001/*
002 * Copyright (C) 2012 eXo Platform SAS.
003 *
004 * This is free software; you can redistribute it and/or modify it
005 * under the terms of the GNU Lesser General Public License as
006 * published by the Free Software Foundation; either version 2.1 of
007 * the License, or (at your option) any later version.
008 *
009 * This software is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * You should have received a copy of the GNU Lesser General Public
015 * License along with this software; if not, write to the Free
016 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018 */
019
020package org.crsh.util;
021
022import java.io.Closeable;
023import java.util.ArrayList;
024import java.util.concurrent.atomic.AtomicBoolean;
025import java.util.logging.Level;
026import java.util.logging.Logger;
027
028public final class CloseableList implements Closeable {
029
030  /** . */
031  final Logger log = Logger.getLogger(CloseableList.class.getName());
032
033  /** . */
034  private final ArrayList<Closeable> closeables;
035
036  /** . */
037  private final AtomicBoolean closed;
038
039  public CloseableList() {
040    this.closeables = new ArrayList<Closeable>();
041    this.closed = new AtomicBoolean(false);
042  }
043
044  public boolean isClosed() {
045    return closed.get();
046  }
047
048  /**
049   * Add a closeable to the list.
050   *
051   * @param closeable the closeable to add
052   * @throws IllegalStateException if the list is already closed
053   * @throws NullPointerException if the argument is null
054   */
055  public void add(Closeable closeable) throws IllegalStateException, NullPointerException {
056    if (closed.get()) {
057      throw new IllegalStateException("Already closed");
058    }
059    if (closeable == null) {
060      throw new NullPointerException("No null closeable accepted");
061    }
062    if (!closeables.contains(closeable)) {
063      closeables.add(closeable);
064    }
065  }
066
067  public void close() {
068    if (closed.compareAndSet(false, true)) {
069      for (Closeable closeable : closeables) {
070        log.log(Level.FINE, "Closing " + closeable.getClass().getSimpleName());
071        Utils.close(closeable);
072      }
073    }
074  }
075}