serverresponsereader.java

一个基于J2ME技术的程序,使你可以远程控制装有服务端的PC.

/*
 * JRemCntl - Copyright (C) 2007 Filippo Di Vattimo <[e-mail]>
 * See COPYING
 */

package fildiv.jremcntl.client.core;

import java.io.IOException;
import java.util.Vector;

import fildiv.jremcntl.common.proto.JRemProtocolMessagesType;

public class ServerResponseReader {

	private JRemClientProtocol proto;

	private Vector listeners;

	private Thread theThread;

	private boolean exit;

	public ServerResponseReader(JRemClientProtocol proto,
			ServerResponseListener listener) {

		this.proto = proto;
		listeners = new Vector();

		addServerResponseReaderListener(listener);

		theThread = new Thread() {

			public void run() {
				listen();
			}
		};

		theThread.start();
	}

	public void addServerResponseReaderListener(ServerResponseListener listener) {

		listeners.addElement(listener);
	}

	public void removeServerResponseReaderListener(
			ServerResponseListener listener) {

		listeners.removeElement(listener);
	}
	
	private void fireConnectionClosed() {

		for (int index = 0; index < listeners.size(); ++index) {
			ServerResponseListener l = (ServerResponseListener) listeners
					.elementAt(index);
			l.connectionClosed();
		}
	}

	private void fireConnectionLost() {

		for (int index = 0; index < listeners.size(); ++index) {
			ServerResponseListener l = (ServerResponseListener) listeners
					.elementAt(index);
			l.connectionLost();
		}
	}

	private void fireReceivedCommandResponse(ServerResponse response) {

		for (int index = 0; index < listeners.size(); ++index) {
			ServerResponseListener l = (ServerResponseListener) listeners
					.elementAt(index);
			l.receivedCommandResponse(response);
		}
	}

	public synchronized void close() {
		
		if (exit)
			return;
		
		exit = true;
		
		if (theThread == null)
			return;
		
		synchronized (theThread) {
			try {
				// wait for a bit and interrupts the thread
				
				theThread.wait(3000);
				theThread.interrupt();
				
			} catch (Exception e) {
				// Nothing
			}
		}
	}

	private void listen() {

		try {

			while (!exit) {

				ServerResponse sr = proto.retrieveServerResponse();
				
				if (sr != null) {
					switch (sr.getType()) {
					case JRemProtocolMessagesType.MSG_TYPE_CLOSE_CONNECTION:
						exit = true;
						fireConnectionClosed();						
						break;
					case JRemProtocolMessagesType.MSG_TYPE_SEND_COMMAND_RESULT:
						fireReceivedCommandResponse(sr);
						break;
	
					default:
						break;
					}
				}
				
				theThread.sleep(50);
			}

		} catch (IOException e) {
			
			if (!exit)
				fireConnectionLost();
		
		} catch (InterruptedException e) {
			// fall in from close method
		} catch(Exception e) {
			// Never fall in (I hope! :) )		
		} finally {
						
			synchronized (theThread) {
				theThread.notify();
				theThread = null;
			}
		}
	}
}