org.springframework.http.codec.multipart.FileStorage Maven / Gradle / Ivy
/*
* Copyright 2002-2021 the original author or authors.
*
* 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
*
* https://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.springframework.http.codec.multipart;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.util.function.Supplier;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import reactor.core.publisher.Mono;
import reactor.core.scheduler.Scheduler;
/**
* Represents a directory used to store parts larger than
* {@link DefaultPartHttpMessageReader#setMaxInMemorySize(int)}.
*
* @author Arjen Poutsma
* @since 5.3.7
*/
abstract class FileStorage {
private static final Log logger = LogFactory.getLog(FileStorage.class);
protected FileStorage() {
}
/**
* Get the mono of the directory to store files in.
*/
public abstract Mono directory();
/**
* Create a new {@code FileStorage} from a user-specified path. Creates the
* path if it does not exist.
*/
public static FileStorage fromPath(Path path) throws IOException {
if (!Files.exists(path)) {
Files.createDirectory(path);
}
return new PathFileStorage(path);
}
/**
* Create a new {@code FileStorage} based on a temporary directory.
* @param scheduler the scheduler to use for blocking operations
*/
public static FileStorage tempDirectory(Supplier scheduler) {
return new TempFileStorage(scheduler);
}
private static final class PathFileStorage extends FileStorage {
private final Mono directory;
public PathFileStorage(Path directory) {
this.directory = Mono.just(directory);
}
@Override
public Mono directory() {
return this.directory;
}
}
private static final class TempFileStorage extends FileStorage {
private static final String IDENTIFIER = "spring-multipart-";
private final Supplier scheduler;
private volatile Mono directory = tempDirectory();
public TempFileStorage(Supplier scheduler) {
this.scheduler = scheduler;
}
@Override
public Mono directory() {
return this.directory
.flatMap(this::createNewDirectoryIfDeleted)
.subscribeOn(this.scheduler.get());
}
private Mono createNewDirectoryIfDeleted(Path directory) {
if (!Files.exists(directory)) {
// Some daemons remove temp directories. Let's create a new one.
Mono newDirectory = tempDirectory();
this.directory = newDirectory;
return newDirectory;
}
else {
return Mono.just(directory);
}
}
private static Mono tempDirectory() {
return Mono.fromCallable(() -> {
Path directory = Files.createTempDirectory(IDENTIFIER);
if (logger.isDebugEnabled()) {
logger.debug("Created temporary storage directory: " + directory);
}
return directory;
}).cache();
}
}
}