documentnode.java

Office格式转换代码

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2003 The Apache Software Foundation.  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
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache POI" must not be used to endorse or promote products
 *    derived from this software without prior written permission. For
 *    written permission, please contact [e-mail].
 *
 * 5. Products derived from this software may not be called "Apache",
 *    "Apache POI", nor may "Apache" appear in their name, without
 *    prior written permission of the Apache Software Foundation.
 *
 * 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 the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package org.apache.poi.poifs.filesystem;

import java.util.*;

import org.apache.poi.poifs.dev.POIFSViewable;
import org.apache.poi.poifs.property.DocumentProperty;

/**
 * Simple implementation of DocumentEntry
 *
 * @author Marc Johnson (mjohnson at apache dot org)
 */

public class DocumentNode
    extends EntryNode
    implements DocumentEntry, POIFSViewable
{

    // underlying POIFSDocument instance
    private POIFSDocument _document;

    /**
     * create a DocumentNode. This method is not public by design; it
     * is intended strictly for the internal use of this package
     *
     * @param property the DocumentProperty for this DocumentEntry
     * @param parent the parent of this entry
     */

    DocumentNode(final DocumentProperty property, final DirectoryNode parent)
    {
        super(property, parent);
        _document = property.getDocument();
    }

    /**
     * get the POIFSDocument
     *
     * @return the internal POIFSDocument
     */

    POIFSDocument getDocument()
    {
        return _document;
    }

    /* ********** START implementation of DocumentEntry ********** */

    /**
     * get the zize of the document, in bytes
     *
     * @return size in bytes
     */

    public int getSize()
    {
        return getProperty().getSize();
    }

    /* **********  END  implementation of DocumentEntry ********** */
    /* ********** START implementation of Entry ********** */

    /**
     * is this a DocumentEntry?
     *
     * @return true if the Entry is a DocumentEntry, else false
     */

    public boolean isDocumentEntry()
    {
        return true;
    }

    /* **********  END  implementation of Entry ********** */
    /* ********** START extension of Entry ********** */

    /**
     * extensions use this method to verify internal rules regarding
     * deletion of the underlying store.
     *
     * @return true if it's ok to delete the underlying store, else
     *         false
     */

    protected boolean isDeleteOK()
    {
        return true;
    }

    /* **********  END  extension of Entry ********** */
    /* ********** START begin implementation of POIFSViewable ********** */

    /**
     * Get an array of objects, some of which may implement
     * POIFSViewable
     *
     * @return an array of Object; may not be null, but may be empty
     */

    public Object [] getViewableArray()
    {
        return new Object[ 0 ];
    }

    /**
     * Get an Iterator of objects, some of which may implement
     * POIFSViewable
     *
     * @return an Iterator; may not be null, but may have an empty
     * back end store
     */

    public Iterator getViewableIterator()
    {
        List components = new ArrayList();

        components.add(getProperty());
        components.add(_document);
        return components.iterator();
    }

    /**
     * Give viewers a hint as to whether to call getViewableArray or
     * getViewableIterator
     *
     * @return true if a viewer should call getViewableArray, false if
     *         a viewer should call getViewableIterator
     */

    public boolean preferArray()
    {
        return false;
    }

    /**
     * Provides a short description of the object, to be used when a
     * POIFSViewable object has not provided its contents.
     *
     * @return short description
     */

    public String getShortDescription()
    {
        return getName();
    }

    /* **********  END  begin implementation of POIFSViewable ********** */
}   // end public class DocumentNode