package examples.patterns;/* * @(#)Watcher.java *  * 03L7246 (c) Copyright IBM Corp. 1996, 1998 *  * The program is provided "as is" without any warranty express or * implied, including the warranty of non-infringement and the implied * warranties of merchantibility and fitness for a particular purpose. * IBM will not be liable for any damages suffered by you as a result * of using the Program. In no event will IBM be liable for any * special, indirect or consequential damages or lost profits even if * IBM has been advised of the possibility of their occurrence. IBM * will not be liable for any third party claims against you. */import com.ibm.aglet.*;import com.ibm.agletx.patterns.*;import com.ibm.aglet.util.*;import java.net.URL;import java.net.MalformedURLException;import java.io.IOException;import java.util.Vector;import java.util.Hashtable;/** * Class Watcher is used to check the update of a file located * in a remote aglet server. Given an URL and a file pathname, it will * dispatch a slave (the WatcherNotifier instance) to 'watch' update of a file. * The slave will not return to the master aglet. While at the remote server, * the slave may dispatch a file update report to the master. This is a part * of the Messenger usage pattern. Watcher is acting as a receiver in * this pattern. *  * @see Watcher * @see WatcherWindow * @version     1.00     96/12/28 * @author      Danny B. Lange * @author      Yoshiaki Mima * @author      Yariv Aridor */public class Watcher extends SampleAglet {	private final static String NotifierClassName = 		"examples.patterns.WatcherNotifier";	private double interval = 0.0;	private double duration = 0.0;	private boolean stay = false;	private String path = "";	protected void createSlave(Vector destinations, Object obj) {		try {			Notifier.create(null, NotifierClassName, getAgletContext(), this, 							(URL)(destinations.firstElement()), interval, 							duration, stay, path);		} catch (IOException ae) {			setTheMessage("Notifier Aglet creation failed...");		} catch (AgletException ae) {			setTheMessage("Notifier Aglet creation failed...");		} 	}	/*	 * public void onCreation (Object o) {	 * super.onCreation(o);	 * try {	 * _msw = new WatcherWindow(this);	 * updateWindow();	 * } catch (Exception e) {	 * inError(e.getMessage());	 * }	 * }	 */	public void createWindow() {		try {			_msw = new WatcherWindow(this);			updateWindow();		} catch (Exception e) {			inError(e.getMessage());		} 	}	/**	 * Creates and sets up the WatcherNotifier with the necessary information to	 * dispatch to a remote aglet server and hopefully stay there successfully.	 * This method is a callback method for the interaction window.	 * @param itinerary contains the destination URL.	 */	protected void go(URL destination, double interval, double duration, 					  boolean stay, String path) {		this.interval = interval;		this.duration = duration;		this.stay = stay;		this.path = path;		super.go(destination);	}	public boolean handleMessage(Message msg) {		if (msg.sameKind("notification")) {			message((Arguments)(msg.getArg()));		} else {			super.handleMessage(msg);		}		return true;	}	/**	 * Implements the message interface of a receiver. This method is	 * a part of the Messenger usage pattern.	 * @Messenger m Messanger aglet that has returened from a slave aglet.	 * @Object message Message returned.	 */	private synchronized void message(Arguments message) {		int type = ((Integer)message.getArg("type")).intValue();		if (type == Notifier.NOTIFICATION) {			_msw.appendResult("UPDATE: " 							  + (String)(message.getArg("message")) 							  + ", AT: " + message.getArg("date").toString());		} else {			setTheMessage((String)(message.getArg("message")));		} 	}}