Commons FileUpload example source code file (DiskFileItemFactory.java)

This example Commons FileUpload source code file (DiskFileItemFactory.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Commons FileUpload tags/keywords

default_size_threshold, default_size_threshold, diskfileitem, diskfileitemfactory, diskfileitemfactory, file, file, filecleaningtracker, fileitem, fileitemfactory, io, string, string

The Commons FileUpload DiskFileItemFactory.java source code

/*
 * 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.FileCleaner;
import org.apache.commons.io.FileCleaningTracker;

/**
 * <p>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.</p>
 *
 * <p>If not otherwise configured, the default configuration values are as
 * follows:
 * <ul>
 *   <li>Size threshold is 10KB.
 *   <li>Repository is the system default temp directory, as returned by
 *       <code>System.getProperty("java.io.tmpdir").
 * </ul>
 * </p>
 *
 * <p>When using the DiskFileItemFactory, then you should
 * 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.)
 * Cleaning up those files is done by an instance of
 * {@link FileCleaningTracker}, and an associated thread. In a complex
 * environment, for example in a web application, you should consider
 * terminating this thread, for example, when your web application
 * ends. See the section on "Resource cleanup"
 * in the users guide of commons-fileupload.</p>
 *
 * @author <a href="mailto:martinc@apache.org">Martin Cooper
 *
 * @since FileUpload 1.1
 *
 * @version $Id: DiskFileItemFactory.java 544995 2007-06-06 23:51:28Z jochen $
 */
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;


    /**
     * <p>The instance of {@link FileCleaningTracker}, which is responsible
     * for deleting temporary files.</p>
     * <p>May be null, if tracking files is not required.

     */
    private FileCleaningTracker fileCleaningTracker;

    // ----------------------------------------------------------- Constructors


    /**
     * Constructs an unconfigured instance of this class. The resulting factory
     * may be configured by calling the appropriate setter methods.
     * @deprecated Use
     *     {@link #DiskFileItemFactory(FileCleaningTracker, int, File)}.
     */
    public DiskFileItemFactory() {
        this(FileCleaner.getInstance(), 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.
     * @deprecated Use
     *     {@link #DiskFileItemFactory(FileCleaningTracker, int, File)}.
     */
    public DiskFileItemFactory(int sizeThreshold, File repository) {
        this(FileCleaner.getInstance(), sizeThreshold, repository);
    }

    /**
     * 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.
     * @param tracker       The tracker, which is responsible to delete
     *                      temporary files. May be null, if files don't need
     *                      to be tracked.
     */
    public DiskFileItemFactory(FileCleaningTracker tracker, int sizeThreshold,
            File repository) {
        this.sizeThreshold = sizeThreshold;
        this.repository = repository;
        this.fileCleaningTracker = tracker;
    }

    // ------------------------------------------------------------- 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 <code>true if this is a plain form field;
     *                    <code>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.
     */
    public FileItem createItem(
            String fieldName,
            String contentType,
            boolean isFormField,
            String fileName
            ) {
        return new DiskFileItem(this, fieldName, contentType,
                isFormField, fileName);
    }

    /**
     * Returns the tracker, which is responsible for deleting temporary
     * files.
     * @return An instance of {@link FileCleaningTracker}, defaults to
     *   {@link FileCleaner#getInstance()}. Null, if temporary files
     *   aren't tracked.
     */
    public FileCleaningTracker getFileCleaningTracker() {
        return fileCleaningTracker;
    }

    /**
     * Returns 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. May be null
     *   to disable tracking.
     */
    public void setFileCleaningTracker(FileCleaningTracker pTracker) {
        fileCleaningTracker = pTracker;
    }

}