eventwriter.java

Java games programing--很好的java游戏编程源码

package com.hypefiend.javagamebook.server;

import com.hypefiend.javagamebook.common.*;
import java.io.*;
import java.nio.*;
import java.nio.channels.*;
import org.apache.log4j.Logger;

/**
 * EventWriter.java
 *
 * 
 * @author <a href="mailto:[e-mail]">bret barker</a>
 * @version 1.0
 */
public class EventWriter extends Wrap {
    /** reference to the GameServer */
    private static GameServer gameServer;
    
    /** 
     * contructor.
     */
    public EventWriter(GameServer gameServer, int numWorkers) {
	this.gameServer = gameServer;
	initWrap(numWorkers);
    }

    /** 
     * note we override the Wrap's run method here
     * doing essentially the same thing, but 
     * first we allocate a ByteBuffer for this
     * thread to use
     */
    public void run() {
 	ByteBuffer writeBuffer = ByteBuffer.allocateDirect(Globals.MAX_EVENT_SIZE);

	GameEvent event;
	running = true;
	while (running) {
	    try {
		if ((event = eventQueue.deQueue()) != null) {
		    processEvent(event, writeBuffer);
		}
	    }
	    catch(InterruptedException e) {
	    }
	}
    }

    /** unused */
    protected void processEvent(GameEvent event) {
    }

    /** 
     * our own version of processEvent that takes 
     * the additional parameter of the writeBuffer 
     */
    protected void processEvent(GameEvent event, ByteBuffer writeBuffer) {
	NIOUtils.prepBuffer(event, writeBuffer);
	
	String[] recipients = event.getRecipients();
	if (recipients == null) {
	    log.info("writeEvent: type=" + event.getType() + ", id=" + 
		     event.getPlayerId() + ", msg=" + event.getMessage());
	    String playerId = event.getPlayerId();
	    write(playerId, writeBuffer);
	}
	else {
	    for (int i = 0; i < recipients.length; i++) {
		if (recipients[i] != null) {
		    log.info("writeEvent(B): type=" + event.getType() + ", id=" + 
			     recipients[i] + ", msg=" + event.getMessage());
		    write(recipients[i], writeBuffer);
		}
	    }
	}
	
    }
    
    /**
     * write the event to the given playerId's channel
     */
    private void write( String playerId, ByteBuffer writeBuffer) {	
	Player player = gameServer.getPlayerById(playerId);
	SocketChannel channel = player.getChannel();
	
	if (channel == null || !channel.isConnected()) {
	    log.error("writeEvent: client channel null or not connected");
	    return;
	}
	
	NIOUtils.channelWrite(channel, writeBuffer);
    }
    
}// EventWriter