broadcaster.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;

import java.io.BufferedReader;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.TreeMap;
import java.util.TreeSet;

import org.freehold.jukebox.logger.LogChannel;

import net.sf.dz.daemon.onewire.OneWireServer;
import net.sf.dz.daemon.onewire.DeviceContainer;
import net.sf.dz.daemon.onewire.TemperatureContainer;
import net.sf.dz.daemon.onewire.SwitchContainerListener;
import net.sf.dz.daemon.onewire.TemperatureContainerListener;

/**
 * The TCP broadcaster.
 *
 * Broadcasts the device state change notifications over the TCP connection.
 *
 * @author Copyright &copy; <a href="mailto:[e-mail]">Vadim Tkachenko</a> 2001-2002
 * @version $Id: Broadcaster.java,v 1.10 2004/06/28 20:35:47 vtt Exp $
 */
public class Broadcaster extends Connector implements TemperatureContainerListener {

    public static final LogChannel CH_BC = new LogChannel("TCP/Broadcaster");
    
    /**
     * Set of known temperature sensor addresses.
     */
     private Set deviceSet = new TreeSet();

    /**
     * Mapping from the sensor address to the last known temperature value.
     */
    private Map temperatureCache = new TreeMap();
    
    protected LogChannel getLogChannel() {
    
        return CH_BC;
    }

    protected String getAnnounce() {
    
        StringBuffer sb = new StringBuffer();
        
        sb.append("DZ DAC Sensors").append(super.getAnnounce()).append("/");
        
        synchronized ( deviceSet ) {
        
            for ( Iterator i = deviceSet.iterator(); i.hasNext(); ) {
            
                sb.append(" ").append(i.next().toString());
            }
        }
    
        return sb.toString();
    }

    protected String getServiceSignature() {
    
        return "DZ DAC Sensors";
    }

    protected int getDefaultListenPort() {
    
        return 5000;
    }
    
    protected int getDefaultBroadcastPort() {
    
        return 5001;
    }
    
    protected void shutdown2(Throwable cause) throws Throwable {

    }

    public synchronized void currentTemperatureChanged(String address, double temperature) {
    
        temperatureCache.put(address, new Double(temperature));
    
        for ( Iterator i = iterator(); i.hasNext(); ) {
        
            ConnectionHandler ch = (ConnectionHandler)i.next();
            
            try {
            
                ch.send(address + " " + temperature);
                
            } catch ( IllegalStateException ex ) {
            
                // VT: NOTE: This usually happens when the client has
                // already disconnected and the handler is stopped, but not
                // removed from the list yet.  When time permits, more
                // elegant solution is due.
                
                i.remove();
            }
        }
    }
    
    protected synchronized void broadcastArrival(String address, String type) {
    
        // VT: Type is ignored at this point
    
        for ( Iterator si = serverSet.iterator(); si.hasNext(); ) {
        
            OneWireServer s = (OneWireServer)si.next();
            DeviceContainer dc = s.getDeviceContainer(address);
            
            // The only containers we care about are temperature containers
            
            if ( (dc != null) && (dc instanceof TemperatureContainer) ) {
            
                deviceSet.add(address);
            
                announce(getAnnounce());
                
                for ( Iterator i = iterator(); i.hasNext(); ) {
                
                    ConnectionHandler ch = (ConnectionHandler)i.next();
                    
                    ch.iHave();
                    ch.send("+ " + address);
                }
                
                return;
            }
        }
    }
    
    protected synchronized void broadcastDeparture(String address) {
    
        if ( !deviceSet.contains(address) ) {
        
            // This is not ours
            return;
        }

        deviceSet.remove(address);
        temperatureCache.remove(address);
        
        announce(getAnnounce());
    
        for ( Iterator i = iterator(); i.hasNext(); ) {
        
            ConnectionHandler ch = (ConnectionHandler)i.next();
            
            ch.iHave();
            ch.send("- " + address);
        }
    }

    protected synchronized void broadcastFault(String address, String message) {
    
        for ( Iterator i = iterator(); i.hasNext(); ) {
        
            ConnectionHandler ch = (ConnectionHandler)i.next();
            
            ch.send("E " + address + " " + message);
        }
    }

    protected ConnectionHandler createHandler(Socket socket, BufferedReader br, PrintWriter pw) {
    
        return new BroadcastHandler(socket, br, pw);
    }
    
    protected boolean isUnique() {
    
        return false;
    }
    
    protected void cleanup() {
    
    }
    
    protected class BroadcastHandler extends ConnectionHandler {
    
        public BroadcastHandler(Socket socket, BufferedReader br, PrintWriter pw) {
        
            super(socket, br, pw);
        }
    
        protected void sayHello() {
        
            synchronized ( temperatureCache ) {
            
                // Tell them what we have
                
                iHave();
            
                // Send the set of available temperatures
        
                for ( Iterator i = temperatureCache.keySet().iterator(); i.hasNext(); ) {
                
                    String address = (String)i.next();
                    Double temperature = (Double)temperatureCache.get(address);
                    
                    send(address + " " + temperature);
                }
            }
        }
        
        /**
         * Send the 'IHAVE' string.
         *
         * This method should be called every time there's an arrival or a
         * departure.
         */
        public void iHave() {
        
            StringBuffer sb = new StringBuffer();
            Set addressSet = null;
            
            sb.append("IHAVE ").append(Integer.toString(deviceSet.size())).append(":");
            
            for ( Iterator i = deviceSet.iterator(); i.hasNext(); ) {
            
                if ( i.hasNext() ) {
                
                    sb.append(" ");
                }
            
                sb.append(i.next().toString());
            }
            
            send(sb.toString());
        }

        protected CommandParser createParser() {
        
            return new BroadcastParser();
        }
        
        protected class BroadcastParser extends CommandParser {
        
            protected void parse2(String line) throws Throwable {
            
                // The broadcaster doesn't really parse anything, all the
                // input is ignored
            }
        }
    }
}