tcpconnection.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: TcpConnection.java,v 1.15 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.EndpointReceiveQueue;
import net.jxta.impl.endpoint.MessageWireFormat;
import net.jxta.impl.endpoint.MessageWireFormatFactory;


/**
 * Low-level TcpMessenger
 *
 * @since       JXTA 1.0
 */

public class TcpConnection implements Runnable {
	private static final Category LOG = Category.getInstance(TcpConnection.class.getName());
	public static final int MaxNbOfMessages = 40;

	private InetAddress inetAddress = null;
	private int port = 0;
	private TcpTransport proto = null;
	private Header header = null;
	private TcpSocket tcpSocket = null;
	private boolean waiting = false;
	private EndpointAddress dstAddress = null;
	private long lastUsed = 0;
	private String dstAddrString = null;
	private Thread thread = null;
	private EndpointReceiveQueue queue = null;
	private long nbOfMessagesSent = 0;
	private MimeMediaType appMsg = new MimeMediaType( "application/x-jxta-msg");
	public TcpConnection (EndpointAddress destaddr,
	                      TcpTransport p)
	throws IOException {

		// Not much has to be done: the connection with the remote node
		// will happen only when the data will be sent.
		if (LOG.isEnabledFor(Priority.DEBUG))
			LOG.debug("Constructor\n   addr = " + destaddr.toString());

		header = new Header();
		proto = p;

		this.dstAddress = (EndpointAddress) destaddr.clone();
		try {
			String tmp = destaddr.getProtocolAddress();
			int portIndex = tmp.indexOf(":");
			if (portIndex == -1) {
				throw new IOException("Invalid EndpointAddress" + tmp);
			}
			port = Integer.valueOf(tmp.substring(portIndex + 1)).intValue();
			inetAddress = InetAddress.getByName(tmp.substring(0, portIndex));
			dstAddrString = inetAddress.getHostAddress();
			if (LOG.isEnabledFor(Priority.DEBUG))
				LOG.debug("Constructor using: " + inetAddress.getHostAddress());
		} catch (Exception e) {
			if (LOG.isEnabledFor(Priority.INFO))
				LOG.info("Bad address " + destaddr.toString(), e);
			throw new IOException("Bad address " + destaddr.toString());
		}

		tcpSocket = new TcpSocket (inetAddress, port);
	}


	// Try to connect. This operation is idempotent.
	private void connect () {

		synchronized (this) {
			if (queue == null) {
				// There is new queue. Create one.
				queue = new EndpointReceiveQueue();
				queue.setMaxNbOfMessages (MaxNbOfMessages);
			}

			// Start the background thread.
			if (thread != null) {
				// Nothing to do
				return;
			}
			thread = new Thread (this, "TCP Connection to " + dstAddrString + " [Unused]");
			thread.start();
		}
		Thread.yield();
	}

	private synchronized void setThreadName () {

		if (thread != null) {
			try {
				thread.setName ("TCP Connection to " + dstAddrString + " [" +
				                queue.getNbOfQueuedMessages() + ", " +
				                nbOfMessagesSent + ", " +
				                (isConnected() ? "Connected" : "Disconnected") +
				                " ]");
			} catch (Exception ez1) {
				if (LOG.isEnabledFor(Priority.ERROR))
					LOG.error("Cannot change thread name", ez1);
			}
		}
	}


	// Public method that sends messages to the remote peer.
	// Only queue the message and let the background thread actually sends the message.

	public void sendMessage (Message msg) throws IOException {

		// Try to get a Socket just to check that a connection is possible.
		if ( tcpSocket.getSocket (5000) == null) {
			if (LOG.isEnabledFor(Priority.DEBUG)) {
				LOG.debug("sendMessage() cannot get a socket for " + dstAddrString);
			}
			throw new IOException("sendMessage() cannot get a socket for " + dstAddrString);
		}

		connect();
		// Queue the message.
		synchronized (this) {
			queue.push (msg);
			setThreadName();
		}
		Thread.yield();
	}


	// This is the background Thread. While the connection is active, takes
	// messages from the queue and send it.
	public void run() {

		Message msg = null;
		while (true) {

			try {
				// Wait for messages to be sent.
				msg = queue.waitForMessage();
				if (msg == null) {
					// If the message is null, the queue has been closed.
					thread = null;
					return;
				}
				setThreadName();
				// Send the message.
				doSendMessage (msg);

			} catch (InterruptedException ez1) {
				// The connection is just being close. This Thread must exit.
				thread = null;
				return;
			} catch (IOException ez2) {
				// The message failed. Notify the failure
				notifyFailure();
				thread = null;
				return;
			}
		}
	}

