rrdfilebackendfactory.java

来自「jrobin,使用纯java实现的RRD数据库,使用RRD数据库来统计数据.」· Java 代码 · 共 72 行

/* ============================================================
 * JRobin : Pure java implementation of RRDTool's functionality
 * ============================================================
 *
 * Project Info:  http://www.jrobin.org
 * Project Lead:  Sasa Markovic ([e-mail]);
 *
 * (C) Copyright 2003-2005, by Sasa Markovic.
 *
 * Developers:    Sasa Markovic ([e-mail])
 *
 *
 * This library is free software; you can redistribute it and/or modify it under the terms
 * of the GNU Lesser General Public License as published by the Free Software Foundation;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 */

package org.jrobin.core;

import java.io.IOException;

/**
 * Factory class which creates actual {@link RrdFileBackend} objects. This was the default
 * backend factory in JRobin before 1.4.0 release.
 */
public class RrdFileBackendFactory extends RrdBackendFactory {
	/**
	 * factory name, "FILE"
	 */
	public static final String NAME = "FILE";

	/**
	 * Creates RrdFileBackend object for the given file path.
	 *
	 * @param path	 File path
	 * @param readOnly True, if the file should be accessed in read/only mode.
	 *                 False otherwise.
	 * @return RrdFileBackend object which handles all I/O operations for the given file path
	 * @throws IOException Thrown in case of I/O error.
	 */
	protected RrdBackend open(String path, boolean readOnly) throws IOException {
		return new RrdFileBackend(path, readOnly);
	}

	/**
	 * Method to determine if a file with the given path already exists.
	 *
	 * @param path File path
	 * @return True, if such file exists, false otherwise.
	 */
	protected boolean exists(String path) {
		return Util.fileExists(path);
	}

	/**
	 * Returns the name of this factory.
	 *
	 * @return Factory name (equals to string "FILE")
	 */
	public String getFactoryName() {
		return NAME;
	}
}