| /* |
| * Copyright (c) 2005, Oracle and/or its affiliates. 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. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package com.sun.imageio.stream; |
| |
| import java.io.IOException; |
| import javax.imageio.stream.ImageInputStream; |
| |
| /** |
| * Small class to assist in properly closing an ImageInputStream instance |
| * prior to garbage collection. The ImageInputStreamImpl class defines a |
| * finalize() method, but in a number of its public subclasses |
| * (e.g. FileImageInputStream) we override the finalize() method to be |
| * empty for performance reasons, and instead rely on the Disposer mechanism |
| * for closing/disposing resources. This is fine when one of these classes |
| * is instantiated directly (e.g. new FileImageInputStream()) but in the |
| * unlikely case where a user defines their own subclass of one of those |
| * streams, we need some way to get back to the behavior of |
| * ImageInputStreamImpl, which will call close() as part of finalization. |
| * |
| * Typically an Image{Input,Output}Stream will construct an instance of |
| * StreamFinalizer in its constructor if it detects that it has been |
| * subclassed by the user. The ImageInputStream instance will hold a |
| * reference to the StreamFinalizer, and the StreamFinalizer will hold a |
| * reference back to the ImageInputStream from which it was created. When |
| * both are no longer reachable, the StreamFinalizer.finalize() method will |
| * be called, which will take care of closing down the ImageInputStream. |
| * |
| * Clearly this is a bit of a hack, but it will likely only be used in the |
| * rarest of circumstances: when a user has subclassed one of the public |
| * stream classes. (It should be no worse than the old days when the public |
| * stream classes had non-empty finalize() methods.) |
| */ |
| public class StreamFinalizer { |
| private ImageInputStream stream; |
| |
| public StreamFinalizer(ImageInputStream stream) { |
| this.stream = stream; |
| } |
| |
| protected void finalize() throws Throwable { |
| try { |
| stream.close(); |
| } catch (IOException e) { |
| } finally { |
| stream = null; |
| super.finalize(); |
| } |
| } |
| } |