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
020 package org.crsh.util;
021
022 import java.io.Closeable;
023 import java.util.ArrayList;
024 import java.util.concurrent.atomic.AtomicBoolean;
025 import java.util.logging.Level;
026 import java.util.logging.Logger;
027
028 public 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 Safe.close(closeable);
072 }
073 }
074 }
075 }