httpclient.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.AdminRequest;
import gov.lbl.dsd.sea.nio.event.ChannelRequest;
import gov.lbl.dsd.sea.nio.event.ChannelResponse;
import gov.lbl.dsd.sea.nio.util.ArrayByteList;

import java.io.IOException;
import java.net.InetSocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.SelectionKey;
import java.nio.charset.Charset;

/**
 * Simple echo client; connects to one or more HTTP servers and prints page
 * output.
 * <p>
 * Example usage: fire-java gov.lbl.dsd.sea.nio.demo.HttpClient localhost:8080 www.google.com:80 localhost:9999
 * 
 * @author [e-mail]
 * @author $Author: gegles $
 * @version $Revision: 1.5 $, $Date: 2004/09/16 16:57:15 $
 */
public class HttpClient extends AgentEventHandler {

	private static final Charset CHARSET = Charset.forName("ISO-8859-1");
	private int nrChannels = 0;

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

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

	public HttpClient(String args[]) throws IOException {
		NetAgent agent = new NetAgent();
		Stage myStage = new StageManager().createStage(this).start();

		if (args.length < 1) throw new IllegalArgumentException("usage: java <class> host:port...");
		for (int i=0; i < args.length; i++) {
			int delim = args[i].indexOf(":");
			if (delim < 0) throw new IllegalArgumentException("usage: java <class> host:port...");
			String hostName = args[i].substring(0, delim); 
			int port = Integer.parseInt(args[i].substring(delim+1, args[i].length()));
			agent.addConnectAddress(myStage, new InetSocketAddress(hostName, port));
			this.nrChannels++;
		}

		agent.start();
	}

	protected void onClosed(ChannelResponse.Closed rsp) {
		log.info("*************got channel closed=" + rsp);
		if (rsp.getException() != null) {
			log.error(rsp.getException());
		}
		ArrayByteList readBuffer = (ArrayByteList) rsp.getKey().attachment();
		if (readBuffer != null) {
			System.out.println("*** fully read bytes  = " + readBuffer);		
			System.out.println("*** fully read string = " + readBuffer.toString(CHARSET));
		}
		if (--nrChannels == 0) {
			this.shutDown(rsp);
		}
	}

	protected void onConnected(ChannelResponse.Connected rsp) {
		log.info("*************got connected=" + rsp);
		rsp.getKey().attach(new ArrayByteList());
		rsp.getAgent().enqueue(
				new ChannelRequest.Register(this.getStage(), rsp.getKey()
						.channel(), SelectionKey.OP_READ));
		ByteBuffer buffer = new ArrayByteList("GET / HTTP/1.0" + "\r\n" + "\r\n", CHARSET).asByteBuffer();
		rsp.getAgent().enqueue(
				new ChannelRequest.WriteData(rsp.getKey().channel(), buffer));
	}

	protected void onRead(ChannelResponse.Read rsp) {
		ArrayByteList readBuffer = (ArrayByteList) rsp.getKey().attachment();
		readBuffer.add(rsp.getBuffer());		
	}

	protected void onAccepted(ChannelResponse.Accepted rsp) {
		throw new UnsupportedOperationException();
	}

	protected void onWrite(ChannelResponse.Write rsp) {}

	protected void onRegistered(ChannelResponse.Registered rsp) {}

	private void shutDown(ChannelResponse rsp) {
		System.out.println("now shutting down...");
		this.getStage().stop();
		rsp.getAgent().enqueue(new AdminRequest.Stop());
	}

}