 * In other words, this object is a Plug-and-Play facilitator on the client
 * side.
 *
 * @author Copyright &copy; <a href="mailto:[e-mail]">Vadim Tkachenko</a> 2001-2004
 * @version $Id: ConnectorFactory.java,v 1.2 2004/06/28 20:35:47 vtt Exp $
 */
public class ConnectorFactory extends LogAware implements MulticastEventListener {

    public static final LogChannel CH_CF = new LogChannel("ConnectorFactory");

    /**
     * Set of multicast clients that feed us with data.
     */
    private Set multicastClientSet = new HashSet();
    
    /**
     * Map of data sources we have.
     *
     * <p>
     *
     * The key is the service signature, the value is a map where the key is
     * the source address and the value is the service handler.
     */
    private Map spMap = new TreeMap();
    
    public ConnectorFactory(Logger l) {
    
        setLogger(l);
    
        // VT: FIXME: This class should be made configurable and provide
        // different service providers
        
        ServiceProvider sp = new ServiceProvider();
        
        sp.setLogger(getLogger());
        
        spMap.put("DZ DAC Sensors", sp);
        spMap.put("DZ DAC Switches", sp);
    }
    
    /**
     * Add a multicast client to retrieve capabilities from.
     *
     * It is a responsibility of the caller to ensure that the multicast
     * client is up and running.
     *
     * @param client Multicast client preconfigured to recive a certain kind
     * of announce.
     */
    public synchronized void addMulticastClient(MulticastClient client) {
    
        // VT: FIXME: Isn't this kind of redundant?
    
        multicastClientSet.add(client);
        
        client.addListener(this);
        
        complain(LOG_INFO, CH_CF, "Multicast client added: " + client);
    }
    
    /**
     * Start listening to events generated by a (service signature, device
     * address) pair.
     *
     * @param listener An entity that wishes to listen to events generated
     * by a given (service signature, device address) pair.
     * 
     * @param serviceSignature Service signature. Currently supported are
     * "DZ DAC Sensors", "DZ DAC Switches", "DZ Core".
     *
     * @param deviceAddress A service-specific address of a device at the
     * server side access to which is required by the caller.
     *
     * @return An instance of a device connector corresponding with the
     * required device. This instance is to be considered reliable - it will
     * handle transient connection loss or network configuration changes in
     * a graceful manner.
     */
    public synchronized DeviceConnector getConnector(String serviceSignature, String deviceAddress) {
    
        complain(LOG_DEBUG, CH_CF, "Requested " + serviceSignature + "[" + deviceAddress + "]");
        
        return getServiceProvider(serviceSignature).getConnector(deviceAddress);
    }
    
    /**
     * Get a service provider for a service.
     *
     * @param serviceSignature A service signature to get the provider for.
     *
     * @return A service provider. <strong>Important:</strong> we can't
     * return null here, so if there is no known service provider, a
     * transparent dummy one should be returned instead.
     */
    private ServiceProvider getServiceProvider(String serviceSignature) {
    
        ServiceProvider sp = (ServiceProvider)spMap.get(serviceSignature);
        
        if ( sp == null ) {
        
            // VT: FIXME: Actually, have to create one
        
            throw new IllegalStateException("Don't have a service provider for '" + serviceSignature + "'");
        }
        
        return sp;
    }
    
    /**
     * Handle a multicast event received by PnP subsystem.
     */
    public void multicastEventReceived(MulticastClient source, MulticastEvent e) {
    
        //complain(LOG_DEBUG, CH_CF, e.getServiceSignature() + " at " + e.getSourceAddress() + " said: " + e.getMessage());
        
        getServiceProvider(e.getServiceSignature()).multicastEventReceived(e);
    }
    
    protected class DataSourceEvent extends MulticastEvent {
    
        private final Set addressSet = new TreeSet();
    
        public DataSourceEvent(MulticastEvent source) {
        
            super(source);
            
            for ( StringTokenizer st = new StringTokenizer(getMessage(), " "); st.hasMoreTokens(); ) {
            
                addressSet.add(st.nextToken());
            }
        }
        
        public Set getAddressSet() {
        
            return addressSet;
        }
    }
}