SocketSessionHandler.java

/*
 * Copyright (C) 2006-2008 Alfresco Software Limited.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.

 * 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.

 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

 * As a special exception to the terms and conditions of version 2.0 of 
 * the GPL, you may redistribute this Program in connection with Free/Libre 
 * and Open Source Software ("FLOSS") applications as described in Alfresco's 
 * FLOSS exception.  You should have recieved a copy of the text describing 
 * the FLOSS exception, and it is also available here: 
 * http://www.alfresco.com/legal/licensing"
 */

package org.alfresco.jlan.server;

import java.io.IOException;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketException;

import org.alfresco.jlan.debug.Debug;

/**
 * Socket Session Handler Class
 * 
 * <p>
 * Implementation of a session handler that uses a Java socket to listen for incoming session
 * requests.
 * 
 * @author gkspencer
 */
public abstract class SocketSessionHandler extends SessionHandlerBase implements Runnable {

	// Server socket to listen for incoming connections

	private ServerSocket m_srvSock;

	// Client socket read timeout
	
	private int m_clientSockTmo;
	
	/**
	 * Class constructor
	 * 
	 * @param name String
	 * @param protocol String
	 * @param server NetworkServer
	 * @param addr InetAddress
	 * @param port int
	 */
	public SocketSessionHandler(String name, String protocol, NetworkServer server, InetAddress addr, int port) {
		super(name, protocol, server, addr, port);
	}

	/**
	 * Return the server socket
	 * 
	 * @return ServerSocket
	 */
	public final ServerSocket getSocket() {
		return m_srvSock;
	}

	/**
	 * Return the client socket timeout, in milliseconds
	 * 
	 * @return int
	 */
	public final int getSocketTimeout() {
		return m_clientSockTmo;
	}

	/**
	 * Set the client socket timeout, in milliseconds, zero for no timeout
	 * 
	 * @param tmo int
	 */
	public final void setSocketTimeout(int tmo) {
		m_clientSockTmo = tmo;
	}
	
	/**
	 * Initialize the session handler
	 * 
	 * @param server NetworkServer
	 */
	public void initializeSessionHandler(NetworkServer server)
		throws IOException {

		// Open the server socket

		if ( hasBindAddress())
			m_srvSock = new ServerSocket(getPort(), getListenBacklog(), getBindAddress());
		else
			m_srvSock = new ServerSocket(getPort(), getListenBacklog());

		// Set the allocated port

		if ( getPort() == 0)
			setPort(m_srvSock.getLocalPort());

		// DEBUG

		if ( Debug.EnableInfo && hasDebug()) {
			Debug.print("[" + getProtocolName() + "] Binding " + getHandlerName() + " session handler to address : ");
			if ( hasBindAddress())
				Debug.println(getBindAddress().getHostAddress());
			else
				Debug.println("ALL");
		}
	}

	/**
	 * Close the session handler
	 * 
	 * @param server NetworkServer
	 */
	public void closeSessionHandler(NetworkServer server) {

		// Request the main listener thread shutdown

		setShutdown( true);

		try {

			// Close the server socket to release any pending listen

			if ( m_srvSock != null)
				m_srvSock.close();
		}
		catch (SocketException ex) {
		}
		catch (Exception ex) {
		}
	}

	/**
	 * Socket listener thread
	 */
	public void run() {

		try {

			// Clear the shutdown flag

			clearShutdown();

			// Wait for incoming connection requests

			while (hasShutdown() == false) {

				// Debug

				if ( Debug.EnableInfo && hasDebug())
					Debug.println("[" + getProtocolName() + "] Waiting for session request ...");

				// Wait for a connection

				Socket sessSock = m_srvSock.accept();

				// Debug

				if ( Debug.EnableInfo && hasDebug())
					Debug.println("[" + getProtocolName() + "] Session request received from "
							+ sessSock.getInetAddress().getHostAddress());

				try {

					// Process the new connection request

					acceptConnection(sessSock);
				}
				catch (Exception ex) {

					// Debug

					if ( Debug.EnableInfo && hasDebug())
						Debug.println("[" + getProtocolName() + "] Failed to create session, " + ex.toString());
				}
			}
		}
		catch (SocketException ex) {

			// Do not report an error if the server has shutdown, closing the server socket
			// causes an exception to be thrown.

			if ( hasShutdown() == false) {
				Debug.println("[" + getProtocolName() + "] Socket error : " + ex.toString());
				Debug.println(ex);
			}
		}
		catch (Exception ex) {

			// Do not report an error if the server has shutdown, closing the server socket
			// causes an exception to be thrown.

			if ( hasShutdown() == false) {
				Debug.println("[" + getProtocolName() + "] Server error : " + ex.toString());
				Debug.println(ex);
			}
		}

		// Debug

		if ( Debug.EnableInfo && hasDebug())
			Debug.println("[" + getProtocolName() + "] " + getHandlerName() + " session handler closed");
	}

	/**
	 * Accept a new connection on the specified socket
	 * 
	 * @param sock Socket
	 */
	protected abstract void acceptConnection(Socket sock);
}