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Apache POI - Java API To Access Microsoft Format Files
/* ====================================================================
Licensed to the Apache Software Foundation (ASF) under one or more
contributor license agreements. See the NOTICE file distributed with
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
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.filesystem;
import java.io.ByteArrayInputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import org.apache.poi.poifs.common.POIFSBigBlockSize;
import org.apache.poi.poifs.common.POIFSConstants;
import org.apache.poi.poifs.dev.POIFSViewable;
import org.apache.poi.poifs.property.DirectoryProperty;
import org.apache.poi.poifs.property.Property;
import org.apache.poi.poifs.property.PropertyTable;
import org.apache.poi.poifs.storage.BATBlock;
import org.apache.poi.poifs.storage.BlockAllocationTableReader;
import org.apache.poi.poifs.storage.BlockAllocationTableWriter;
import org.apache.poi.poifs.storage.BlockList;
import org.apache.poi.poifs.storage.BlockWritable;
import org.apache.poi.poifs.storage.HeaderBlock;
import org.apache.poi.poifs.storage.HeaderBlockConstants;
import org.apache.poi.poifs.storage.HeaderBlockWriter;
import org.apache.poi.poifs.storage.RawDataBlockList;
import org.apache.poi.poifs.storage.SmallBlockTableReader;
import org.apache.poi.poifs.storage.SmallBlockTableWriter;
import org.apache.poi.util.CloseIgnoringInputStream;
import org.apache.poi.util.IOUtils;
import org.apache.poi.util.LongField;
import org.apache.poi.util.POILogFactory;
import org.apache.poi.util.POILogger;
/**
* This is the main class of the POIFS system; it manages the entire
* life cycle of the filesystem.
* This is the older version, which uses more memory, and doesn't
* support in-place writes.
*/
public class OPOIFSFileSystem
implements POIFSViewable
{
private static final POILogger _logger =
POILogFactory.getLogger(OPOIFSFileSystem.class);
/**
* Convenience method for clients that want to avoid the auto-close behaviour of the constructor.
*/
public static InputStream createNonClosingInputStream(InputStream is) {
return new CloseIgnoringInputStream(is);
}
private PropertyTable _property_table;
private List _documents;
private DirectoryNode _root;
/**
* What big block size the file uses. Most files
* use 512 bytes, but a few use 4096
*/
private POIFSBigBlockSize bigBlockSize =
POIFSConstants.SMALLER_BIG_BLOCK_SIZE_DETAILS;
/**
* Constructor, intended for writing
*/
public OPOIFSFileSystem()
{
HeaderBlock header_block = new HeaderBlock(bigBlockSize);
_property_table = new PropertyTable(header_block);
_documents = new ArrayList();
_root = null;
}
/**
* Create a OPOIFSFileSystem from an InputStream. Normally the stream is read until
* EOF. The stream is always closed.
*
* Some streams are usable after reaching EOF (typically those that return true
* for markSupported()). In the unlikely case that the caller has such a stream
* and needs to use it after this constructor completes, a work around is to wrap the
* stream in order to trap the close() call. A convenience method (
* createNonClosingInputStream()) has been provided for this purpose:
*
* InputStream wrappedStream = OPOIFSFileSystem.createNonClosingInputStream(is);
* HSSFWorkbook wb = new HSSFWorkbook(wrappedStream);
* is.reset();
* doSomethingElse(is);
*
* Note also the special case of ByteArrayInputStream for which the close()
* method does nothing.
*
* ByteArrayInputStream bais = ...
* HSSFWorkbook wb = new HSSFWorkbook(bais); // calls bais.close() !
* bais.reset(); // no problem
* doSomethingElse(bais);
*
*
* @param stream the InputStream from which to read the data
*
* @exception IOException on errors reading, or on invalid data
*/
public OPOIFSFileSystem(InputStream stream)
throws IOException
{
this();
boolean success = false;
HeaderBlock header_block;
RawDataBlockList data_blocks;
try {
// read the header block from the stream
header_block = new HeaderBlock(stream);
bigBlockSize = header_block.getBigBlockSize();
// read the rest of the stream into blocks
data_blocks = new RawDataBlockList(stream, bigBlockSize);
success = true;
} finally {
closeInputStream(stream, success);
}
// set up the block allocation table (necessary for the
// data_blocks to be manageable
new BlockAllocationTableReader(header_block.getBigBlockSize(),
header_block.getBATCount(),
header_block.getBATArray(),
header_block.getXBATCount(),
header_block.getXBATIndex(),
data_blocks);
// get property table from the document
PropertyTable properties =
new PropertyTable(header_block, data_blocks);
// init documents
processProperties(
SmallBlockTableReader.getSmallDocumentBlocks(
bigBlockSize, data_blocks, properties.getRoot(),
header_block.getSBATStart()
),
data_blocks,
properties.getRoot().getChildren(),
null,
header_block.getPropertyStart()
);
// For whatever reason CLSID of root is always 0.
