PdfStream.java
/*
* $Id: PdfStream.java 4065 2009-09-16 23:09:11Z psoares33 $
*
* Copyright 1999, 2000, 2001, 2002 Bruno Lowagie
*
* The contents of this file are subject to the Mozilla Public License Version 1.1
* (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.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the License.
*
* The Original Code is 'iText, a free JAVA-PDF library'.
*
* The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
* the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
* All Rights Reserved.
* Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
* are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
*
* Contributor(s): all the names of the contributors are added in the source code
* where applicable.
*
* Alternatively, the contents of this file may be used under the terms of the
* LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
* provisions of LGPL are applicable instead of those above. If you wish to
* allow use of your version of this file only under the terms of the LGPL
* License and not to allow others to use your version of this file under
* the MPL, indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by the LGPL.
* If you do not delete the provisions above, a recipient may use your version
* of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the MPL as stated above or under the terms of the GNU
* Library General Public License as published by the Free Software Foundation;
* either version 2 of the License, or any later version.
*
* This library is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more
* details.
*
* If you didn't download this code from the following link, you should check if
* you aren't using an obsolete version:
* https://github.com/LibrePDF/OpenPDF
*/
package org.openpdf.text.pdf;
import org.openpdf.text.DocWriter;
import org.openpdf.text.Document;
import org.openpdf.text.ExceptionConverter;
import org.openpdf.text.error_messages.MessageLocalization;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.zip.Deflater;
import java.util.zip.DeflaterOutputStream;
/**
* <CODE>PdfStream</CODE> is the Pdf stream object.
* <p>
* A stream, like a string, is a sequence of characters. However, an application can read a small portion of a stream at
* a time, while a string must be read in its entirety. For this reason, objects with potentially large amounts of data,
* such as images and page descriptions, are represented as streams.<BR> A stream consists of a dictionary that
* describes a sequence of characters, followed by the keyword <B>stream</B>, followed by zero or more lines of
* characters, followed by the keyword <B>endstream</B>.<BR> All streams must be <CODE>PdfIndirectObject</CODE>s. The
* stream dictionary must be a direct object. The keyword <B>stream</B> that follows the stream dictionary should be
* followed by a carriage return and linefeed or just a linefeed.<BR> Remark: In this version only the
* FLATEDECODE-filter is supported.<BR> This object is described in the 'Portable Document Format Reference Manual
* version 1.7' section 3.2.7 (page 60-63).<BR>
*
* @see PdfObject
* @see PdfDictionary
*/
public class PdfStream extends PdfDictionary {
// membervariables
/**
* A possible compression level.
*
* @since 2.1.3
*/
public static final int DEFAULT_COMPRESSION = -1;
/**
* A possible compression level.
*
* @since 2.1.3
*/
public static final int NO_COMPRESSION = 0;
/**
* A possible compression level.
*
* @since 2.1.3
*/
public static final int BEST_COMPRESSION = 9;
static final byte[] STARTSTREAM = DocWriter.getISOBytes("stream\n");
static final byte[] ENDSTREAM = DocWriter.getISOBytes("\nendstream");
/**
* is the stream compressed?
*/
protected boolean compressed = false;
/**
* The level of compression.
*
* @since 2.1.3
*/
protected int compressionLevel = NO_COMPRESSION;
protected ByteArrayOutputStream streamBytes = null;
protected InputStream inputStream;
protected PdfIndirectReference ref;
protected long inputStreamLength = -1;
protected PdfWriter writer;
protected long rawLength;
// constructors
/**
* Constructs a <CODE>PdfStream</CODE>-object.
*
* @param bytes content of the new <CODE>PdfObject</CODE> as an array of <CODE>byte</CODE>.
*/
public PdfStream(byte[] bytes) {
super();
type = STREAM;
this.bytes = bytes;
rawLength = bytes.length;
put(PdfName.LENGTH, new PdfNumber(bytes.length));
}
/**
* Constructs a <CODE>PdfStream</CODE>-object.
