property.java

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/* ====================================================================
   Copyright 2002-2004   Apache Software Foundation

   Licensed 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.poi.poifs.property;

import java.io.*;

import java.util.*;

import org.apache.poi.hpsf.ClassID;

import org.apache.poi.poifs.common.POIFSConstants;
import org.apache.poi.poifs.dev.POIFSViewable;
import org.apache.poi.util.ByteField;
import org.apache.poi.util.IntegerField;
import org.apache.poi.util.LittleEndianConsts;
import org.apache.poi.util.ShortField;

/**
 * This abstract base class is the ancestor of all classes
 * implementing POIFS Property behavior.
 *
 * @author Marc Johnson (mjohnson at apache dot org)
 */

public abstract class Property
    implements Child, POIFSViewable
{
    static final private byte   _default_fill             = ( byte ) 0x00;
    static final private int    _name_size_offset         = 0x40;
    static final private int    _max_name_length          =
        (_name_size_offset / LittleEndianConsts.SHORT_SIZE) - 1;
    static final protected int  _NO_INDEX                 = -1;

    // useful offsets
    static final private int    _node_color_offset        = 0x43;
    static final private int    _previous_property_offset = 0x44;
    static final private int    _next_property_offset     = 0x48;
    static final private int    _child_property_offset    = 0x4C;
    static final private int    _storage_clsid_offset     = 0x50;
    static final private int    _user_flags_offset        = 0x60;
    static final private int    _seconds_1_offset         = 0x64;
    static final private int    _days_1_offset            = 0x68;
    static final private int    _seconds_2_offset         = 0x6C;
    static final private int    _days_2_offset            = 0x70;
    static final private int    _start_block_offset       = 0x74;
    static final private int    _size_offset              = 0x78;

    // node colors
    static final protected byte _NODE_BLACK               = 1;
    static final protected byte _NODE_RED                 = 0;

    // documents must be at least this size to be stored in big blocks
    static final private int    _big_block_minimum_bytes  = 4096;
    private String              _name;
    private ShortField          _name_size;
    private ByteField           _property_type;
    private ByteField           _node_color;
    private IntegerField        _previous_property;
    private IntegerField        _next_property;
    private IntegerField        _child_property;
    private ClassID             _storage_clsid;
    private IntegerField        _user_flags;
    private IntegerField        _seconds_1;
    private IntegerField        _days_1;
    private IntegerField        _seconds_2;
    private IntegerField        _days_2;
    private IntegerField        _start_block;
    private IntegerField        _size;
    private byte[]              _raw_data;
    private int                 _index;
    private Child               _next_child;
    private Child               _previous_child;

    /**
     * Default constructor
     */

    protected Property()
    {
        _raw_data = new byte[ POIFSConstants.PROPERTY_SIZE ];
        Arrays.fill(_raw_data, _default_fill);
        _name_size         = new ShortField(_name_size_offset);
        _property_type     =
            new ByteField(PropertyConstants.PROPERTY_TYPE_OFFSET);
        _node_color        = new ByteField(_node_color_offset);
        _previous_property = new IntegerField(_previous_property_offset,
                                              _NO_INDEX, _raw_data);
        _next_property     = new IntegerField(_next_property_offset,
                                              _NO_INDEX, _raw_data);
        _child_property    = new IntegerField(_child_property_offset,
                                              _NO_INDEX, _raw_data);
        _storage_clsid     = new ClassID(_raw_data,_storage_clsid_offset);
        _user_flags        = new IntegerField(_user_flags_offset, 0, _raw_data);
        _seconds_1         = new IntegerField(_seconds_1_offset, 0,
                                              _raw_data);
        _days_1            = new IntegerField(_days_1_offset, 0, _raw_data);
        _seconds_2         = new IntegerField(_seconds_2_offset, 0,
                                              _raw_data);
        _days_2            = new IntegerField(_days_2_offset, 0, _raw_data);
        _start_block       = new IntegerField(_start_block_offset);
        _size              = new IntegerField(_size_offset, 0, _raw_data);
        _index             = _NO_INDEX;
        setName("");
        setNextChild(null);
        setPreviousChild(null);
    }

