echopoint.tucana.event.DefaultUploadCallback.java Source code

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Here is the source code for echopoint.tucana.event.DefaultUploadCallback.java

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/*
 * This file is part of the Echo Point Project.  This project is a
 * collection of Components that have extended the Echo Web Application
 * Framework Version 3.
 *
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (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.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 */
package echopoint.tucana.event;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;

import static java.lang.String.format;
import org.apache.commons.io.IOUtils;

/**
 * A default implementation of an {@link UploadCallback} that saves the
 * uploaded file(s) to a specified directory.
 *
 * <p><b>Note:</b> Development of this component was sponsored by <a
 * href='http://tcnbroadcasting.com/index.jsp' target='_top'>TCN
 * Broadcasting</a>.  We are grateful for their support and sponsorship.</p>
 *
 * @author Rakesh 2008-11-9
 * @version $Id$
 */
public class DefaultUploadCallback extends UploadCallbackAdapter {
    private static final long serialVersionUID = 1L;

    /** The file separator character to use. */
    protected static final String FILE_SEPARATOR = System.getProperty("file.separator");

    /** The system default temporary directory. */
    protected static final String TEMP_DIR = System.getProperty("java.io.tmpdir");

    /** The directory to which uploaded files are to be saved. */
    private File directory;

    /** Default constructor to allow sub-classing. */
    protected DefaultUploadCallback() {
    }

    /**
     * Create a new callback handler that saves files to the specified directory.
     *
     * @param directory The directory to which files are to be saved.
     * @throws IllegalArgumentException If the file specified is not a directory.
     */
    public DefaultUploadCallback(final File directory) throws IllegalArgumentException {
        setDirectory(directory);
    }

    /**
     * Over-ridden to save the contents of the uploaded file to {@link #directory}.
     * Client-code should ideally wrap this method in a try-catch clause to
     * handle file copying errors and update the UI as appropriate.
     *
     * {@inheritDoc}
     * @throws RuntimeException If errors are encountered while copying the
     *   uploaded file to the specified directory.
     */
    @Override
    public void uploadSucceeded(final UploadFinishEvent event) {
        final File temp = getTempFile();
        final File file = getFileName(event.getFileName());

        try {
            event.getFileItem().write(temp);

            if (!temp.renameTo(file)) {
                final BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(file));
                final BufferedInputStream bis = new BufferedInputStream(new FileInputStream(temp));
                IOUtils.copy(bis, bos);
                bis.close();
                bos.close();
                temp.delete();
                logger.log(level,
                        "Rename of temp file to " + file.getAbsolutePath() + " failed.  Recopied from source.");
            }

            event.getFileItem().delete();

            logger.log(level, "Copied upload file contents to: " + file.getAbsolutePath());
        } catch (Exception e) {
            throw new RuntimeException("Error copying uploaded file!", e);
        }

        super.uploadSucceeded(event);
    }

    /**
     * Return a file object that represents the uploaded file that is to be
     * saved.
     *
     * @param name The file name of the uploaded file.
     * @return The new file object that represents the file to be saved.
     */
    protected File getFileName(final String name) {
        return new File(directory.getAbsolutePath() + FILE_SEPARATOR + name);
    }

    /**
     * Return a temporary file to which the contents of the uploaded file will
     * be initially written.  This file will then be moved to the proper
     * destination file.  This ensures atomic creation of the new file.
     *
     * @return The temporary file to create.
     */
    protected File getTempFile() {
        return new File(directory.getAbsolutePath() + FILE_SEPARATOR + "echopoint.tempfile."
                + System.currentTimeMillis() + ".tmp");
    }

    /**
     * Accessor for property 'directory'.
     *
     * @return Value for property 'directory'.
     */
    public File getDirectory() {
        return directory;
    }

    /**
     * Mutator for property 'directory'.
     *
     * @param directory Value to set for property 'directory'.
     * @throws IllegalArgumentException If the file specified is not a directory.
     */
    public void setDirectory(final File directory) throws IllegalArgumentException {
        if (!directory.exists()) {
            if (!directory.mkdirs()) {
                throw new IllegalArgumentException(format("Unable to create directory! {%s}", directory));
            }
        }

        if (!directory.isDirectory()) {
            throw new IllegalArgumentException(format("File specified must be a directory! {%s}", directory));
        }

        this.directory = directory;
    }
}