/* * $Id: PdfStream.java,v 1.57 2005/11/01 12:27:05 psoares33 Exp $ * $Name: $ * * 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: * http://www.lowagie.com/iText/ */ package com.lowagie.text.pdf; import java.io.ByteArrayOutputStream; import java.io.OutputStream; import java.io.InputStream; import java.io.IOException; import java.util.zip.DeflaterOutputStream; import java.util.zip.Deflater; import com.lowagie.text.Document; import com.lowagie.text.DocWriter; import com.lowagie.text.ExceptionConverter; /** * 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 1.3' * section 4.8 (page 41-53).
* * @see PdfObject * @see PdfDictionary */ public class PdfStream extends PdfDictionary { // membervariables /** is the stream compressed? */ protected boolean compressed = false; 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 contructor {@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("writeLength() can only be called in a contructed PdfStream(InputStream,PdfWriter)."); if (inputStreamLength == -1) throw new IOException("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() { if (!Document.compress) return; // check if the flateCompress-method has already been if (compressed) { return; } if (inputStream != null) { compressed = true; return; } // check if a filter already exists PdfObject filter = get(PdfName.FILTER); if (filter != null) { if (filter.isName() && ((PdfName) filter).compareTo(PdfName.FLATEDECODE) == 0) { return; } else if (filter.isArray() && ((PdfArray) filter).contains(PdfName.FLATEDECODE)) { return; } else { throw new RuntimeException("Stream could not be compressed: filter is not a name or array."); } } try { // compress ByteArrayOutputStream stream = new ByteArrayOutputStream(); DeflaterOutputStream zip = new DeflaterOutputStream(stream); if (streamBytes != null) streamBytes.writeTo(zip); else zip.write(bytes); zip.close(); // 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); } } // 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.lowagie.text.pdf.PdfDictionary#toPdf(com.lowagie.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); PdfEncryption crypto = null; if (writer != null) crypto = writer.getEncryption(); if (crypto != null) crypto.prepareKey(); if (inputStream != null) { rawLength = 0; DeflaterOutputStream def = null; OutputStreamCounter osc = new OutputStreamCounter(os); OutputStream fout = osc; if (crypto != null) fout = new PdfEncryptionStream(fout, crypto); if (compressed) fout = def = new DeflaterOutputStream(fout, new Deflater(Deflater.BEST_COMPRESSION), 0x8000); byte buf[] = new byte[0x10000]; while (true) { int n = inputStream.read(buf); if (n <= 0) break; fout.write(buf, 0, n); rawLength += n; } if (def != null) def.finish(); inputStreamLength = osc.getCounter(); } else { if (crypto == null) { if (streamBytes != null) streamBytes.writeTo(os); else os.write(bytes); } else { byte b[]; if (streamBytes != null) { b = streamBytes.toByteArray(); crypto.encryptRC4(b); } else { b = new byte[bytes.length]; crypto.encryptRC4(bytes, b); } os.write(b); } } 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); } }