org.rifidi.emulator.io.comm.ip.udp.UDPOffCommunicationPowerState.java Source code

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Here is the source code for org.rifidi.emulator.io.comm.ip.udp.UDPOffCommunicationPowerState.java

Source

/*
 *  UDPOffCommunicationPowerState.java
 *
 *  Project:      RiFidi Emulator - A Software Simulation Tool for RFID Devices
 *  http://www.rifidi.org
 *  http://rifidi.sourceforge.net
 *  Copyright:       Pramari LLC and the Rifidi Project
 *  License:      Lesser GNU Public License (LGPL)
 *  http://www.opensource.org/licenses/lgpl-license.html
 */
package org.rifidi.emulator.io.comm.ip.udp;

import java.io.IOException;
import java.net.DatagramSocket;
import java.net.InetSocketAddress;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.rifidi.emulator.common.PowerControllable;
import org.rifidi.emulator.io.comm.buffered.BufferedOffCommunicationPowerState;

/**
 * This represents the "off" state for the communication module.  It can be
 * turned on.  
 * 
 * @author Matthew Dean - matt@pramari.com
 * @since <$INITIAL_VERSION$>
 * @version <$CURRENT_VERSION$>
 *
 */
public class UDPOffCommunicationPowerState extends BufferedOffCommunicationPowerState {

    /**
     * Message logger
     */
    private static Log logger = LogFactory.getLog(UDPCommunicationIncomingMessageHandler.class);

    /**
     * The singleton instance for this state.
     */
    private static final UDPOffCommunicationPowerState SINGLETON_INSTANCE = new UDPOffCommunicationPowerState();

    /**
     * A default-access method for getting the singleton instance of this state
     * class. The default access is designed so that only other members of the
     * UDP package may use this class.
     * 
     * @return The singleton instance of this state class.
     */
    static UDPOffCommunicationPowerState getInstance() {
        return UDPOffCommunicationPowerState.SINGLETON_INSTANCE;
    }

    /**
     * A private constructor used for making the singleton instance of this
     * class.
     */
    private UDPOffCommunicationPowerState() {
        /* Do nothing special, no class variables are being used. */
    }

    /** 
     * Calls the method in the superclass and kicks off the threads making 
     */
    @Override
    public void turnOn(PowerControllable pcObject) {
        logger.debug("Turning on...");

        /* Invoke buffered handlers. */
        super.turnOn(pcObject);

        /* Cast the passed PowerControllable to a UDPCommmunication. */
        UDPCommunication curUDPComm = (UDPCommunication) pcObject;

        /* Get the Datagram object from the communication object. */
        DatagramSocket tempSocket = curUDPComm.getDatagramSocket();

        /* bind the udp communication object to the local address
         * this is the from address in a message */
        try {
            tempSocket.bind(new InetSocketAddress(curUDPComm.getLocalIPAddress(), curUDPComm.getLocalPort()));
        } catch (IOException e) {
            logger.warn(e.getMessage());
        }

        /* If we are only doing output then we do not need an incoming
         * message handler for udp */
        if (!curUDPComm.isOutputOnly()) {
            new Thread(new UDPCommunicationIncomingMessageHandler(curUDPComm), "Incoming Message Handler").start();
        }

        /* We will always have an outgoing UDP message handler to send
         * udp messages to the remote address */
        new Thread(new UDPCommunicationOutgoingMessageHandler(curUDPComm), "Outgoing Message Handler").start();

        /* Change to the on state */
        curUDPComm.changePowerState(UDPOnCommunicationPowerState.getInstance());

    }

}