getRoot().setStorageClsid(properties.getRoot().getStorageClsid());
}
/**
* @param stream the stream to be closed
* @param success false
if an exception is currently being thrown in the calling method
*/
protected void closeInputStream(InputStream stream, boolean success) {
if(stream.markSupported() && !(stream instanceof ByteArrayInputStream)) {
String msg = "POIFS is closing the supplied input stream of type ("
+ stream.getClass().getName() + ") which supports mark/reset. "
+ "This will be a problem for the caller if the stream will still be used. "
+ "If that is the case the caller should wrap the input stream to avoid this close logic. "
+ "This warning is only temporary and will not be present in future versions of POI.";
_logger.log(POILogger.WARN, msg);
}
try {
stream.close();
} catch (IOException e) {
if(success) {
throw new RuntimeException(e);
}
// else not success? Try block did not complete normally
// just print stack trace and leave original ex to be thrown
_logger.log(POILogger.ERROR, "can't close input stream", e);
}
}
/**
* Checks that the supplied InputStream (which MUST
* support mark and reset, or be a PushbackInputStream)
* has a POIFS (OLE2) header at the start of it.
* If your InputStream does not support mark / reset,
* then wrap it in a PushBackInputStream, then be
* sure to always use that, and not the original!
* @param inp An InputStream which supports either mark/reset, or is a PushbackInputStream
*/
public static boolean hasPOIFSHeader(InputStream inp) throws IOException {
// We want to peek at the first 8 bytes
byte[] header = IOUtils.peekFirst8Bytes(inp);
return hasPOIFSHeader(header);
}
/**
* Checks if the supplied first 8 bytes of a stream / file
* has a POIFS (OLE2) header.
*/
public static boolean hasPOIFSHeader(byte[] header8Bytes) {
LongField signature = new LongField(HeaderBlockConstants._signature_offset, header8Bytes);
// Did it match the signature?
return (signature.get() == HeaderBlockConstants._signature);
}
/**
* Create a new document to be added to the root directory
*
* @param stream the InputStream from which the document's data
* will be obtained
* @param name the name of the new POIFSDocument
*
* @return the new DocumentEntry
*
* @exception IOException on error creating the new POIFSDocument
*/
public DocumentEntry createDocument(final InputStream stream,
final String name)
throws IOException
{
return getRoot().createDocument(name, stream);
}
/**
* create a new DocumentEntry in the root entry; the data will be
* provided later
*
* @param name the name of the new DocumentEntry
* @param size the size of the new DocumentEntry
* @param writer the writer of the new DocumentEntry
*
* @return the new DocumentEntry
*
* @exception IOException
*/
public DocumentEntry createDocument(final String name, final int size,
final POIFSWriterListener writer)
throws IOException
{
return getRoot().createDocument(name, size, writer);
}
/**
* create a new DirectoryEntry in the root directory
*
* @param name the name of the new DirectoryEntry
*
* @return the new DirectoryEntry
*
* @exception IOException on name duplication
*/
public DirectoryEntry createDirectory(final String name)
throws IOException
{
return getRoot().createDirectory(name);
}
/**
* Write the filesystem out
*
* @param stream the OutputStream to which the filesystem will be
* written
*
* @exception IOException thrown on errors writing to the stream
*/
public void writeFilesystem(final OutputStream stream)
throws IOException
{
// get the property table ready
_property_table.preWrite();
// create the small block store, and the SBAT
SmallBlockTableWriter sbtw =
new SmallBlockTableWriter(bigBlockSize, _documents, _property_table.getRoot());
// create the block allocation table
BlockAllocationTableWriter bat =
new BlockAllocationTableWriter(bigBlockSize);
// create a list of BATManaged objects: the documents plus the
// property table and the small block table
List