org.apache.commons.fileupload.disk.DiskFileItemFactory Maven / Gradle / Ivy
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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.commons.fileupload.disk;
import java.io.File;
import org.apache.commons.fileupload.FileItem;
import org.apache.commons.fileupload.FileItemFactory;
import org.apache.commons.io.FileCleaningTracker;
/**
* The default {@link org.apache.commons.fileupload.FileItemFactory}
* implementation. This implementation creates
* {@link org.apache.commons.fileupload.FileItem} instances which keep their
* content either in memory, for smaller items, or in a temporary file on disk,
* for larger items. The size threshold, above which content will be stored on
* disk, is configurable, as is the directory in which temporary files will be
* created.
*
* If not otherwise configured, the default configuration values are as
* follows:
*
* - Size threshold is 10KB.
* - Repository is the system default temp directory, as returned by
*
System.getProperty("java.io.tmpdir").
*
*
* NOTE: Files are created in the system default temp directory with
* predictable names. This means that a local attacker with write access to that
* directory can perform a TOUTOC attack to replace any uploaded file with a
* file of the attackers choice. The implications of this will depend on how the
* uploaded file is used but could be significant. When using this
* implementation in an environment with local, untrusted users,
* {@link #setRepository(File)} MUST be used to configure a repository location
* that is not publicly writable. In a Servlet container the location identified
* by the ServletContext attribute javax.servlet.context.tempdir
* may be used.
*
*
* Temporary files, which are created for file items, should be
* deleted later on. The best way to do this is using a
* {@link FileCleaningTracker}, which you can set on the
* {@link DiskFileItemFactory}. However, if you do use such a tracker,
* then you must consider the following: Temporary files are automatically
* deleted as soon as they are no longer needed. (More precisely, when the
* corresponding instance of {@link java.io.File} is garbage collected.)
* This is done by the so-called reaper thread, which is started and stopped
* automatically by the {@link FileCleaningTracker} when there are files to be
* tracked.
* It might make sense to terminate that thread, for example, if
* your web application ends. See the section on "Resource cleanup"
* in the users guide of commons-fileupload.
*
* @since FileUpload 1.1
*/
public class DiskFileItemFactory implements FileItemFactory {
// ----------------------------------------------------- Manifest constants
/**
* The default threshold above which uploads will be stored on disk.
*/
public static final int DEFAULT_SIZE_THRESHOLD = 10240;
// ----------------------------------------------------- Instance Variables
/**
* The directory in which uploaded files will be stored, if stored on disk.
*/
private File repository;
/**
* The threshold above which uploads will be stored on disk.
*/
private int sizeThreshold = DEFAULT_SIZE_THRESHOLD;
/**
* The instance of {@link FileCleaningTracker}, which is responsible
* for deleting temporary files.
* May be null, if tracking files is not required.
*/
private FileCleaningTracker fileCleaningTracker;
/**
* Default content charset to be used when no explicit charset
* parameter is provided by the sender.
*/
private String defaultCharset = DiskFileItem.DEFAULT_CHARSET;
// ----------------------------------------------------------- Constructors
/**
* Constructs an unconfigured instance of this class. The resulting factory
* may be configured by calling the appropriate setter methods.
*/
public DiskFileItemFactory() {
this(DEFAULT_SIZE_THRESHOLD, null);
}
/**
* Constructs a preconfigured instance of this class.
*
* @param sizeThreshold The threshold, in bytes, below which items will be
* retained in memory and above which they will be
* stored as a file.
* @param repository The data repository, which is the directory in
* which files will be created, should the item size
* exceed the threshold.
*/
public DiskFileItemFactory(int sizeThreshold, File repository) {
this.sizeThreshold = sizeThreshold;
this.repository = repository;
}
// ------------------------------------------------------------- Properties
/**
* Returns the directory used to temporarily store files that are larger
* than the configured size threshold.
*
* @return The directory in which temporary files will be located.
*
* @see #setRepository(java.io.File)
*
*/
public File getRepository() {
return repository;
}
/**
* Sets the directory used to temporarily store files that are larger
* than the configured size threshold.
*
* @param repository The directory in which temporary files will be located.
*
* @see #getRepository()
*
*/
public void setRepository(File repository) {
this.repository = repository;
}
/**
* Returns the size threshold beyond which files are written directly to
* disk. The default value is 10240 bytes.
*
* @return The size threshold, in bytes.
*
* @see #setSizeThreshold(int)
*/
public int getSizeThreshold() {
return sizeThreshold;
}
/**
* Sets the size threshold beyond which files are written directly to disk.
*
* @param sizeThreshold The size threshold, in bytes.
*
* @see #getSizeThreshold()
*
*/
public void setSizeThreshold(int sizeThreshold) {
this.sizeThreshold = sizeThreshold;
}
// --------------------------------------------------------- Public Methods
/**
* Create a new {@link org.apache.commons.fileupload.disk.DiskFileItem}
* instance from the supplied parameters and the local factory
* configuration.
*
* @param fieldName The name of the form field.
* @param contentType The content type of the form field.
* @param isFormField true if this is a plain form field;
* false otherwise.
* @param fileName The name of the uploaded file, if any, as supplied
* by the browser or other client.
*
* @return The newly created file item.
*/
@Override
public FileItem createItem(String fieldName, String contentType,
boolean isFormField, String fileName) {
DiskFileItem result = new DiskFileItem(fieldName, contentType,
isFormField, fileName, sizeThreshold, repository);
result.setDefaultCharset(defaultCharset);
FileCleaningTracker tracker = getFileCleaningTracker();
if (tracker != null) {
tracker.track(result.getTempFile(), result);
}
return result;
}
/**
* Returns the tracker, which is responsible for deleting temporary
* files.
*
* @return An instance of {@link FileCleaningTracker}, or null
* (default), if temporary files aren't tracked.
*/
public FileCleaningTracker getFileCleaningTracker() {
return fileCleaningTracker;
}
/**
* Sets the tracker, which is responsible for deleting temporary
* files.
*
* @param pTracker An instance of {@link FileCleaningTracker},
* which will from now on track the created files, or null
* (default), to disable tracking.
*/
public void setFileCleaningTracker(FileCleaningTracker pTracker) {
fileCleaningTracker = pTracker;
}
/**
* Returns the default charset for use when no explicit charset
* parameter is provided by the sender.
* @return the default charset
*/
public String getDefaultCharset() {
return defaultCharset;
}
/**
* Sets the default charset for use when no explicit charset
* parameter is provided by the sender.
* @param pCharset the default charset
*/
public void setDefaultCharset(String pCharset) {
defaultCharset = pCharset;
}
}