001/*
002 * Sonar, open source software quality management tool.
003 * Copyright (C) 2008-2012 SonarSource
004 * mailto:contact AT sonarsource DOT com
005 *
006 * Sonar is free software; you can redistribute it and/or
007 * modify it under the terms of the GNU Lesser General Public
008 * License as published by the Free Software Foundation; either
009 * version 3 of the License, or (at your option) any later version.
010 *
011 * Sonar is distributed in the hope that it will be useful,
012 * but WITHOUT ANY WARRANTY; without even the implied warranty of
013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014 * Lesser General Public License for more details.
015 *
016 * You should have received a copy of the GNU Lesser General Public
017 * License along with Sonar; if not, write to the Free Software
018 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02
019 */
020package org.sonar.api.utils;
021
022import java.io.File;
023import java.io.IOException;
024
025public final class TempFileUtils {
026
027  private TempFileUtils() {
028    // only static methods
029  }
030
031  /**
032   * Create a temporary directory. This directory is NOT deleted when the JVM stops, because using File#deleteOnExit()
033   * is evil (google "deleteonExit evil"). Copied from http://stackoverflow.com/questions/617414/create-a-temporary-directory-in-java :
034   * <ol>
035   * <li>deleteOnExit() only deletes for normal JVM shutdowns, not crashes or killing the JVM process</li>
036   * <li>deleteOnExit() only deletes on JVM shutdown - not good for long running server processes because 3 :</li>
037   * <li>The most evil of all - deleteOnExit() consumes memory for each temp file entry. If your process is running for months,
038   * or creates a lot of temp files in a short time, you consume memory and never release it until the JVM
039   * shuts down.</li>
040   * </ol>
041   */
042  public static File createTempDirectory() throws IOException {
043    return createTempDirectory("temp");
044  }
045
046  public static File createTempDirectory(String prefix) throws IOException {
047    final File temp = File.createTempFile(prefix, Long.toString(System.nanoTime()));
048    if (!temp.delete()) {
049      throw new IOException("Could not delete temp file: " + temp.getAbsolutePath());
050    }
051
052    if (!temp.mkdir()) {
053      throw new IOException("Could not create temp directory: " + temp.getAbsolutePath());
054    }
055    return temp;
056  }
057}