taverna-scufl2-ucfpackage/src/main/java/org/apache/taverna/scufl2/ucfpackage/impl/odfdom/pkg/TempDirDeleter.java

/************************************************************************
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
 *
 * Copyright 2008, 2010 Oracle and/or its affiliates. All rights reserved.
 *
 * Use is subject to license terms.
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy
 * of the License at http://www.apache.org/licenses/LICENSE-2.0. You can also
 * obtain a copy of the License at http://odftoolkit.org/docs/license.txt
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 ************************************************************************/
/*  This file is derived from ODFDOM 0.8.6, and
 *  has been modified for Apache Taverna.
 *  (c) 2010-2014 University of Manchester
 *  (c) 2015 The Apache Software Foundation
 */
package org.apache.taverna.scufl2.ucfpackage.impl.odfdom.pkg;

import java.io.File;
import java.util.ArrayList;
import java.util.Iterator;

class TempDirDeleter extends Thread {
    private static TempDirDeleter deleterThread = null;
    private ArrayList<File> dirList;

    static TempDirDeleter getInstance() {
        if (deleterThread == null) {
            deleterThread = new TempDirDeleter();
            Runtime.getRuntime().addShutdownHook(deleterThread);
        }
        return deleterThread;
    }

    private TempDirDeleter() {
        dirList = new ArrayList<>();
    }

    synchronized boolean add(File dir) {
        return dirList.add(dir);
    }

    synchronized boolean remove(File dir) {
        return dirList.remove(dir);
    }

    @Override
    public void run() {
        synchronized (this) {
            Iterator<File> iterator = dirList.iterator();
            while (iterator.hasNext()) {
                File dir = iterator.next();
                deleteDirectoryRecursive(dir);
                iterator.remove();
            }
            dirList.clear();
        }
    }

    private void deleteDirectoryRecursive(File dir) {
        if (dir == null)
            return;

        File[] fileArray = dir.listFiles();
        if (fileArray != null)
            for (int i = 0; i < fileArray.length; i++)
                if (fileArray[i].isDirectory())
                    deleteDirectoryRecursive(fileArray[i]);
                else
                    fileArray[i].delete();
        dir.delete();
    }

    void deleteDirectory(File dir) {
        deleteDirectoryRecursive(dir);
        dirList.remove(dir);
    }
}