tcpsocket.java

jxme的一些相关程序,主要是手机上程序开发以及手机和计算机通信的一些程序资料,程序编译需要Ant支持

/*
 *
 * $Id: TcpSocket.java,v 1.9 2002/06/11 19:26:39 hamada Exp $
 *
 * Copyright (c) 2001 Sun Microsystems, Inc.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *       Sun Microsystems, Inc. for Project JXTA."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA"
 *    must not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact Project JXTA at http://www.jxta.org.
 *
 * 5. Products derived from this software may not be called "JXTA",
 *    nor may "JXTA" appear in their name, without prior written
 *    permission of Sun.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL SUN MICROSYSTEMS OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of Project JXTA.  For more
 * information on Project JXTA, please see
 * <http://www.jxta.org/>.
 *
 * This license is based on the BSD license adopted by the Apache Foundation.
 */


package net.jxta.impl.endpoint.tcp;

import java.net.*;
import java.io.*;
import java.util.*;
import org.apache.log4j.Category; 
import org.apache.log4j.Priority;

import net.jxta.document.MimeMediaType;
import net.jxta.endpoint.*;

import net.jxta.impl.endpoint.MessageImpl;
import net.jxta.impl.endpoint.MessageWireFormat;
import net.jxta.impl.endpoint.MessageWireFormatFactory;


/**
 * Low-level TcpSocket management
 *
 * @since       JXTA 1.0
 */

public class TcpSocket implements Runnable {

	private static final Category LOG = Category.getInstance(TcpSocket.class.getName());
	private static final int TcpConnectionSendBufferSize = 64 * 1024; // 64 KBytes
	private static final int TcpConnectionSoTimeout = 30 * 1000; // 30 Seconds
	private static final int FailureDelay = 10 * 60 * 1000; // 10 Minutes

	private InetAddress inetAddress = null;
	private int port = 0;
	private long lastOpened = 0;
	private long lastFailed = 0;
	private Socket socket = null;
	private boolean pendingConnection = false;
	private boolean activity = false;

	public TcpSocket (InetAddress inetAddress, int port) {
		this.inetAddress = inetAddress;
		this.port = port;
		connect();
	}

	public TcpSocket() {
	}

	public synchronized Socket getSocket (long timeout) {

		if (socket != null) {
			return socket;
		}

		connect();

		if (pendingConnection) {

			try {
				wait (timeout);
			} catch (InterruptedException e) {
				return socket;
			}
		}
		return socket;
	}

	public synchronized void setSocket (Socket socket) {
		this.socket = socket;
	}

	public synchronized long getLastOpened () {
		return lastOpened;
	}

	public synchronized void setLastOpened(long time) {
		lastOpened = time;
	}

	public synchronized long getLastFailed () {
		return lastFailed;
	}

	public synchronized void setLastFailed(long time) {
		lastFailed = time;
	}

	private void connect () {

		boolean doConnect = false;

		synchronized (this) {

			if (pendingConnection) {
				// There is already a thread trying to connect. Nothing to do.
				return;
			}
			if ((lastOpened == 0) || (lastFailed == 0) || activity) {
				if (activity) {
					activity = false;
				}
				// This is the first time we try to open a socket to remote host.
				doConnect = true;
			} else {
				if (lastOpened > lastFailed) {
					// The last attempt was successful. We should try to reconnect.
					doConnect = true;
				} else {
					// The last attempt failed. Would it be time to try again ?
					if ((lastFailed + FailureDelay) <= System.currentTimeMillis()) {
						doConnect = true;
					}
				}
			}
			if (!doConnect) {
				// Nothing to do.
				return;
			}

			// Attempt a new connection.
			pendingConnection = true;
			new Thread(this, "TcpSocket open Socket for " + inetAddress.getHostAddress()).start();
		}

		Thread.yield();
	}

	public void run() {

		Socket tmp = null;
		try {
			tmp = new Socket(inetAddress, port);
		} catch (IOException ez1) {
			if (LOG.isEnabledFor(Priority.DEBUG)) 
			    LOG.debug("Cannot open socket for " +
				        inetAddress.getHostAddress() + ":" + port, ez1);
			synchronized (this) {
				pendingConnection = false;
				setLastFailed (System.currentTimeMillis());
				socket = null;
				notifyAll();
			}
			return;
		}

		// Set the proper setting on the Socket.

		try {
			tmp.setSendBufferSize (TcpConnectionSendBufferSize);
			tmp.setTcpNoDelay (true);
			tmp.setSoTimeout (TcpConnectionSoTimeout);
			tmp.setKeepAlive (true);
		} catch (Exception ez1) {
			if (LOG.isEnabledFor(Priority.ERROR)) LOG.error("Cannot set socket options", ez1);
			try {
				tmp.close();
			} catch (Exception ez2) {
				if (LOG.isEnabledFor(Priority.ERROR)) 
				    LOG.error("Cannot close socket.", ez2);
			}
			synchronized (this) {
				setLastFailed (System.currentTimeMillis());
				socket = null;
				pendingConnection = false;
				notifyAll();
			}
			return;
		}

		synchronized(this) {
			socket = tmp;
			setLastOpened (System.currentTimeMillis());
			pendingConnection = false;
			notifyAll();
		}
	}

	public synchronized void close() {

		if (pendingConnection) {
			try {
				wait();
			} catch (InterruptedException ez1) {
				if (LOG.isEnabledFor(Priority.ERROR)) LOG.error("Interrupted. Cannot close socket.", ez1);
			}
		}

		if (socket != null) {
			try {
				socket.close();
			} catch (Exception ez1) {
				if (LOG.isEnabledFor(Priority.ERROR)) LOG.error("Cannot close socket.", ez1);
			}
		}
		socket = null;
	}

	public synchronized void notifyActivity() {
		activity = true;
	}

	public void finalize() {
		close();
	}
}