1 /*
2 * $Id: PdfStream.java 3538 2008-07-08 13:08:04Z blowagie $
3 *
4 * Copyright 1999, 2000, 2001, 2002 Bruno Lowagie
5 *
6 * The contents of this file are subject to the Mozilla Public License Version 1.1
7 * (the "License"); you may not use this file except in compliance with the License.
8 * You may obtain a copy of the License at http://www.mozilla.org/MPL/
9 *
10 * Software distributed under the License is distributed on an "AS IS" basis,
11 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
12 * for the specific language governing rights and limitations under the License.
13 *
14 * The Original Code is 'iText, a free JAVA-PDF library'.
15 *
16 * The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
17 * the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
18 * All Rights Reserved.
19 * Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
20 * are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
21 *
22 * Contributor(s): all the names of the contributors are added in the source code
23 * where applicable.
24 *
25 * Alternatively, the contents of this file may be used under the terms of the
26 * LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
27 * provisions of LGPL are applicable instead of those above. If you wish to
28 * allow use of your version of this file only under the terms of the LGPL
29 * License and not to allow others to use your version of this file under
30 * the MPL, indicate your decision by deleting the provisions above and
31 * replace them with the notice and other provisions required by the LGPL.
32 * If you do not delete the provisions above, a recipient may use your version
33 * of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
34 *
35 * This library is free software; you can redistribute it and/or modify it
36 * under the terms of the MPL as stated above or under the terms of the GNU
37 * Library General Public License as published by the Free Software Foundation;
38 * either version 2 of the License, or any later version.
39 *
40 * This library is distributed in the hope that it will be useful, but WITHOUT
41 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
42 * FOR A PARTICULAR PURPOSE. See the GNU Library general Public License for more
43 * details.
44 *
45 * If you didn't download this code from the following link, you should check if
46 * you aren't using an obsolete version:
47 * http://www.lowagie.com/iText/
48 */
49
50 package com.lowagie.text.pdf;
51
52 import java.io.ByteArrayOutputStream;
53 import java.io.IOException;
54 import java.io.InputStream;
55 import java.io.OutputStream;
56 import java.util.zip.Deflater;
57 import java.util.zip.DeflaterOutputStream;
58
59 import com.lowagie.text.DocWriter;
60 import com.lowagie.text.Document;
61 import com.lowagie.text.ExceptionConverter;
62 import java.util.ArrayList;
63
64 /**
65 * <CODE>PdfStream</CODE> is the Pdf stream object.
66 * <P>
67 * A stream, like a string, is a sequence of characters. However, an application can
68 * read a small portion of a stream at a time, while a string must be read in its entirety.
69 * For this reason, objects with potentially large amounts of data, such as images and
70 * page descriptions, are represented as streams.<BR>
71 * A stream consists of a dictionary that describes a sequence of characters, followed by
72 * the keyword <B>stream</B>, followed by zero or more lines of characters, followed by
73 * the keyword <B>endstream</B>.<BR>
74 * All streams must be <CODE>PdfIndirectObject</CODE>s. The stream dictionary must be a direct
75 * object. The keyword <B>stream</B> that follows the stream dictionary should be followed by
76 * a carriage return and linefeed or just a linefeed.<BR>
77 * Remark: In this version only the FLATEDECODE-filter is supported.<BR>
78 * This object is described in the 'Portable Document Format Reference Manual version 1.7'
79 * section 3.2.7 (page 60-63).<BR>
80 *
81 * @see PdfObject
82 * @see PdfDictionary
83 */
84
85 public class PdfStream extends PdfDictionary {
86
87 // membervariables
88
89 /**
90 * A possible compression level.
91 * @since 2.1.3
92 */
93 public static final int DEFAULT_COMPRESSION = -1;
94 /**
95 * A possible compression level.
96 * @since 2.1.3
97 */
98 public static final int NO_COMPRESSION = 0;
99 /**
100 * A possible compression level.
101 * @since 2.1.3
102 */
103 public static final int BEST_SPEED = 1;
104 /**
105 * A possible compression level.
106 * @since 2.1.3
107 */
108 public static final int BEST_COMPRESSION = 9;
109
110
111 /** is the stream compressed? */
112 protected boolean compressed = false;
113 /**
114 * The level of compression.
