| /* |
| * Copyright 2005 Sun Microsystems, Inc. All Rights Reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Sun designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Sun in the LICENSE file that accompanied this code. |
| * |
| * This code 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 General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| * CA 95054 USA or visit www.sun.com if you need additional information or |
| * have any questions. |
| */ |
| |
| package com.sun.imageio.stream; |
| |
| import java.io.IOException; |
| import java.util.Set; |
| import java.util.WeakHashMap; |
| import javax.imageio.stream.ImageInputStream; |
| |
| /** |
| * This class provide means to properly close hanging |
| * image input/output streams on VM shutdown. |
| * This might be useful for proper cleanup such as removal |
| * of temporary files. |
| * |
| * Addition of stream do not prevent it from being garbage collected |
| * if no other references to it exists. Stream can be closed |
| * explicitly without removal from StreamCloser queue. |
| * Explicit removal from the queue only helps to save some memory. |
| */ |
| public class StreamCloser { |
| |
| private static WeakHashMap<ImageInputStream, Object> toCloseQueue; |
| private static Thread streamCloser; |
| |
| public static void addToQueue(ImageInputStream iis) { |
| synchronized (StreamCloser.class) { |
| if (toCloseQueue == null) { |
| toCloseQueue = |
| new WeakHashMap<ImageInputStream, Object>(); |
| } |
| |
| toCloseQueue.put(iis, null); |
| |
| if (streamCloser == null) { |
| final Runnable streamCloserRunnable = new Runnable() { |
| public void run() { |
| if (toCloseQueue != null) { |
| synchronized (StreamCloser.class) { |
| Set<ImageInputStream> set = |
| toCloseQueue.keySet(); |
| // Make a copy of the set in order to avoid |
| // concurrent modification (the is.close() |
| // will in turn call removeFromQueue()) |
| ImageInputStream[] streams = |
| new ImageInputStream[set.size()]; |
| streams = set.toArray(streams); |
| for (ImageInputStream is : streams) { |
| if (is != null) { |
| try { |
| is.close(); |
| } catch (IOException e) { |
| } |
| } |
| } |
| } |
| } |
| } |
| }; |
| |
| java.security.AccessController.doPrivileged( |
| new java.security.PrivilegedAction() { |
| public Object run() { |
| /* The thread must be a member of a thread group |
| * which will not get GCed before VM exit. |
| * Make its parent the top-level thread group. |
| */ |
| ThreadGroup tg = |
| Thread.currentThread().getThreadGroup(); |
| for (ThreadGroup tgn = tg; |
| tgn != null; |
| tg = tgn, tgn = tg.getParent()); |
| streamCloser = new Thread(tg, streamCloserRunnable); |
| Runtime.getRuntime().addShutdownHook(streamCloser); |
| return null; |
| } |
| }); |
| } |
| } |
| } |
| |
| public static void removeFromQueue(ImageInputStream iis) { |
| synchronized (StreamCloser.class) { |
| if (toCloseQueue != null) { |
| toCloseQueue.remove(iis); |
| } |
| } |
| } |
| } |