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 1.2 2002/03/04 21:42:57 echtcherbina 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.toString()).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.toString() + ":" + port, ez1);
	    synchronized (this) {
		pendingConnection = false;
		setLastFailed (System.currentTimeMillis());
		socket = null;
		notifyAll();
	    }
	    return;
        }

	// Set the proper setting on the Socket.

	try {
        //PDA requirement 18.02.2002
        //method did not exist in jdk 1.1.8
	    // tmp.setSendBufferSize (TcpConnectionSendBufferSize);
	    tmp.setTcpNoDelay (true);
	    tmp.setSoTimeout (TcpConnectionSoTimeout);
        //PDA requirement 18.02.2002
        // there are no such method in jdk 1.1.8
	    // 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();
    }
}