filecontentimpl.java

jxta-cms-src-2.4.zip 是官网上的比较稳定的CMS源代码。目前是最稳定的高版本。

/*
 * Copyright (c) 2001 Sun Microsystems, Inc.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *       Sun Microsystems, Inc. for Project JXTA."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written
 *    permission, please contact Project JXTA at http://www.jxta.org.
 *
 * 5. Products derived from this software may not be called "JXTA",
 *    nor may "JXTA" appear in their name, without prior written
 *    permission of Sun.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of Project JXTA.  For more
 * information on Project JXTA, please see
 * <http://www.jxta.org/>.
 *
 * This license is based on the BSD license adopted by the Apache Foundation.
 *
 * $Id: FileContentImpl.java,v 1.6 2005/05/12 16:20:10 hamada Exp $
 *
 */

package net.jxta.share;

import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.IOException;
import net.jxta.share.metadata.ContentMetadata;

/*
 * FileContent implementation for shared content.
 */
class FileContentImpl implements FileContent {
    private File file;        // content file name
    private long mtime;               // last modified time
    private ContentAdvertisement adv; // content advertisement

    /*
     * Creates a new FileContent object for the specified file, content
     * name, content type, and description. If content name is null
     * then it defaults to the base name of the actual file path.
     * @param file the content file
     * @param name the content name, or null if file name to be used
     * @param type the mime type of the content, or null if not specified
     * @param desc the description of the content, or null if not specified
     * @exception FileNotFoundException if the file was not found
     * @exception IOException if there was an I/O error
     */
    FileContentImpl(File file, String name, String type, String desc)
    throws IOException {
        // normalize path name
        this.file = file = new File(file.getAbsolutePath());
        InputStream is = new FileInputStream(file);
        mtime = file.lastModified();
        long length = file.length();
        ContentId id = new ContentIdImpl(is);
        is.close();
        if (name == null) {
            name = file.getName();
        }
        adv = new ContentAdvertisementImpl(name, id, length, type, desc);
    }

    /*
     * Creates a new FileContent object for the specified file, content
     * name, content type, and metadata. If content name is null
     * then it defaults to the base name of the actual file path.
     * @param file the content file
     * @param name the content name, or null if file name to be used
     * @param type the mime type of the content, or null if not specified
     * @param metadata an array of ContentMetadata objects describing the
     *  content, or null if not specified
     * @exception FileNotFoundException if the file was not found
     * @exception IOException if there was an I/O error
     */
    FileContentImpl(File file, String name, String type
                    ,ContentMetadata[] metadata) throws IOException {
        // normalize path name
        this.file = file = new File(file.getAbsolutePath());
        InputStream is = new FileInputStream(file);
        mtime = file.lastModified();
        long length = file.length();
        ContentId id = new ContentIdImpl(is);
        is.close();
        if (name == null) {
            name = file.getName();
        }
        adv = new ContentAdvertisementImpl(name, id, length, type, metadata, null);
    }

    /**
     * Returns the File object associated with this content.
     */
    public File getFile() {
        return file;
    }

    /**
     * Returns the ContentAdvertisement.
     */

    public ContentAdvertisement getContentAdvertisement() {
        return adv;
    }

    /**
     * Returns an input stream for reading the content.
     * @exception IOException if there was an I/O error
     */
    public InputStream getInputStream() throws IOException {
        InputStream is = new FileInputStream(file);
        /* XXX may be not the right place
        if (mtime != file.lastModified()) {
            throw new IOException("File has been changed: " + file);
    }
        */
        return is;
    }

    /**
     * Returns a string representation of this FileContent object.
     */
    public String toString() {
        return "{file=" + file + ";mtime=" + mtime + ";adv=" + adv + "}";
    }
}