DirUtil.java

/*
 * Copyright (c) 2010, Zepheira LLC, Some rights reserved.
 * 
 * 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 the openrdf.org 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
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 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 */
package org.openrdf.repository.object.managers.helpers;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;

/**
 * Singleton that will delete directory on normal JVM exit.
 * 
 * @author James Leigh
 * 
 */
public class DirUtil {
	static final Collection<File> temporary = new ArrayList<File>();

	public static File createTempDir(String prefix) throws IOException {
		String tmpDirStr = System.getProperty("java.io.tmpdir");
		if (tmpDirStr == null) {
			tmpDirStr = "tmp";
		}
		File tmpDir = new File(tmpDirStr);
		if (!tmpDir.exists()) {
			tmpDir.mkdirs();
		}
		File dir = File.createTempFile(prefix, "", tmpDir);
		dir.delete();
		dir.mkdirs();
		return dir;
	}

	public static void deleteOnExit(File dir) {
		synchronized (temporary) {
			if (temporary.isEmpty()) {
				Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {
					public void run() {
						synchronized (temporary) {
							for (File dir : temporary) {
								deleteFileOrDir(dir, 256);
							}
						}
					}
				}, "Temporary Directory Cleanup"));
			}
			temporary.add(dir);
		}
	}

	static void deleteFileOrDir(File dir, int max) {
		File[] listFiles = dir.listFiles();
		if (listFiles != null && max > 0) {
			for (File file : listFiles) {
				deleteFileOrDir(file, max - 1);
			}
		}
		dir.delete();
	}
}