com.itextpdf.text.pdf.PdfStream Maven / Gradle / Ivy
/*
*
* This file is part of the iText (R) project.
* Copyright (c) 1998-2016 iText Group NV
* Authors: Bruno Lowagie, Paulo Soares, et al.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License version 3
* as published by the Free Software Foundation with the addition of the
* following permission added to Section 15 as permitted in Section 7(a):
* FOR ANY PART OF THE COVERED WORK IN WHICH THE COPYRIGHT IS OWNED BY
* ITEXT GROUP. ITEXT GROUP DISCLAIMS THE WARRANTY OF NON INFRINGEMENT
* OF THIRD PARTY RIGHTS
*
* This program 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 Affero General Public License for more details.
* You should have received a copy of the GNU Affero General Public License
* along with this program; if not, see http://www.gnu.org/licenses or write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA, 02110-1301 USA, or download the license from the following URL:
* http://itextpdf.com/terms-of-use/
*
* The interactive user interfaces in modified source and object code versions
* of this program must display Appropriate Legal Notices, as required under
* Section 5 of the GNU Affero General Public License.
*
* In accordance with Section 7(b) of the GNU Affero General Public License,
* a covered work must retain the producer line in every PDF that is created
* or manipulated using iText.
*
* You can be released from the requirements of the license by purchasing
* a commercial license. Buying such a license is mandatory as soon as you
* develop commercial activities involving the iText software without
* disclosing the source code of your own applications.
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* For more information, please contact iText Software Corp. at this
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*/
package com.itextpdf.text.pdf;
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;
import com.itextpdf.text.error_messages.MessageLocalization;
import com.itextpdf.text.DocWriter;
import com.itextpdf.text.Document;
import com.itextpdf.text.ExceptionConverter;
import com.itextpdf.text.pdf.internal.PdfIsoKeys;
/**
* PdfStream is the Pdf stream object.
*
* 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.
* A stream consists of a dictionary that describes a sequence of characters, followed by
* the keyword stream, followed by zero or more lines of characters, followed by
* the keyword endstream.
* All streams must be PdfIndirectObjects. The stream dictionary must be a direct
* object. The keyword stream that follows the stream dictionary should be followed by
* a carriage return and linefeed or just a linefeed.
* Remark: In this version only the FLATEDECODE-filter is supported.
* This object is described in the 'Portable Document Format Reference Manual version 1.7'
* section 3.2.7 (page 60-63).
*
* @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_SPEED = 1;
/**
* A possible compression level.
* @since 2.1.3
*/
public static final int BEST_COMPRESSION = 9;
/** 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 int inputStreamLength = -1;
protected PdfWriter writer;
protected int rawLength;
static final byte STARTSTREAM[] = DocWriter.getISOBytes("stream\n");
static final byte ENDSTREAM[] = DocWriter.getISOBytes("\nendstream");
static final int SIZESTREAM = STARTSTREAM.length + ENDSTREAM.length;
// constructors
/**
* Constructs a PdfStream-object.
*
* @param bytes content of the new PdfObject as an array of byte.
*/
public PdfStream(byte[] bytes) {
super();
type = STREAM;
this.bytes = bytes;
rawLength = bytes.length;
put(PdfName.LENGTH, new PdfNumber(bytes.length));
}
/**
* Creates an efficient stream. No temporary array is ever created. The InputStream
* is totally consumed but is not closed. The general usage is:
*
*
* InputStream in = ...;
* PdfStream stream = new PdfStream(in, writer);
* stream.flateCompress();
* writer.addToBody(stream);
* stream.writeLength();
* in.close();
*
* @param inputStream the data to write to this stream
* @param writer the PdfWriter for this stream
*/
public PdfStream(InputStream inputStream, PdfWriter writer) {
super();
type = STREAM;
this.inputStream = inputStream;
this.writer = writer;
ref = writer.getPdfIndirectReference();
put(PdfName.LENGTH, ref);
}
/**
* Constructs a PdfStream-object.
