de.intarsys.pdf.parser.COSDocumentParser Maven / Gradle / Ivy
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This is a fork of http://sourceforge.net/projects/jpodlib/ as development seems to be frozen.
We're providing some bug fixes along with deployments to maven.
/*
* Copyright (c) 2007, intarsys consulting GmbH
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* - Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* - Neither the name of intarsys nor the names of its contributors may be used
* to endorse or promote products derived from this software without specific
* prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
package de.intarsys.pdf.parser;
import de.intarsys.pdf.cos.COSDictionary;
import de.intarsys.pdf.cos.COSDocumentElement;
import de.intarsys.pdf.cos.COSIndirectObject;
import de.intarsys.pdf.cos.COSInteger;
import de.intarsys.pdf.cos.COSName;
import de.intarsys.pdf.cos.COSNull;
import de.intarsys.pdf.cos.COSObject;
import de.intarsys.pdf.cos.COSObjectKey;
import de.intarsys.pdf.crypt.ISystemSecurityHandler;
import de.intarsys.pdf.st.STDocument;
import de.intarsys.tools.randomaccess.IRandomAccess;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
* A parser for PDF data streams.
*
*
* The parser will create a object representation of the pdf document using COS
* level objects.
*
*
*
* The parser is a one pass, read everything implementation.
*
*/
public class COSDocumentParser extends PDFParser {
/**
* use a buffer large than specified by the spec. we already had documents
* with whitespace padding > 1024 bytes!
*/
public static final int SEARCH_BUFFER_SIZE = 2048;
private STDocument doc;
public COSDocumentParser(STDocument doc) {
this.doc = doc;
}
/*
* create a COS reference out of the objects in the parsers lookahead see
* PDF Reference v1.4, chapter 3.2.9 Indirect objects COSReference ::=
* objNum genNum "R"
*
* @return the reference object created
*
* @throws IOException @throws COSLoadException
*/
@Override
protected COSIndirectObject createObjectReference(IRandomAccess input) throws IOException, COSLoadException {
COSObject obj1 = lookaheadPop();
COSObject obj2 = lookaheadPop();
if (!(obj1 instanceof COSInteger) || !(obj2 instanceof COSInteger)) {
COSLoadError e = new COSLoadError("illegal reference at character index " + input.getOffset());
handleError(e);
}
int objectNumber = ((COSInteger) obj1).intValue();
int generationNumber = ((COSInteger) obj2).intValue();
return getDoc().getObjectReference(objectNumber, generationNumber);
}
public STDocument getDoc() {
return doc;
}
public boolean isTokenXRefAt(IRandomAccess input, int offset) throws IOException {
input.seek(offset);
readSpaces(input);
byte[] token = new byte[4];
input.read(token);
return Arrays.equals(token, PDFParser.TOKEN_xref);
}
/**
* read a pdf style object from the input. see PDF Reference v1.4, chapter
* 3.2.9 Indirect Objects COSIndirectObject ::= ObjNum GenNum "obj" Object
* "endobj"
*
* @return The parsed object.