    /**
     * Constructor from byte data
     *
     * @param index index number
     * @param array byte data
     * @param offset offset into byte data
     */

    protected Property(final int index, final byte [] array, final int offset)
    {
        _raw_data = new byte[ POIFSConstants.PROPERTY_SIZE ];
        System.arraycopy(array, offset, _raw_data, 0,
                         POIFSConstants.PROPERTY_SIZE);
        _name_size         = new ShortField(_name_size_offset, _raw_data);
        _property_type     =
            new ByteField(PropertyConstants.PROPERTY_TYPE_OFFSET, _raw_data);
        _node_color        = new ByteField(_node_color_offset, _raw_data);
        _previous_property = new IntegerField(_previous_property_offset,
                                              _raw_data);
        _next_property     = new IntegerField(_next_property_offset,
                                              _raw_data);
        _child_property    = new IntegerField(_child_property_offset,
                                              _raw_data);
        _storage_clsid     = new ClassID(_raw_data,_storage_clsid_offset);
        _user_flags        = new IntegerField(_user_flags_offset, 0, _raw_data);
        _seconds_1         = new IntegerField(_seconds_1_offset, _raw_data);
        _days_1            = new IntegerField(_days_1_offset, _raw_data);
        _seconds_2         = new IntegerField(_seconds_2_offset, _raw_data);
        _days_2            = new IntegerField(_days_2_offset, _raw_data);
        _start_block       = new IntegerField(_start_block_offset, _raw_data);
        _size              = new IntegerField(_size_offset, _raw_data);
        _index             = index;
        int name_length = (_name_size.get() / LittleEndianConsts.SHORT_SIZE)
                          - 1;

        if (name_length < 1)
        {
            _name = "";
        }
        else
        {
            char[] char_array  = new char[ name_length ];
            int    name_offset = 0;

            for (int j = 0; j < name_length; j++)
            {
                char_array[ j ] = ( char ) new ShortField(name_offset,
                                                          _raw_data).get();
                name_offset     += LittleEndianConsts.SHORT_SIZE;
            }
            _name = new String(char_array, 0, name_length);
        }
        _next_child     = null;
        _previous_child = null;
    }

    /**
     * Write the raw data to an OutputStream.
     *
     * @param stream the OutputStream to which the data should be
     *               written.
     *
     * @exception IOException on problems writing to the specified
     *            stream.
     */

    public void writeData(final OutputStream stream)
        throws IOException
    {
        stream.write(_raw_data);
    }

    /**
     * Set the start block for the document referred to by this
     * Property.
     *
     * @param startBlock the start block index
     */

    public void setStartBlock(final int startBlock)
    {
        _start_block.set(startBlock, _raw_data);
    }

    /**
     * @return the start block
     */

    public int getStartBlock()
    {
        return _start_block.get();
    }

    /**
     * find out the document size
     *
     * @return size in bytes
     */

    public int getSize()
    {
        return _size.get();
    }

    /**
     * Based on the currently defined size, should this property use
     * small blocks?
     *
     * @return true if the size is less than _big_block_minimum_bytes
     */

    public boolean shouldUseSmallBlocks()
    {
        return Property.isSmall(_size.get());
    }

    /**
     * does the length indicate a small document?
     *
     * @param length length in bytes
     *
     * @return true if the length is less than
     *         _big_block_minimum_bytes
     */

    public static boolean isSmall(final int length)
    {
        return length < _big_block_minimum_bytes;
    }

    /**
     * Get the name of this property
     *
     * @return property name as String
     */

    public String getName()
    {
        return _name;
    }

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

    abstract public boolean isDirectory();

    /**
     * Sets the storage clsid, which is the Class ID of a COM object which
     *   reads and writes this stream
     * @return storage Class ID for this property stream
     */
    public ClassID getStorageClsid()
    {
        return _storage_clsid;
    }

    /**
     * Set the name; silently truncates the name if it's too long.
     *
     * @param name the new name
     */
    protected final void setName(final String name)
    {