	/**
	 * Send a TransportMessage onto that link.
	 *
	 * @param message TransportMessage to be sent.
	 */
	private void doSendMessage(Message message) throws IOException {

		if (dstAddress == null) {
			if (LOG.isEnabledFor(Priority.WARN))
				LOG.warn("sendMessage: no destination address");
			throw new IOException( "sendMessage: no destination address" );
		}

		if (LOG.isEnabledFor(Priority.DEBUG))
			LOG.debug("sendMessage\n     to = " + dstAddress.toString());

		// Build the protocol header
		// Allocate a buffer to contain the message and the header

		ByteArrayOutputStream baos = new ByteArrayOutputStream();
		MessageWireFormatFactory.newMessageWireFormat(
		    new MimeMediaType( "application/x-jxta-msg" ) )
		.writeMessage(baos, message);
		baos.close();
		byte bytes[] = baos.toByteArray();

		Vector msgBuffers = new Vector();

		msgBuffers.addElement( new byte[header.length] );
		msgBuffers.addElement( bytes );

		// First build the header
		header.cmd = Header.UNICAST;

		header.srcAddr = proto.usingInterface.getAddress();
		header.srcPort = proto.serverSocketPort;
		header.option = Header.NONBLOCKING;
		header.size = bytes.length;

		header.buildForNetwork( (byte []) msgBuffers.elementAt(0), 0);

		int retryAttempt = 0;
		boolean success = false;

		while ( retryAttempt < 2 ) {
			// Open a socket with the destination and send the message
			Socket socket = tcpSocket.getSocket(5000);
			if (socket == null) {
				if (LOG.isEnabledFor(Priority.WARN)) {
					LOG.warn("sendMessage() cannot get a socket for " + dstAddress.toString());
				}
				throw new IOException("sendMessage() cannot get a socket for " + dstAddress.toString());
			}
			try {
				OutputStream outputStream = socket.getOutputStream();
				InputStream ip = socket.getInputStream();

				if (retryAttempt == 0) {
					// Drain the back channel, just in case some keep alive
					// hint is hanging there. Use the last one we find.
					// Normaly the hint arrives too late for use at the end
					// of transmission and we do not want to wait for it. The hint
					// never arrives before we send something. As a result, we
					// can always assume that we get that hint at the begining of
					// the next transaction. If it tells us that the connection
					// should be closed, we can assume that the other side has
					// closed already and that we must re-open.
					int rep = 1;
					for (int i = ip.available(); i--> 0;)
						rep = ip.read();

					if (rep == 0) {
						// close and re-open.
						if (LOG.isEnabledFor(Priority.DEBUG)) {
							LOG.debug("Other party wanted the connection closed.");
						}
						try {
							outputStream.close();
							ip.close();
						} catch (Exception ignored) {}

						tcpSocket.close();
						continue;
					}
				}

				for( int eachBuffer = 0; eachBuffer < msgBuffers.size();eachBuffer++ ) {
					// Send the message
					outputStream.write( (byte[]) msgBuffers.elementAt(eachBuffer) );
				}

				outputStream.flush();
				setLastUsed(System.currentTimeMillis());
				success = true;
				break;

			} catch (Exception e) {
				// The connection has failed. Try to reconnects before failing.
				++retryAttempt;
				tcpSocket.close();
				if (LOG.isEnabledFor(Priority.DEBUG))
					LOG.debug("sendMessage current socket is closed.");
				continue;
			}
		}

		if (success) {
			// we force a resheduling here, allowing other threads to run
			++nbOfMessagesSent;
			Thread.yield();
		} else {
			tcpSocket.setLastFailed(System.currentTimeMillis());
			if (LOG.isEnabledFor(Priority.WARN))
				LOG.warn("sendMessage failed - exit");
			throw new IOException( "sendMessage failed - exit" );
		}
	}

	public void notifyActivity() {
		tcpSocket.notifyActivity();
	}

	private synchronized void notifyFailure() {
		close();
	}

	public synchronized void close() {

		tcpSocket.close();

		if (queue != null) {
			queue.close();
			queue = null;
		}
		if (thread != null) {
			try {
				thread.interrupt();
				thread = null;
			} catch (Exception ez1) {
				if (LOG.isEnabledFor(Priority.WARN))
					LOG.warn("Cannot interrupt thread for " + dstAddrString, ez1);
			}
		}
	}

	public synchronized  boolean isConnected() {
		Socket socket = tcpSocket.getSocket(1000);
		return socket != null;
	}

	public synchronized long getLastUsed () {
		return lastUsed;
	}

	public synchronized void setLastUsed (long time) {
		lastUsed = time;
	}

	// Just in case the code that allocated an instance of this object forgot to do "close".
	public void finalize() {
		close();
	}
}