* @throws IOException
* @throws COSLoadException
*/
public COSObject parseIndirectObject(IRandomAccess input, ISystemSecurityHandler securityHandler)
throws IOException, COSLoadException {
COSObjectKey key = parseIndirectObjectKey(input);
// this may be called recursive in a stream for its length
COSObjectKey oldObjectKey = getObjectKey();
ISystemSecurityHandler oldSecurityHandler = getSecurityHandler();
try {
setObjectKey(key);
setSecurityHandler(securityHandler);
COSObject object = parseIndirectObjectBody(input);
if (object == null) {
object = COSNull.NULL;
}
return object;
} finally {
setObjectKey(oldObjectKey);
setSecurityHandler(oldSecurityHandler);
}
}
protected COSObject parseIndirectObjectBody(IRandomAccess input) throws IOException, COSLoadException {
byte[] token;
COSDocumentElement element = parseObject(input);
if (element == null) {
COSLoadError e = new COSLoadError("object expected at character index " + input.getOffset());
handleError(e);
} else {
if (element.isReference()) {
COSLoadError e =
new COSLoadError("object reference not allowed in a indirect object at character index " + input
.getOffset());
handleError(e);
}
if (check) {
List messages = new ArrayList();
token = readToken(input, messages, false);
// todo 2 kkr add check for additional whitespace after
// endstream
// before endobj
if (!messages.isEmpty()
&& !(messages.size() == 1 && messages.contains(C_TOKEN_ADDWSB))
&& !(messages.size() == 1 && messages.contains(C_TOKEN_ADDWSA2))) {
COSLoadWarning pwarn = new COSLoadWarning(C_WARN_SINGLEEOL_OBJ);
pwarn.setHint(Long.valueOf(input.getOffset()));
handleWarning(pwarn);
}
} else {
token = readToken(input);
}
if (token == null) {
COSLoadError e = new COSLoadError("unexpected end of file");
handleError(e);
}
if (!Arrays.equals(token, TOKEN_endobj)) {
input.seekBy(-token.length);
COSLoadWarning w = new COSLoadWarning(C_WARN_ENDOBJ_MISSING);
handleWarning(w);
}
}
return (COSObject) element;
}
protected COSObjectKey parseIndirectObjectKey(IRandomAccess input) throws IOException, COSLoadException {
byte[] token;
// pdfa compliance here, must verify the existence of a single space
// between
// object number, generation and obj keyword
List messages = new ArrayList();
// object number
if (check) {
token = readToken(input, messages, true);
} else {
token = readToken(input);
}
if (token == null) {
COSLoadError e = new COSLoadError("unexpected end of file");
handleError(e);
}
int objNumber = 0;
try {
objNumber = Integer.parseInt(new String(token));
if (messages.size() > 1) {
COSLoadWarning pwarn = new COSLoadWarning(C_WARN_SINGLESPACE_OBJ);
pwarn.setHint(Long.valueOf(input.getOffset()));
handleWarning(pwarn);
}
} catch (NumberFormatException ignored) {
COSLoadError e = new COSLoadError("invalid object number at character index " + input.getOffset());
handleError(e);
}
// generation number
messages.clear();
if (check) {
token = readToken(input, messages, true);
} else {
token = readToken(input);
}
if (token == null) {
COSLoadError e = new COSLoadError("unexpected end of file");
handleError(e);
}
int genNumber = 0;
try {
genNumber = Integer.parseInt(new String(token));
if (messages.size() > 1) {
COSLoadWarning pwarn = new COSLoadWarning(C_WARN_SINGLESPACE_OBJ);
pwarn.setHint(Long.valueOf(input.getOffset()));
handleWarning(pwarn);
}
} catch (NumberFormatException ignored) {
COSLoadError e = new COSLoadError("invalid generation number at character index " + input.getOffset());
handleError(e);
}
// obj keyword
messages.clear();
if (check) {
token = readToken(input, messages, true);
} else {
token = readToken(input);
}
if (token == null) {
COSLoadError e = new COSLoadError("unexpected end of file");
handleError(e);
}
if (!Arrays.equals(token, TOKEN_obj)) {
input.seekBy(-token.length);
COSLoadError e =
new COSLoadError("file format error, obj expected at character index " + input.getOffset());
handleError(e);
}
if (check) {
if (!messages.isEmpty()) {
COSLoadWarning pwarn = new COSLoadWarning(C_WARN_SINGLESPACE_OBJ);
pwarn.setHint(Long.valueOf(input.getOffset()));
handleWarning(pwarn);
}
if (readEOL(input) > 1) {
COSLoadWarning pwarn = new COSLoadWarning(C_WARN_SINGLEEOL_OBJ);
pwarn.setHint(Long.valueOf(input.getOffset()));
handleWarning(pwarn);
}
} else {
readSpaces(input);
}
return new COSObjectKey(objNumber, genNumber);
}
/**
* the startxref value.