115 * @since 2.1.3
116 */
117 protected int compressionLevel = NO_COMPRESSION;
118
119 protected ByteArrayOutputStream streamBytes = null;
120 protected InputStream inputStream;
121 protected PdfIndirectReference ref;
122 protected int inputStreamLength = -1;
123 protected PdfWriter writer;
124 protected int rawLength;
125
126 static final byte STARTSTREAM[] = DocWriter.getISOBytes("stream\n");
127 static final byte ENDSTREAM[] = DocWriter.getISOBytes("\nendstream");
128 static final int SIZESTREAM = STARTSTREAM.length + ENDSTREAM.length;
129
130 // constructors
131
132 /**
133 * Constructs a <CODE>PdfStream</CODE>-object.
134 *
135 * @param bytes content of the new <CODE>PdfObject</CODE> as an array of <CODE>byte</CODE>.
136 */
137
138 public PdfStream(byte[] bytes) {
139 super();
140 type = STREAM;
141 this.bytes = bytes;
142 rawLength = bytes.length;
143 put(PdfName.LENGTH, new PdfNumber(bytes.length));
144 }
145
146 /**
147 * Creates an efficient stream. No temporary array is ever created. The <CODE>InputStream</CODE>
148 * is totally consumed but is not closed. The general usage is:
149 * <p>
150 * <pre>
151 * InputStream in = ...;
152 * PdfStream stream = new PdfStream(in, writer);
153 * stream.flateCompress();
154 * writer.addToBody(stream);
155 * stream.writeLength();
156 * in.close();
157 * </pre>
158 * @param inputStream the data to write to this stream
159 * @param writer the <CODE>PdfWriter</CODE> for this stream
160 */
161 public PdfStream(InputStream inputStream, PdfWriter writer) {
162 super();
163 type = STREAM;
164 this.inputStream = inputStream;
165 this.writer = writer;
166 ref = writer.getPdfIndirectReference();
167 put(PdfName.LENGTH, ref);
168 }
169
170 /**
171 * Constructs a <CODE>PdfStream</CODE>-object.
172 */
173
174 protected PdfStream() {
175 super();
176 type = STREAM;
177 }
178
179 /**
180 * Writes the stream length to the <CODE>PdfWriter</CODE>.
181 * <p>
182 * This method must be called and can only be called if the constructor {@link #PdfStream(InputStream,PdfWriter)}
183 * is used to create the stream.
184 * @throws IOException on error
185 * @see #PdfStream(InputStream,PdfWriter)
186 */
187 public void writeLength() throws IOException {
188 if (inputStream == null)
189 throw new UnsupportedOperationException("writeLength() can only be called in a contructed PdfStream(InputStream,PdfWriter).");
190 if (inputStreamLength == -1)
191 throw new IOException("writeLength() can only be called after output of the stream body.");
192 writer.addToBody(new PdfNumber(inputStreamLength), ref, false);
193 }
194
195 /**
196 * Gets the raw length of the stream.
197 * @return the raw length of the stream
198 */
199 public int getRawLength() {
200 return rawLength;
201 }
202
203 /**
204 * Compresses the stream.
205 */
206 public void flateCompress() {
207 flateCompress(DEFAULT_COMPRESSION);
208 }
209
210 /**
211 * Compresses the stream.
212 * @param compressionLevel the compression level (0 = best speed, 9 = best compression, -1 is default)
213 * @since 2.1.3
214 */
215 public void flateCompress(int compressionLevel) {
216 if (!Document.compress)
217 return;
218 // check if the flateCompress-method has already been
219 if (compressed) {
220 return;
221 }
222 this.compressionLevel = compressionLevel;
223 if (inputStream != null) {
224 compressed = true;
225 return;
226 }
227 // check if a filter already exists
228 PdfObject filter = PdfReader.getPdfObject(get(PdfName.FILTER));
229 if (filter != null) {
230 if (filter.isName()) {
231 if (PdfName.FLATEDECODE.equals(filter))
232 return;
233 }
234 else if (filter.isArray()) {
235 if (((PdfArray) filter).contains(PdfName.FLATEDECODE))
236 return;
237 }
238 else {
239 throw new RuntimeException("Stream could not be compressed: filter is not a name or array.");
240 }
241 }
242 try {
243 // compress
244 ByteArrayOutputStream stream = new ByteArrayOutputStream();
