simplehttpdemo.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.demo;

import gov.lbl.dsd.sea.EventHandler;
import gov.lbl.dsd.sea.Stage;
import gov.lbl.dsd.sea.StageManager;
import gov.lbl.dsd.sea.event.IllegalEventException;

import org.apache.commons.httpclient.HttpMethod;
import org.apache.commons.httpclient.methods.GetMethod;

import EDU.oswego.cs.dl.util.concurrent.CountDown;

/**
 * Demonstrates how to use the HTTP framework with a very basic example. In this
 * example there are two stages. The first stage handles the HTTP transport
 * requests and responses. It hands the responses to the second stage, which
 * simply prints them.
 * <p>
 * Example usage: java gov.lbl.dsd.seda.demo.SimpleHTTPDemo 2 http://www.google.com
 * 
 * @author [e-mail]
 * @author $Author: gegles $
 * @version $Revision: 1.5 $, $Date: 2004/09/16 16:57:15 $
 */
public class SimpleHTTPDemo {
	
	public static void main(String[] args) {
		int k=0;

		int runs = 2;
		if (args.length > k) runs = Integer.parseInt(args[k++]);
		
		String url = "http://www.google.com";
		//String url = "http://dsd.lbl.gov/firefish/usages/fire-grep-usage.txt";
		//String url = "http://localhost:8080/firefish/HelloWorldServlet";
		//String url = "http://localhost:8080/firefish/index.html";
		if (args.length > k) url = args[k++];

		final CountDown barrier = new CountDown(runs); // a barrier to later wait until all responses have arrived
		
		// an event handler that simply prints the HTTP response
		EventHandler handler = new EventHandler() {
			public void handle(Object object) {
				System.out.println("**************** RESPONSE *****************************");
				if (object instanceof ByteArrayEvent) {
					ByteArrayEvent ev = (ByteArrayEvent) object;
					String str = new String(ev.getBytes());
					System.out.println(str);
					barrier.release(); // signal that a response has arrived
				}
				else {
					throw new IllegalEventException(object, this.getStage());
				}
			}
		};
		StageManager manager = new StageManager();
		final Stage s2 = manager.createStage(handler).start();

		final Stage s1 = manager.createStage(new SimpleHTTPEventHandler(s2)).start();
		
		long start = System.currentTimeMillis();
		try {
			// s1.enqueue(new Integer(-1)); // try this to get IllegalEventExceptions
			for (int i = 0; i < runs; i++) {
				HttpMethod method = new GetMethod(url);
				s1.enqueue(method);
			}
			
			try {
				// wait until all HTTP responses have arrived [via
				// barrier.release()]; and only then shutdown
				barrier.acquire();
			} catch (InterruptedException e) {}
			
			long end = System.currentTimeMillis();
			System.out.println("total time (ms): " + (end - start));
			System.out.println("time (ms) per request: " + ((end - start) / (runs * 1.0f)));

		} finally {
			// cleanly shut down all stages and threads
			System.out.println("now shutting down...");
			manager.stopAll();
		}
	}
}