httpclientconnection.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: HttpClientConnection.java,v 1.7 2002/06/19 01:17:36 jice 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.servlethttp;

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

import java.io.*;
import java.net.*;

import org.apache.log4j.Category;
import org.apache.log4j.Priority;

/**
 * Simple messenger that simply posts a message to a URL.
 * URL/HttpURLConnection is used, so (depending on your JDK) you will get
 * reasonably good persistent connection management.
 */
 
public class HttpClientConnection implements EndpointMessenger, Runnable {

    /** standard log object **/
    private static final Category LOG =
	Category.getInstance(HttpClientConnection.class.getName());

    public static final int MaxNbOfMessages = 40;

    private URL url = null;

    private boolean waiting = false;
    private long lastUsed = 0;
    private Thread thread = null;
    private EndpointReceiveQueue queue = null; // Type is missnomer. We use
                                               // as a send Queue here.
    private long nbOfMessagesSent = 0;
    private static final MimeMediaType msgType = new MimeMediaType( "application/x-jxta-msg" );

    /** constructs the messenger.
     *  @param url The URL of where we're going to send the message. This
     *      may be the final destination, or it may be an intermediary.
     *  @param localAddress the local peer's address. this is the source
     *      address for the message.
     *  @param destAddress the destination peer address. This is the dest
     *      address for the message.
     */
    public HttpClientConnection (URL url) {

	this.url = url;
    }


    private synchronized void setThreadName () {

	if (thread != null) {
	    try {
		thread.setName ("HTTP Connection to " + url.toString() + " [" +
				queue.getNbOfQueuedMessages() + ", " +
				nbOfMessagesSent + " ]");
	    } catch (Exception ez1) {
		if (LOG.isEnabledFor(Priority.ERROR)) LOG.error("Cannot change thread name", ez1);
	    }
	}
    }

    /**
     * Send the message.
     */

    private void doSendMessage (Message msg) throws IOException {

	// send the message
	HttpURLConnection urlConn =
	    (HttpURLConnection) url.openConnection();

	urlConn.setDoOutput(true);
	urlConn.setRequestMethod("POST");
	urlConn.connect();
	BufferedOutputStream out = new BufferedOutputStream(urlConn.getOutputStream());

	out.flush();		// flush out http headers

	MessageWireFormatFactory.newMessageWireFormat(msgType).writeMessage(out, msg);

	out.flush();
	out.close();
	int code = urlConn.getResponseCode();

	if (code!=HttpUtil.HTTP_SC_OK) {
	    throw new IOException ("Message not accepted: HTTP status " +
				   "code=" + code + " reason=" +
				   urlConn.getResponseMessage() );
	} else {
	    ++nbOfMessagesSent;
	}
	setThreadName();
    }

    /*
     * Buffered version
    */
    public void sendMessage (Message msg) throws IOException {

    	connect();

	synchronized (this) {
	    queue.push (msg);
	}
	setThreadName();
	Thread.yield();
    }

    /*
     * unbuffered version.
    public void sendMessage (Message msg) throws IOException {

	try {
	    // Wait for messages to be sent.
	    doSendMessage (msg);
	} catch (IOException ez2) {
	    // The message failed. Notify the failure
	    notifyFailure();
	}
    }
    */

    // 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();
		setThreadName();

		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;
	    }
	}
    }


    // 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, "HTTP Connection to " + url.toString() + " [Unused]");
	    thread.start();
	}
	Thread.yield();
    }

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

    public synchronized void 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 " + url.toString(), ez1);
	    }
	}
    }

    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();
    }

}