/* ObjectPlusFilesInputStream** $Id: ObjectPlusFilesInputStream.java,v 1.3 2005/11/04 00:00:46 stack-sf Exp $** Created on Apr 28, 2004** Copyright (C) 2004 Internet Archive.** This file is part of the Heritrix web crawler (crawler.archive.org).** Heritrix is free software; you can redistribute it and/or modify* it under the terms of the GNU Lesser Public License as published by* the Free Software Foundation; either version 2.1 of the License, or* any later version.** Heritrix 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 Lesser Public License for more details.** You should have received a copy of the GNU Lesser Public License* along with Heritrix; if not, write to the Free Software* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA*/package org.archive.io;import java.io.File;import java.io.IOException;import java.io.InputStream;import java.io.ObjectInputStream;import java.util.Iterator;import java.util.LinkedList;import org.archive.util.FileUtils;/** * Enhanced ObjectOutputStream with support for restoring * files that had been saved, in parallel with object * serialization. * * @author gojomo * */public class ObjectPlusFilesInputStream extends ObjectInputStream {    LinkedList auxiliaryDirectoryStack = new LinkedList();    LinkedList postRestoreTasks = new LinkedList();    /**     * Instantiate over the given stream and using the supplied     * auxiliary storage directory.     *     * @param in     * @param storeDir     * @throws IOException     */    public ObjectPlusFilesInputStream(InputStream in, File storeDir)    throws IOException {        super(in);        auxiliaryDirectoryStack.addFirst(storeDir);    }    /**     * Push another default storage directory for use     * until popped.     *     * @param dir     */    public void pushAuxiliaryDirectory(String dir) {        auxiliaryDirectoryStack.            addFirst(new File(getAuxiliaryDirectory(), dir));    }    /**     * Discard the top auxiliary directory.     */    public void popAuxiliaryDirectory() {        auxiliaryDirectoryStack.removeFirst();    }    /**     * Return the top auxiliary directory, from     * which saved files are restored.     *     * @return Auxillary directory.     */    public File getAuxiliaryDirectory() {        return (File)auxiliaryDirectoryStack.getFirst();    }    /**     * Restore a file from storage, using the name and length     * info on the serialization stream and the file from the     * current auxiliary directory, to the given File.     *     * @param destination     * @throws IOException     */    public void restoreFile(File destination) throws IOException {        String nameAsStored = readUTF();        long lengthAtStoreTime = readLong();        File storedFile = new File(getAuxiliaryDirectory(),nameAsStored);        FileUtils.copyFile(storedFile, destination, lengthAtStoreTime);    }    /**     * Restore a file from storage, using the name and length     * info on the serialization stream and the file from the     * current auxiliary directory, to the given File.     *     * @param directory     * @throws IOException     */    public void restoreFileTo(File directory) throws IOException {        String nameAsStored = readUTF();        long lengthAtStoreTime = readLong();        File storedFile = new File(getAuxiliaryDirectory(),nameAsStored);        File destination = new File(directory,nameAsStored);        FileUtils.copyFile(storedFile, destination, lengthAtStoreTime);    }    /**     * Register a task to be done when the ObjectPlusFilesInputStream     * is closed.     *     * @param task     */    public void registerFinishTask(Runnable task) {        postRestoreTasks.addFirst(task);    }    private void doFinishTasks() {    	Iterator iter = postRestoreTasks.iterator();    	while(iter.hasNext()) {    		((Runnable)iter.next()).run();        }    }    /**     * In addition to default, do any registered cleanup tasks.     *     * @see java.io.InputStream#close()     */    public void close() throws IOException {        super.close();        doFinishTasks();    }}