directoryproperty.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.property;

import java.util.*;

import java.io.IOException;

import org.apache.poi.poifs.storage.SmallDocumentBlock;

/**
 * Directory property
 *
 * @author Marc Johnson (mjohnson at apache dot org)
 */

public class DirectoryProperty
    extends Property
    implements Parent
{

    // List of Property instances
    private List _children;

    // set of children's names
    private Set  _children_names;

    /**
     * Default constructor
     *
     * @param name the name of the directory
     */

    public DirectoryProperty(String name)
    {
        super();
        _children       = new ArrayList();
        _children_names = new HashSet();
        setName(name);
        setSize(0);
        setPropertyType(PropertyConstants.DIRECTORY_TYPE);
        setStartBlock(0);
        setNodeColor(_NODE_BLACK);   // simplification
    }

    /**
     * reader constructor
     *
     * @param index index number
     * @param array byte data
     * @param offset offset into byte data
     */

    protected DirectoryProperty(final int index, final byte [] array,
                                final int offset)
    {
        super(index, array, offset);
        _children       = new ArrayList();
        _children_names = new HashSet();
    }

    /**
     * Change a Property's name
     *
     * @param property the Property whose name is being changed
     * @param newName the new name for the Property
     *
     * @return true if the name change could be made, else false
     */

    public boolean changeName(final Property property, final String newName)
    {
        boolean result;
        String  oldName = property.getName();

        property.setName(newName);
        String cleanNewName = property.getName();

        if (_children_names.contains(cleanNewName))
        {

            // revert the change
            property.setName(oldName);
            result = false;
        }
        else
        {
            _children_names.add(cleanNewName);
            _children_names.remove(oldName);
            result = true;
        }
        return result;
    }

    /**
     * Delete a Property
     *
     * @param property the Property being deleted
     *
     * @return true if the Property could be deleted, else false
     */

    public boolean deleteChild(final Property property)
    {
        boolean result = _children.remove(property);

        if (result)
        {
            _children_names.remove(property.getName());
        }
        return result;
    }

    private class PropertyComparator
        implements Comparator
    {

        /**
         * Object equality, implemented as object identity
         *
         * @param o Object we're being compared to
         *
         * @return true if identical, else false
         */

        public boolean equals(Object o)
        {
            return this == o;
        }

        /**
         * compare method. Assumes both parameters are non-null
         * instances of Property. One property is less than another if
         * its name is shorter than the other property's name. If the
         * names are the same length, the property whose name comes
         * before the other property's name, alphabetically, is less
         * than the other property.
         *
         * @param o1 first object to compare, better be a Property
         * @param o2 second object to compare, better be a Property
         *
         * @return negative value if o1 <  o2,
         *         zero           if o1 == o2,
         *         positive value if o1 >  o2.
         */

        public int compare(Object o1, Object o2)
        {
            String name1  = (( Property ) o1).getName();
            String name2  = (( Property ) o2).getName();
            int    result = name1.length() - name2.length();

            if (result == 0)
            {
                result = name1.compareTo(name2);
            }
            return result;
        }
    }   // end private class PropertyComparator

    /* ********** START extension of Property ********** */

    /**
     * @return true if a directory type Property
     */

    public boolean isDirectory()
    {
        return true;
    }

    /**
     * Perform whatever activities need to be performed prior to
     * writing
     */

    protected void preWrite()
    {
        if (_children.size() > 0)
        {
            Property[] children =
                ( Property [] ) _children.toArray(new Property[ 0 ]);

            Arrays.sort(children, new PropertyComparator());
            int midpoint = children.length / 2;

            setChildProperty(children[ midpoint ].getIndex());
            children[ 0 ].setPreviousChild(null);
            children[ 0 ].setNextChild(null);
            for (int j = 1; j < midpoint; j++)
            {
                children[ j ].setPreviousChild(children[ j - 1 ]);
                children[ j ].setNextChild(null);
            }
            if (midpoint != 0)
            {
                children[ midpoint ]
                    .setPreviousChild(children[ midpoint - 1 ]);
            }
            if (midpoint != (children.length - 1))
            {
                children[ midpoint ].setNextChild(children[ midpoint + 1 ]);
                for (int j = midpoint + 1; j < children.length - 1; j++)
                {
                    children[ j ].setPreviousChild(null);
                    children[ j ].setNextChild(children[ j + 1 ]);
                }
                children[ children.length - 1 ].setPreviousChild(null);
                children[ children.length - 1 ].setNextChild(null);
            }
            else
            {
                children[ midpoint ].setNextChild(null);
            }
        }
    }

    /* **********  END  extension of Property ********** */
    /* ********** START implementation of Parent ********** */

    /**
     * Get an iterator over the children of this Parent; all elements
     * are instances of Property.
     *
     * @return Iterator of children; may refer to an empty collection
     */

    public Iterator getChildren()
    {
        return _children.iterator();
    }

    /**
     * Add a new child to the collection of children
     *
     * @param property the new child to be added; must not be null
     *
     * @exception IOException if we already have a child with the same
     *                        name
     */

    public void addChild(final Property property)
        throws IOException
    {
        String name = property.getName();

        if (_children_names.contains(name))
        {
            throw new IOException("Duplicate name \"" + name + "\"");
        }
        _children_names.add(name);
        _children.add(property);
    }

    /* **********  END  implementation of Parent ********** */
}   // end public class DirectoryProperty