org.apache.poi.hpsf.MutablePropertySet 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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package org.apache.poi.hpsf;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.ListIterator;
import org.apache.poi.poifs.filesystem.DirectoryEntry;
import org.apache.poi.poifs.filesystem.Entry;
import org.apache.poi.util.LittleEndian;
import org.apache.poi.util.LittleEndianConsts;
/**
* Adds writing support to the {@link PropertySet} class.
*
* Please be aware that this class' functionality will be merged into the
* {@link PropertySet} class at a later time, so the API will change.
*
* @author Rainer Klute <[email protected]>
* @version $Id: MutablePropertySet.java 489730 2006-12-22 19:18:16Z bayard $
* @since 2003-02-19
*/
public class MutablePropertySet extends PropertySet
{
/**
* Constructs a MutablePropertySet instance. Its
* primary task is to initialize the immutable field with their proper
* values. It also sets fields that might change to reasonable defaults.
*/
public MutablePropertySet()
{
/* Initialize the "byteOrder" field. */
byteOrder = LittleEndian.getUShort(BYTE_ORDER_ASSERTION);
/* Initialize the "format" field. */
format = LittleEndian.getUShort(FORMAT_ASSERTION);
/* Initialize "osVersion" field as if the property has been created on
* a Win32 platform, whether this is the case or not. */
osVersion = (OS_WIN32 << 16) | 0x0A04;
/* Initailize the "classID" field. */
classID = new ClassID();
/* Initialize the sections. Since property set must have at least
* one section it is added right here. */
sections = new LinkedList();
sections.add(new MutableSection());
}
/**
* Constructs a MutablePropertySet by doing a deep copy of
* an existing PropertySet. All nested elements, i.e.
* Sections and Property instances, will be their
* mutable counterparts in the new MutablePropertySet.
*
* @param ps The property set to copy
*/
public MutablePropertySet(final PropertySet ps)
{
byteOrder = ps.getByteOrder();
format = ps.getFormat();
osVersion = ps.getOSVersion();
setClassID(ps.getClassID());
clearSections();
for (final Iterator i = ps.getSections().iterator(); i.hasNext();)
{
final MutableSection s = new MutableSection((Section) (i.next()));
addSection(s);
}
}
/**
* The length of the property set stream header.
*/
private final int OFFSET_HEADER =
BYTE_ORDER_ASSERTION.length + /* Byte order */
FORMAT_ASSERTION.length + /* Format */
LittleEndianConsts.INT_SIZE + /* OS version */
ClassID.LENGTH + /* Class ID */
LittleEndianConsts.INT_SIZE; /* Section count */
/**
* Sets the "byteOrder" property.
*
* @param byteOrder the byteOrder value to set
*/
public void setByteOrder(final int byteOrder)
{
this.byteOrder = byteOrder;
}
/**
* Sets the "format" property.
*
* @param format the format value to set
*/
public void setFormat(final int format)
{
this.format = format;
}
/**
* Sets the "osVersion" property.
*
* @param osVersion the osVersion value to set
*/
public void setOSVersion(final int osVersion)
{
this.osVersion = osVersion;
}
/**
* Sets the property set stream's low-level "class ID"
* field.
*
* @param classID The property set stream's low-level "class ID" field.
*
* @see PropertySet#getClassID()
*/
public void setClassID(final ClassID classID)
{
this.classID = classID;
}
/**
* Removes all sections from this property set.
*/
public void clearSections()
{
sections = null;
}
/**
* Adds a section to this property set.
*
* @param section The {@link Section} to add. It will be appended
* after any sections that are already present in the property set
* and thus become the last section.
*/
public void addSection(final Section section)
{
if (sections == null)
sections = new LinkedList();
sections.add(section);
}
/**
* Writes the property set to an output stream.
*
* @param out the output stream to write the section to
* @exception IOException if an error when writing to the output stream
* occurs
* @exception WritingNotSupportedException if HPSF does not yet support
* writing a property's variant type.
*/
public void write(final OutputStream out)
throws WritingNotSupportedException, IOException
{
/* Write the number of sections in this property set stream. */
final int nrSections = sections.size();
int length = 0;
/* Write the property set's header. */
length += TypeWriter.writeToStream(out, (short) getByteOrder());
length += TypeWriter.writeToStream(out, (short) getFormat());
length += TypeWriter.writeToStream(out, getOSVersion());
length += TypeWriter.writeToStream(out, getClassID());
length += TypeWriter.writeToStream(out, nrSections);
int offset = OFFSET_HEADER;
/* Write the section list, i.e. the references to the sections. Each
* entry in the section list consist of the section's class ID and the
* section's offset relative to the beginning of the stream. */
offset += nrSections * (ClassID.LENGTH + LittleEndian.INT_SIZE);
final int sectionsBegin = offset;
for (final ListIterator i = sections.listIterator(); i.hasNext();)
{
final MutableSection s = (MutableSection) i.next();
final ClassID formatID = s.getFormatID();
if (formatID == null)
throw new NoFormatIDException();
length += TypeWriter.writeToStream(out, s.getFormatID());
length += TypeWriter.writeUIntToStream(out, offset);
try
{
offset += s.getSize();
}
catch (HPSFRuntimeException ex)
{
final Throwable cause = ex.getReason();
if (cause instanceof UnsupportedEncodingException)
throw new IllegalPropertySetDataException(cause);
else
throw ex;
}
}
/* Write the sections themselves. */
offset = sectionsBegin;
for (final ListIterator i = sections.listIterator(); i.hasNext();)
{
final MutableSection s = (MutableSection) i.next();
offset += s.write(out);
}
}
/**
* Returns the contents of this property set stream as an input stream.
* The latter can be used for example to write the property set into a POIFS
* document. The input stream represents a snapshot of the property set.
* If the latter is modified while the input stream is still being
* read, the modifications will not be reflected in the input stream but in
* the {@link MutablePropertySet} only.
*
* @return the contents of this property set stream
*
* @throws WritingNotSupportedException if HPSF does not yet support writing
* of a property's variant type.
* @throws IOException if an I/O exception occurs.
*/
public InputStream toInputStream()
throws IOException, WritingNotSupportedException
{
final ByteArrayOutputStream psStream = new ByteArrayOutputStream();
write(psStream);
psStream.close();
final byte[] streamData = psStream.toByteArray();
return new ByteArrayInputStream(streamData);
}
/**
* Writes a property set to a document in a POI filesystem directory.
*
* @param dir The directory in the POI filesystem to write the document to.
* @param name The document's name. If there is already a document with the
* same name in the directory the latter will be overwritten.
*
* @throws WritingNotSupportedException
* @throws IOException
*/
public void write(final DirectoryEntry dir, final String name)
throws WritingNotSupportedException, IOException
{
/* If there is already an entry with the same name, remove it. */
try
{
final Entry e = dir.getEntry(name);
e.delete();
}
catch (FileNotFoundException ex)
{
/* Entry not found, no need to remove it. */
}
/* Create the new entry. */
dir.createDocument(name, toInputStream());
}
}