VDRConnection.java

/*
 * Copyright (c) Henrik Niehaus & Lazy Bones development team
 * 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. Neither the name of the project (Lazy Bones) nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS 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 THE COPYRIGHT OWNER OR 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.
 */
package lazybones;

import java.io.IOException;
import java.util.TimerTask;

import lazybones.actions.responses.ConnectionProblem;
import lazybones.logging.LoggingConstants;

import org.hampelratte.svdrp.Command;
import org.hampelratte.svdrp.Connection;
import org.hampelratte.svdrp.Response;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author <a href="hampelratte@users.sf.net">hampelratte@users.sf.net </a>
 *
 */
public class VDRConnection {

    private static transient Logger logger = LoggerFactory.getLogger(LoggingConstants.CONNECTION_LOGGER);

    private static Connection connection;

    public static String host;

    public static int port;

    public static int timeout = 500;

    public static String charset;

    /**
     * If set, the connection will be kept open for some time, so that consecutive request will be much faster
     */
    public static boolean persistentConnection;

    private static java.util.Timer timer;

    private static long lastTransmissionTime = 0;

    /**
     * The time in ms, the connection will be kept alive after the last request. {@link #persistentConnection} has to be set to true.
     */
    private static final int CONNECTION_KEEP_ALIVE = 15000;

    /**
     * Sends a SVDRP command to VDR and returns a response object, which represents the vdr response
     *
     * @param cmd
     *            The SVDRP command to send
     * @return The SVDRP response or null, if the Command couldn't be sent
     */
    public synchronized static Response send(final Command cmd) {
        Response res = null;
        try {
            if (connection == null) {
                logger.debug("New connection to {}:{} with charset {}", new Object[] { host, port, charset });
                connection = new Connection(VDRConnection.host, VDRConnection.port, VDRConnection.timeout, charset);
            } else {
                logger.trace("old connection");
            }

            res = connection.send(cmd);
            lastTransmissionTime = System.currentTimeMillis();
            if (!persistentConnection) {
                connection.close();
                connection = null;
            } else {
                if (timer == null) {
                    logger.debug("Starting connection closer");
                    timer = new java.util.Timer("SVDRP connection closer");
                    timer.schedule(new ConnectionCloser(), 0, 100);
                }
            }
        } catch (Exception e1) {
            connection = null; // set connection to null, so that the next request will establish a new one
            res = new ConnectionProblem();
            logger.error(res.getMessage(), e1);
        }

        return res;
    }

    static class ConnectionCloser extends TimerTask {
        @Override
        public void run() {
            if (connection != null && (System.currentTimeMillis() - lastTransmissionTime) > CONNECTION_KEEP_ALIVE) {
                logger.debug("Closing connection");
                try {
                    timer.cancel();
                    timer = null;
                    connection.close();
                    connection = null;
                } catch (IOException e) {
                    logger.error("Couldn't close connection", e);
                }
            }
        }
    }

    /*
     * private class ConnectionTester implements Runnable {
     *
     * private int timeout; private ProgressMonitor pm; private boolean running = true;
     *
     * ConnectionTester(int timeout, ProgressMonitor pm) { this.timeout = timeout; this.pm = pm; }
     *
     * public boolean isRunning() { return running; }
     *
     * public void run() { running = true; for (int i = 0; i < timeout; i++) { pm.setProgress(i); pm.setNote( (timeout-i) + " Seconds übrig"); if
     * (pm.isCanceled()) { break; }
     *
     * try { Connection connection = new Connection(VDRConnection.host, VDRConnection.port, VDRConnection.timeout); Connection.DEBUG = true; Response resp =
     * connection.send(new STAT()); if (resp != null) { LOG.log("WOL-Process finished", Logger.CONNECTION, Logger.DEBUG); pm.close(); break; }
     * connection.close(); } catch (Exception e) { }
     *
     * try { Thread.sleep(1000); } catch (InterruptedException e) { e.printStackTrace(); } } pm.close(); running = false; } }
     */
}