src/org/sonews/daemon/AbstractDaemon.java
author František Kučera <franta-hg@frantovo.cz>
Thu, 05 Jul 2012 13:19:19 +0200
changeset 119 f5b57e221e38
parent 37 74139325d305
permissions -rwxr-xr-x
mezery, tabulátory
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/*
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 *   SONEWS News Server
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 *   see AUTHORS for the list of contributors
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 *
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 *   This program is free software: you can redistribute it and/or modify
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 *   it under the terms of the GNU General Public License as published by
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 *   the Free Software Foundation, either version 3 of the License, or
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 *   (at your option) any later version.
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 *
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 *   This program is distributed in the hope that it will be useful,
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 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
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 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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 *   GNU General Public License for more details.
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 *
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 *   You should have received a copy of the GNU General Public License
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 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
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 */
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package org.sonews.daemon;
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import java.sql.SQLException;
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import org.sonews.storage.StorageManager;
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import org.sonews.util.Log;
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/**
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 * Base class of all sonews threads.
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 * Instances of this class will be automatically registered at the ShutdownHook
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 * to be cleanly exited when the server is forced to exit.
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 * @author Christian Lins
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 * @since sonews/0.5.0
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 */
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public abstract class AbstractDaemon extends Thread
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{
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	/** This variable is write synchronized through setRunning */
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	private boolean isRunning = false;
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	/**
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	 * Protected constructor. Will be called by derived classes.
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	 */
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	protected AbstractDaemon()
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	{
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		setDaemon(true); // VM will exit when all threads are daemons
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		setName(getClass().getSimpleName());
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	}
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	/**
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	 * @return true if shutdown() was not yet called.
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	 */
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	public boolean isRunning()
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	{
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		synchronized (this) {
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			return this.isRunning;
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		}
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	}
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	/**
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	 * Marks this thread to exit soon. Closes the associated JDBCDatabase connection
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	 * if available.
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	 * @throws java.sql.SQLException
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	 */
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	public void shutdownNow()
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		throws SQLException
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	{
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		synchronized (this) {
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			this.isRunning = false;
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			StorageManager.disableProvider();
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		}
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	}
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	/**
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	 * Calls shutdownNow() but catches SQLExceptions if occurring.
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	 */
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	public void shutdown()
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	{
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		try {
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			shutdownNow();
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		} catch (SQLException ex) {
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			Log.get().warning(ex.toString());
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		}
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	}
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	/**
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	 * Starts this daemon.
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	 */
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	@Override
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	public void start()
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	{
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		synchronized (this) {
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			this.isRunning = true;
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		}
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		super.start();
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	}
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}