timeserver.java

sea是一个基于seda模式的实现。这个设计模式将系统分为很多stage。每个stage分布不同的任务（基于线程池）。通过任务流的方式提高系统的效率。

/*
 * Copyright (c) 2003, The Regents of the University of California, through
 * Lawrence Berkeley National Laboratory (subject to receipt of any required
 * approvals from the U.S. Dept. of Energy). All rights reserved.
 */
package gov.lbl.dsd.sea.nio.demo;

import gov.lbl.dsd.sea.Stage;
import gov.lbl.dsd.sea.StageManager;
import gov.lbl.dsd.sea.nio.AgentEventHandler;
import gov.lbl.dsd.sea.nio.NetAgent;
import gov.lbl.dsd.sea.nio.event.ChannelRequest;
import gov.lbl.dsd.sea.nio.event.ChannelResponse;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.channels.SocketChannel;
import java.nio.charset.Charset;
import java.util.Date;

/**
 * Simple time server that can be tested in
 * conjunction with a standard UNIX telnet client.
 * 
 * @author [e-mail]
 * @author $Author: gegles $
 * @version $Revision: 1.4 $, $Date: 2004/09/16 16:57:15 $
 */
public class TimeServer extends AgentEventHandler {
	
	private static final Charset CHARSET = Charset.forName("US-ASCII");

	private static final org.apache.commons.logging.Log log = org.apache.commons.logging.LogFactory
			.getLog(TimeServer.class);

	static public void main(String args[]) throws IOException {
		new TimeServer(args);
	}

	public TimeServer(String args[]) throws IOException {
		NetAgent agent = new NetAgent();

		Stage myStage = new StageManager().createStage(this).start();

		for (int i = 0; i < args.length; i++) {
			int port = Integer.parseInt(args[i]);		
			agent.addListenPort(myStage, port);
		}

		agent.start();
	}

	protected void onClosed(ChannelResponse.Closed rsp) {
		log.info("*************got channel closed=" + rsp);
		if (rsp.getException() != null) {
			; // nothing special to be done
		}
	}

	protected void onConnected(ChannelResponse.Connected rsp) {
		throw new UnsupportedOperationException();
	}

	protected void onRead(ChannelResponse.Read rsp) {
		throw new UnsupportedOperationException();
	}

	protected void onAccepted(ChannelResponse.Accepted rsp) {
		rsp.getAgent().enqueue(
				new ChannelRequest.WriteData(rsp.getKey()
						.channel(), createResponse((SocketChannel) rsp.getKey().channel())));
	}

	protected void onWrite(ChannelResponse.Write rsp) {
		rsp.getAgent().enqueue(new ChannelRequest.Close(rsp.getKey().channel()));

		rsp.getBuffer().flip();
		System.out.println("******************** wrote *********** "
				+ CHARSET.decode(rsp.getBuffer()).toString());
		// recycling to buffer pool is an optional optimization
		rsp.getAgent().getReadBufferPool().put(rsp.getBuffer());		
	}

	protected void onRegistered(ChannelResponse.Registered rsp) {
		if (rsp.getInterestOps() == SelectionKey.OP_ACCEPT) {
			System.out.println("******** server started; now listening *****");
		}
	}

	protected ByteBuffer createResponse(SocketChannel channel) {
		Date now = new Date();
		ByteBuffer buffer = CHARSET.encode(now + "\r\n");
		System.out.println("Response to " + channel.socket().getInetAddress() + " = " + now);
		return buffer;
	}
		
}