*/
protected PdfStream() {
super();
type = STREAM;
}
/**
* Writes the stream length to the PdfWriter.
*
* This method must be called and can only be called if the constructor {@link #PdfStream(InputStream,PdfWriter)}
* is used to create the stream.
* @throws IOException on error
* @see #PdfStream(InputStream,PdfWriter)
*/
public void writeLength() throws IOException {
if (inputStream == null)
throw new UnsupportedOperationException(MessageLocalization.getComposedMessage("writelength.can.only.be.called.in.a.contructed.pdfstream.inputstream.pdfwriter"));
if (inputStreamLength == -1)
throw new IOException(MessageLocalization.getComposedMessage("writelength.can.only.be.called.after.output.of.the.stream.body"));
writer.addToBody(new PdfNumber(inputStreamLength), ref, false);
}
/**
* Gets the raw length of the stream.
* @return the raw length of the stream
*/
public int getRawLength() {
return rawLength;
}
/**
* Compresses the stream.
*/
public void flateCompress() {
flateCompress(DEFAULT_COMPRESSION);
}
/**
* 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) {
if (!Document.compress)
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 = PdfReader.getPdfObject(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(0, PdfName.FLATEDECODE);
put(PdfName.FILTER, filters);
}
compressed = true;
}
catch(IOException ioe) {
throw new ExceptionConverter(ioe);
}
}
// 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);
}
/**
* @see com.itextpdf.text.pdf.PdfDictionary#toPdf(com.itextpdf.text.pdf.PdfWriter, java.io.OutputStream)
*/
public void toPdf(PdfWriter writer, OutputStream os) throws IOException {
if (inputStream != null && compressed)
put(PdfName.FILTER, PdfName.FLATEDECODE);
PdfEncryption crypto = null;
if (writer != null)
crypto = writer.getEncryption();
if (crypto != null) {
PdfObject filter = get(PdfName.FILTER);
if (filter != null) {
if (PdfName.CRYPT.equals(filter))
crypto = null;
else if (filter.isArray()) {
PdfArray a = (PdfArray)filter;
if (!a.isEmpty() && PdfName.CRYPT.equals(a.getPdfObject(0)))
crypto = null;
}
}
}
PdfObject nn = get(PdfName.LENGTH);
if (crypto != null && nn != null && nn.isNumber()) {
int sz = ((PdfNumber)nn).intValue();
put(PdfName.LENGTH, new PdfNumber(crypto.calculateStreamSize(sz)));
superToPdf(writer, os);
put(PdfName.LENGTH, nn);
}
else
superToPdf(writer, os);
PdfWriter.checkPdfIsoConformance(writer, PdfIsoKeys.PDFISOKEY_STREAM, this);
os.write(STARTSTREAM);
if (inputStream != null) {
rawLength = 0;
DeflaterOutputStream def = null;
OutputStreamCounter osc = new OutputStreamCounter(os);
OutputStreamEncryption ose = null;
OutputStream fout = osc;
if (crypto != null && !crypto.isEmbeddedFilesOnly())
fout = ose = crypto.getEncryptionStream(fout);
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();
}
if (ose != null)
ose.finish();
inputStreamLength = (int)osc.getCounter();
}
else {
if (crypto != null && !crypto.isEmbeddedFilesOnly()) {
byte b[];
if (streamBytes != null) {
b = crypto.encryptByteArray(streamBytes.toByteArray());
}
else {
b = crypto.encryptByteArray(bytes);
}
os.write(b);
}
else {
if (streamBytes != null)
streamBytes.writeTo(os);
else
os.write(bytes);
}
}
os.write(ENDSTREAM);
}
/**
* Writes the data content to an OutputStream.
* @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 com.itextpdf.text.pdf.PdfObject#toString()
*/
public String toString() {
if (get(PdfName.TYPE) == null) return "Stream";
return "Stream of type: " + get(PdfName.TYPE);
}
}