org.apache.poi.poifs.property.PropertyTable Maven / Gradle / Ivy
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this work for additional information regarding copyright ownership.
The ASF licenses this file to You under the Apache License, Version 2.0
(the "License"); you may not use this file except in compliance with
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http://www.apache.org/licenses/LICENSE-2.0
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package org.apache.poi.poifs.property;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.List;
import java.util.Stack;
import org.apache.poi.poifs.common.POIFSBigBlockSize;
import org.apache.poi.poifs.common.POIFSConstants;
import org.apache.poi.poifs.filesystem.BATManaged;
import org.apache.poi.poifs.storage.BlockWritable;
import org.apache.poi.poifs.storage.PropertyBlock;
import org.apache.poi.poifs.storage.RawDataBlockList;
/**
* This class embodies the Property Table for the filesystem; this is
* basically the dsirectory for all of the documents in the
* filesystem.
*
* @author Marc Johnson (mjohnson at apache dot org)
*/
public final class PropertyTable implements BATManaged, BlockWritable {
private POIFSBigBlockSize _bigBigBlockSize;
private int _start_block;
private List _properties;
private BlockWritable[] _blocks;
public PropertyTable(POIFSBigBlockSize bigBlockSize)
{
_bigBigBlockSize = bigBlockSize;
_start_block = POIFSConstants.END_OF_CHAIN;
_properties = new ArrayList();
addProperty(new RootProperty());
_blocks = null;
}
/**
* reading constructor (used when we've read in a file and we want
* to extract the property table from it). Populates the
* properties thoroughly
*
* @param startBlock the first block of the property table
* @param blockList the list of blocks
*
* @exception IOException if anything goes wrong (which should be
* a result of the input being NFG)
*/
public PropertyTable(final POIFSBigBlockSize bigBlockSize,
final int startBlock,
final RawDataBlockList blockList)
throws IOException
{
_bigBigBlockSize = bigBlockSize;
_start_block = POIFSConstants.END_OF_CHAIN;
_blocks = null;
_properties =
PropertyFactory
.convertToProperties(blockList.fetchBlocks(startBlock, -1));
populatePropertyTree(( DirectoryProperty ) _properties.get(0));
}
/**
* Add a property to the list of properties we manage
*
* @param property the new Property to manage
*/
public void addProperty(Property property)
{
_properties.add(property);
}
/**
* Remove a property from the list of properties we manage
*
* @param property the Property to be removed
*/
public void removeProperty(final Property property)
{
_properties.remove(property);
}
/**
* Get the root property
*
* @return the root property
*/
public RootProperty getRoot()
{
// it's always the first element in the List
return ( RootProperty ) _properties.get(0);
}
/**
* Prepare to be written
*/
public void preWrite()
{
Property[] properties = _properties.toArray(new Property[ 0 ]);
// give each property its index
for (int k = 0; k < properties.length; k++)
{
properties[ k ].setIndex(k);
}
// allocate the blocks for the property table
_blocks = PropertyBlock.createPropertyBlockArray(_bigBigBlockSize, _properties);
// prepare each property for writing
for (int k = 0; k < properties.length; k++)
{
properties[ k ].preWrite();
}
}
/**
* Get the start block for the property table
*
* @return start block index
*/
public int getStartBlock()
{
return _start_block;
}
private void populatePropertyTree(DirectoryProperty root)
throws IOException
{
int index = root.getChildIndex();
if (!Property.isValidIndex(index))
{
// property has no children
return;
}
Stack children = new Stack();
children.push(_properties.get(index));
while (!children.empty())
{
Property property = children.pop();
root.addChild(property);
if (property.isDirectory())
{
populatePropertyTree(( DirectoryProperty ) property);
}
index = property.getPreviousChildIndex();
if (Property.isValidIndex(index))
{
children.push(_properties.get(index));
}
index = property.getNextChildIndex();
if (Property.isValidIndex(index))
{
children.push(_properties.get(index));
}
}
}
/**
* Return the number of BigBlock's this instance uses
*
* @return count of BigBlock instances
*/
public int countBlocks()
{
return (_blocks == null) ? 0
: _blocks.length;
}
/**
* Set the start block for this instance
*
* @param index index into the array of BigBlock instances making
* up the the filesystem
*/
public void setStartBlock(final int index)
{
_start_block = index;
}
/**
* Write the storage to an OutputStream
*
* @param stream the OutputStream to which the stored data should
* be written
*
* @exception IOException on problems writing to the specified
* stream
*/
public void writeBlocks(final OutputStream stream)
throws IOException
{
if (_blocks != null)
{
for (int j = 0; j < _blocks.length; j++)
{
_blocks[ j ].writeBlocks(stream);
}
}
}
}