org.apache.harmony.luni.util.DeleteOnExit Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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
*
* 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.
*/
package org.apache.harmony.luni.util;
import java.io.File;
import java.util.ArrayList;
import java.util.Collections;
/**
* Implements the actual DeleteOnExit mechanism. Is registered as a shutdown
* hook in the Runtime, once it is actually being used.
*/
public class DeleteOnExit extends Thread {
/**
* Our singleton instance.
*/
private static DeleteOnExit instance;
/**
* Our list of files scheduled for deletion.
*/
private ArrayList files = new ArrayList();
/**
* Returns our singleton instance, creating it if necessary.
*/
public static synchronized DeleteOnExit getInstance() {
if (instance == null) {
instance = new DeleteOnExit();
Runtime.getRuntime().addShutdownHook(instance);
}
return instance;
}
/**
* Schedules a file for deletion.
*
* @param filename The file to delete.
*/
public void addFile(String filename) {
synchronized(files) {
if (!files.contains(filename)) {
files.add(filename);
}
}
}
/**
* Does the actual work. Note we (a) first sort the files lexicographically
* and then (b) delete them in reverse order. This is to make sure files
* get deleted before their parent directories.
*/
@Override
public void run() {
Collections.sort(files);
for (int i = files.size() - 1; i >= 0; i--) {
new File(files.get(i)).delete();
}
}
}