*
* @return the startxref value
* @throws IOException
* @throws COSLoadException
*/
public int parseStartXRef(IRandomAccess input) throws IOException, COSLoadException {
readSpaces(input);
byte[] token = new byte[9];
input.read(token);
if (!Arrays.equals(token, PDFParser.TOKEN_startxref)) {
COSLoadError e =
new COSLoadError("file format error. 'startxref' expected at offset:" + (input.getOffset() - 9));
handleError(e);
}
return readInteger(input, true);
}
/**
* parse the trailer section from the current stream position. see PDF
* Reference v1.4, chapter 3.4.4 File Trailer DocumentTrailer ::= "trailer"
* COSDict "startxref" COSNumber
*
* @return the trailer dictionary
* @throws IOException
* @throws COSLoadException
*/
public COSDictionary parseTrailer(IRandomAccess input) throws IOException, COSLoadException {
byte[] token = new byte[7];
int bytesRead = input.read(token);
if (!Arrays.equals(token, TOKEN_trailer)) {
if (bytesRead > 0) {
input.seekBy(-bytesRead);
}
COSLoadError e =
new COSLoadError("file format error. 'trailer' expected at character index " + input.getOffset());
handleError(e);
}
readSpaces(input);
COSDictionary trailerDict = (COSDictionary) parseObjectDictionary(input);
readSpaces(input);
return trailerDict;
}
/**
* Searches the offset to the first trailer in the last SEARCH_BUFFER_SIZE
* bytes of the document. The search goes backwards starting with the last
* byte.
*
* @return the offset to the first trailer found
* @throws IOException
* @throws COSLoadException
*/
public int searchLastStartXRef(IRandomAccess input) throws IOException, COSLoadException {
long startOffset = input.getLength() - SEARCH_BUFFER_SIZE;
if (startOffset < 0) {
startOffset = 0;
}
input.seek(startOffset);
byte[] buffer = new byte[SEARCH_BUFFER_SIZE];
int bytesRead = input.read(buffer);
boolean found = false;
int bufferOffset;
for (bufferOffset = bytesRead - TOKEN_startxref.length; bufferOffset > 0; bufferOffset--) {
for (int j = 0; j < TOKEN_startxref.length; j++) {
if (buffer[bufferOffset + j] == TOKEN_startxref[j]) {
found = true;
} else {
found = false;
break;
}
}
if (found) {
break;
}
}
if (found) {
long startXRefOffset = startOffset + bufferOffset;
input.seek(startXRefOffset);
return parseStartXRef(input);
}
COSLoadError e =
new COSLoadError("no startxref found in the last " + SEARCH_BUFFER_SIZE + " bytes of the document");
handleError(e);
return -1;
}
/**
* @param input
* @return Returns the offset of the dictionary with linearization
* parameters if any.
* @throws IOException
* @throws COSLoadException
* @deprecated Don't use this anymore
*
* Returns the offset of the dictionary with linearization
* parameters if any. Returns -1 otherwise.
*/
@Deprecated
public int searchLinearized(IRandomAccess input) throws IOException, COSLoadException {
long oldOffset = input.getOffset();
int result = -1;
input.seek(0);
parseComment(input); // file header
int next = input.read();
while (true) {
if (next == -1) {
break;
}
if ((next == ' ') || isWhitespace(next)) { // performance shortcut
next = input.read();
continue;
}
input.seekBy(-1);
if (isDigit(next)) {
result = (int) input.getOffset();
COSDocumentElement cosobj = parseIndirectObject(input, null);
COSName linearized = COSName.constant("Linearized");
if (cosobj instanceof COSDictionary && ((COSDictionary) cosobj).containsKey(linearized)) {
return result;
}
result = -1;
break;
}
if (next == '%') {
parseComment(input); // this is the binary comment
} else {
break;
}
next = input.read();
}
// reset randomaccess
input.seek(oldOffset);
return result;
}
}