*/
protected PdfStream() {
super();
type = STREAM;
}
// public int getStreamLength(PdfWriter writer) {
// if (dicBytes == null)
// toPdf(writer);
// if (streamBytes != null)
// return streamBytes.size() + dicBytes.length + SIZESTREAM;
// else
// return bytes.length + dicBytes.length + SIZESTREAM;
// }
protected void superToPdf(PdfWriter writer, OutputStream os) throws IOException {
super.toPdf(writer, os);
}
/**
* Writes the data content to an <CODE>OutputStream</CODE>.
*
* @param os the destination to write to
* @throws IOException on error
*/
public void writeContent(OutputStream os) throws IOException {
if (streamBytes != null) {
streamBytes.writeTo(os);
} else if (bytes != null) {
os.write(bytes);
}
}
/**
* @see org.openpdf.text.pdf.PdfObject#toString()
*/
public String toString() {
if (get(PdfName.TYPE) == null) {
return "Stream";
}
return "Stream of type: " + get(PdfName.TYPE);
}
/**
* Compresses the stream.
*
* @param compressionLevel the compression level (0 = best speed, 9 = best compression, -1 is default)
* @since 2.1.3
*/
public void flateCompress(int compressionLevel) {
// NO_COMPRESSION: the stream stays readable (used for deterministic, diffable output)
if (!Document.compress || compressionLevel == NO_COMPRESSION) {
return;
}
// check if the flateCompress-method has already been
if (compressed) {
return;
}
this.compressionLevel = compressionLevel;
if (inputStream != null) {
compressed = true;
return;
}
// check if a filter already exists
PdfObject filter = get(PdfName.FILTER);
if (filter != null) {
if (filter.isName()) {
if (PdfName.FLATEDECODE.equals(filter)) {
return;
}
} else if (filter.isArray()) {
if (((PdfArray) filter).contains(PdfName.FLATEDECODE)) {
return;
}
} else {
throw new RuntimeException(MessageLocalization.getComposedMessage(
"stream.could.not.be.compressed.filter.is.not.a.name.or.array"));
}
}
try {
// compress
ByteArrayOutputStream stream = new ByteArrayOutputStream();
Deflater deflater = new Deflater(compressionLevel);
DeflaterOutputStream zip = new DeflaterOutputStream(stream, deflater);
if (streamBytes != null) {
streamBytes.writeTo(zip);
} else {
zip.write(bytes);
}
zip.close();
deflater.end();
// update the object
streamBytes = stream;
bytes = null;
put(PdfName.LENGTH, new PdfNumber(streamBytes.size()));
if (filter == null) {
put(PdfName.FILTER, PdfName.FLATEDECODE);
} else {
PdfArray filters = new PdfArray(filter);
filters.add(PdfName.FLATEDECODE);
put(PdfName.FILTER, filters);
}
compressed = true;
} catch (IOException ioe) {
throw new ExceptionConverter(ioe);
}
}
/**
* @see org.openpdf.text.pdf.PdfDictionary#toPdf(org.openpdf.text.pdf.PdfWriter, java.io.OutputStream)
*/
public void toPdf(PdfWriter writer, OutputStream os) throws IOException {
if (inputStream != null && compressed) {
put(PdfName.FILTER, PdfName.FLATEDECODE);
}
superToPdf(writer, os);
os.write(STARTSTREAM);
if (inputStream != null) {
rawLength = 0;
DeflaterOutputStream def = null;
OutputStreamCounter osc = new OutputStreamCounter(os);
OutputStream fout = osc;
Deflater deflater = null;
if (compressed) {
deflater = new Deflater(compressionLevel);
fout = def = new DeflaterOutputStream(fout, deflater, 0x8000);
}
byte[] buf = new byte[4192];
while (true) {
int n = inputStream.read(buf);
if (n <= 0) {
break;
}
fout.write(buf, 0, n);
rawLength += n;
}
if (def != null) {
def.finish();
deflater.end();
}
inputStreamLength = osc.getCounter();
} else {
if (streamBytes != null) {
streamBytes.writeTo(os);
} else {
os.write(bytes);
}
}
os.write(ENDSTREAM);
}
}