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/*
* 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.tika.io;
import java.io.Closeable;
import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.LinkedList;
import org.apache.tika.exception.TikaException;
import java.util.logging.Level;
import java.util.logging.Logger;
/**
* Utility class for tracking and ultimately closing or otherwise disposing
* a collection of temporary resources.
*
* Note that this class is not thread-safe.
*
* @since Apache Tika 0.10
*/
public class TemporaryResources implements Closeable {
private static final Logger LOG = Logger.getLogger(TemporaryResources.class.getName());
/**
* Tracked resources in LIFO order.
*/
private final LinkedList resources = new LinkedList<>();
/**
* Directory for temporary files, null for the system default.
*/
private Path tempFileDir = null;
/**
* Sets the directory to be used for the temporary files created by
* the {@link #createTempFile()} method.
*
* @param tempFileDir temporary file directory,
* or null for the system default
*/
public void setTemporaryFileDirectory(Path tempFileDir) {
this.tempFileDir = tempFileDir;
}
/**
* Sets the directory to be used for the temporary files created by
* the {@link #createTempFile()} method.
*
* @param tempFileDir temporary file directory,
* or null for the system default
* @see #setTemporaryFileDirectory(Path)
*/
public void setTemporaryFileDirectory(File tempFileDir) {
this.tempFileDir = tempFileDir == null ? null : tempFileDir.toPath();
}
/**
* Creates a temporary file that will automatically be deleted when
* the {@link #close()} method is called, returning its path.
*
* @return Path to created temporary file that will be deleted after closing
* @throws IOException
*/
public Path createTempFile() throws IOException {
final Path path = tempFileDir == null
? Files.createTempFile("apache-tika-", ".tmp")
: Files.createTempFile(tempFileDir, "apache-tika-", ".tmp");
addResource(new Closeable() {
public void close() throws IOException {
try {
Files.delete(path);
} catch (IOException e) {
// delete when exit if current delete fail
LOG.log(Level.WARNING, "delete tmp file failed; will delete it on exit");
path.toFile().deleteOnExit();
}
}
});
return path;
}
/**
* Creates and returns a temporary file that will automatically be
* deleted when the {@link #close()} method is called.
*
* @return Created temporary file that'll be deleted after closing
* @throws IOException
* @see #createTempFile()
*/
public File createTemporaryFile() throws IOException {
return createTempFile().toFile();
}
/**
* Adds a new resource to the set of tracked resources that will all be
* closed when the {@link #close()} method is called.
*
* @param resource resource to be tracked
*/
public void addResource(Closeable resource) {
resources.addFirst(resource);
}
/**
* Returns the latest of the tracked resources that implements or
* extends the given interface or class.
*
* @param klass interface or class
* @return matching resource, or null if not found
*/
@SuppressWarnings("unchecked")
public T getResource(Class klass) {
for (Closeable resource : resources) {
if (klass.isAssignableFrom(resource.getClass())) {
return (T) resource;
}
}
return null;
}
/**
* Closes all tracked resources. The resources are closed in reverse order
* from how they were added.
*
* Any suppressed exceptions from managed resources are collected and
* then added to the first thrown exception, which is re-thrown once
* all the resources have been closed.
*
* @throws IOException if one or more of the tracked resources
* could not be closed
*/
public void close() throws IOException {
// Release all resources and keep track of any exceptions
IOException exception = null;
for (Closeable resource : resources) {
try {
resource.close();
} catch (IOException e) {
if (exception == null) {
exception = e;
} else {
exception.addSuppressed(e);
}
}
}
resources.clear();
// Throw any exceptions that were captured from above
if (exception != null) {
throw exception;
}
}
/**
* Calls the {@link #close()} method and wraps the potential
* {@link IOException} into a {@link TikaException} for convenience
* when used within Tika.
*
* @throws TikaException if one or more of the tracked resources
* could not be closed
*/
public void dispose() throws TikaException {
try {
close();
} catch (IOException e) {
throw new TikaException("Failed to close temporary resources", e);
}
}
}