245 DeflaterOutputStream zip = new DeflaterOutputStream(stream, new Deflater(compressionLevel));
246 if (streamBytes != null)
247 streamBytes.writeTo(zip);
248 else
249 zip.write(bytes);
250 zip.close();
251 // update the object
252 streamBytes = stream;
253 bytes = null;
254 put(PdfName.LENGTH, new PdfNumber(streamBytes.size()));
255 if (filter == null) {
256 put(PdfName.FILTER, PdfName.FLATEDECODE);
257 }
258 else {
259 PdfArray filters = new PdfArray(filter);
260 filters.add(PdfName.FLATEDECODE);
261 put(PdfName.FILTER, filters);
262 }
263 compressed = true;
264 }
265 catch(IOException ioe) {
266 throw new ExceptionConverter(ioe);
267 }
268 }
269
270 // public int getStreamLength(PdfWriter writer) {
271 // if (dicBytes == null)
272 // toPdf(writer);
273 // if (streamBytes != null)
274 // return streamBytes.size() + dicBytes.length + SIZESTREAM;
275 // else
276 // return bytes.length + dicBytes.length + SIZESTREAM;
277 // }
278
279 protected void superToPdf(PdfWriter writer, OutputStream os) throws IOException {
280 super.toPdf(writer, os);
281 }
282
283 /**
284 * @see com.lowagie.text.pdf.PdfDictionary#toPdf(com.lowagie.text.pdf.PdfWriter, java.io.OutputStream)
285 */
286 public void toPdf(PdfWriter writer, OutputStream os) throws IOException {
287 if (inputStream != null && compressed)
288 put(PdfName.FILTER, PdfName.FLATEDECODE);
289 PdfEncryption crypto = null;
290 if (writer != null)
291 crypto = writer.getEncryption();
292 if (crypto != null) {
293 PdfObject filter = get(PdfName.FILTER);
294 if (filter != null) {
295 if (PdfName.CRYPT.equals(filter))
296 crypto = null;
297 else if (filter.isArray()) {
298 ArrayList af = ((PdfArray)filter).getArrayList();
299 if (!af.isEmpty() && PdfName.CRYPT.equals(af.get(0)))
300 crypto = null;
301 }
302 }
303 }
304 PdfObject nn = get(PdfName.LENGTH);
305 if (crypto != null && nn != null && nn.isNumber()) {
306 int sz = ((PdfNumber)nn).intValue();
307 put(PdfName.LENGTH, new PdfNumber(crypto.calculateStreamSize(sz)));
308 superToPdf(writer, os);
309 put(PdfName.LENGTH, nn);
310 }
311 else
312 superToPdf(writer, os);
313 os.write(STARTSTREAM);
314 if (inputStream != null) {
315 rawLength = 0;
316 DeflaterOutputStream def = null;
317 OutputStreamCounter osc = new OutputStreamCounter(os);
318 OutputStreamEncryption ose = null;
319 OutputStream fout = osc;
320 if (crypto != null && !crypto.isEmbeddedFilesOnly())
321 fout = ose = crypto.getEncryptionStream(fout);
322 if (compressed)
323 fout = def = new DeflaterOutputStream(fout, new Deflater(compressionLevel), 0x8000);
324
325 byte buf[] = new byte[4192];
326 while (true) {
327 int n = inputStream.read(buf);
328 if (n <= 0)
329 break;
330 fout.write(buf, 0, n);
331 rawLength += n;
332 }
333 if (def != null)
334 def.finish();
335 if (ose != null)
336 ose.finish();
337 inputStreamLength = osc.getCounter();
338 }
339 else {
340 if (crypto != null && !crypto.isEmbeddedFilesOnly()) {
341 byte b[];
342 if (streamBytes != null) {
343 b = crypto.encryptByteArray(streamBytes.toByteArray());
344 }
345 else {
346 b = crypto.encryptByteArray(bytes);
347 }
348 os.write(b);
349 }
350 else {
351 if (streamBytes != null)
352 streamBytes.writeTo(os);
353 else
354 os.write(bytes);
355 }
356 }
357 os.write(ENDSTREAM);
358 }
359
360 /**
361 * Writes the data content to an <CODE>OutputStream</CODE>.
362 * @param os the destination to write to
363 * @throws IOException on error
364 */
365 public void writeContent(OutputStream os) throws IOException {
366 if (streamBytes != null)
367 streamBytes.writeTo(os);
368 else if (bytes != null)
369 os.write(bytes);
370 }
371
372 /**
373 * @see com.lowagie.text.pdf.PdfObject#toString()
374 */
375 public String toString() {
376 if (get(PdfName.TYPE) == null) return "Stream";
377 return "Stream of type: " + get(PdfName.TYPE);
378 }
379 }
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