terminatenaplet.java~

移动Agent编程工具Naplet

/* 
 * @<#> TerminateNaplet.java version 0.0.1, 1/1/2000
 *
 * THIS PROGRAM IS FREE SOFTWARE; YOU CAN DISTRIBUTE IT AND/OR
 * MODIFY IT UNDER THE TERMS OF THE GNU GENERAL PUBLIC LICENSE 
 * AS PUBLISHED BY THE FREE SOFTWARE FOUNDATION.
 *
 * THIS PROGRAM IS DISTRIBUTED IN THE HOPE THAT IT WILL BE USEFUL,
 * BUT WITHOUT ANY WARRANTY; WITHOUT EVEN THE IMPLIED WARRANTY OF
 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. SEE THE 
 * GNU GENERAL PUBLIC LICENSE FOR MORE DETAILS.
 *
 * Copyright (c) 2000 Wayne State University. All Rights Reserved.
 */

package terminate;


/**
 * The <code>TerminateNaplet</code> class implements a dummy naplet 
 * that travels around the network, sleeping a while at each server.
 * The naplet will be terminated by its dispatcher.
 *
 * @version 0.0.1, 1/1/2000
 * @author C. Xu
 *
 */
import java.io.*;
import java.rmi.*;
import java.util.*;
import java.lang.reflect.*;

import naplet.*;
import naplet.itinerary.*;
import naplet.message.*;

public class TerminateNaplet extends Naplet {

	public TerminateNaplet(String[] servers)
				throws InvalidNapletException, InvalidItineraryException {
		this(null, servers, null);
	}

	public TerminateNaplet(String name, String[] servers) 
				throws InvalidNapletException, InvalidItineraryException {
		this(name, servers, null);
	}

	/**
	 * Constructs a naplet
	 * @param servers a list of servers to be visited
	 * @param listener listener of the naplet waiting for results
	 */
	public TerminateNaplet(String[] servers, NapletListener listener) 
					throws InvalidNapletException, InvalidItineraryException {
		this(null, servers, listener);
	}

	/**
	 * Constructs a naplet, setting itinerary 
	 * 
	 * @param name Nick name of the naplet
	 * @param servers A list of servers to be visitted
	 * @param listener Listener of the naplet waiting for results
	 */
	public TerminateNaplet(String name, String[] servers, NapletListener listener) 
			throws InvalidNapletException, InvalidItineraryException {

		super(name, listener); 
		try {
			Hashtable messages = new Hashtable( servers.length );
        	setNapletState( new ProtectedNapletState() );
        	getNapletState().set("message", messages);
		} catch (NapletStateAccessException nsae) {
			throw new InvalidNapletException("Naplet state initialization failure");
		}
	
		setItinerary ( new ICItinerary( servers ) );

	}

	/**
	 * Entry point of a naplet at each server
	 */
	public void onStart() throws InterruptedException {
		String serverName;
			
		serverName = getNapletContext().getServerURN().getHostName();

		System.out.println( "Naplet " + this.getNapletID().toString() 
 							+ " arrives at " + serverName);
			
		System.out.println("Sleeping... ...");
		Thread.sleep(30000);
		System.out.println("Wakeup");

		try {
			getItinerary().travel( this );
		} catch (NapletMigrateException nme) {
			System.out.println(nme.getMessage());
		}

		System.out.println("End of Start()");
	}

	public void onInterrupt() {
	    MailBox mbox = this.getNapletContext().getMessenger().getMailBox(this.getNapletID());
	    try {
	        Message msg = mbox.getMessage();
	        switch (msg.getType()) {
	            case Message.TERMINATE:
					System.out.println("I'm to be interrupted");
					Message ack = new Message(Message.TERMINATE_ACK, 
						this.getNapletID(), msg.getSender(), " Ack to terminate");
					try {
						this.getNapletContext().getMessenger().send(this.getNapletID(), msg.getSender(), ack);

					} catch (NapletCommunicationException nce) {
						System.out.println(nce.getMessage());
					}

	              Thread.currentThread().interrupt();
	            case Message.SUSPEND:
	            case Message.RESUME:
	        }
	    } catch (InterruptedException ie){}
	}

	static void classFinalize() {
		System.out.println("MyNaplet was finalized");
	}

	private class ICItinerary extends Itinerary {

		public ICItinerary( String[] servers ) 
				throws InvalidItineraryException {


			Operable act = null; 

			// seq(s0,s1,s2) 
			setRoute( new SeqPattern(servers, act) );	

			System.out.println("ICItinerary = " + getRoute().toString() );

		}


    }

}