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The basic runtime tools and interfaces for intarsys components.
There is a newer version: 4.11
/*
 * Copyright (c) 2007, intarsys consulting GmbH
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * - Redistributions of source code must retain the above copyright notice,
 *   this list of conditions and the following disclaimer.
 *
 * - 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.
 *
 * - Neither the name of intarsys 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 de.intarsys.tools.component;

import java.util.Set;

/**
 * A common implementation of IStartStop. This abstract class
 * ensures that start and stop procedures are executed only once.
 * 
 */
public abstract class CommonStartStop implements IStartStop {

	private boolean started = false;

	public CommonStartStop() {
		super();
	}

	/**
	 * Start the component lifecycle. This method is called once at most.
	 * 
	 */
	protected void basicStart() {
		// redefine
	}

	/**
	 * Stop the component lifecycle. This method is called once at most.
	 * 
	 */
	protected void basicStop() {
		// redefine
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see de.intarsys.tools.component.IStartStop#isStarted()
	 */
	synchronized public final boolean isStarted() {
		return started;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see de.intarsys.tools.component.IStartStop#start()
	 */
	public final void start() {
		synchronized (this) {
			if (started) {
				return;
			}
			basicStart();
			started = true;
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see de.intarsys.tools.component.IStartStop#stop()
	 */
	public final void stop() {
		synchronized (this) {
			if (!started) {
				return;
			}
			basicStop();
			started = false;
		}
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see de.intarsys.tools.component.IStartStop#stopRequested()
	 */
	public boolean stopRequested(Set visited) {
		return true;
	}

}