Package org.apache.pdfbox.pdfparser

Class BruteForceParser

java.lang.Object

org.apache.pdfbox.pdfparser.BaseParser

org.apache.pdfbox.pdfparser.COSParser

org.apache.pdfbox.pdfparser.BruteForceParser

All Implemented Interfaces:

ICOSParser

public class BruteForceParser
extends COSParser

Brute force parser to be used as last resort if a malformed pdf can't be read.

Field Summary

Fields

Modifier and Type	Field	Description
private java.util.Map<COSObjectKey,java.lang.Long>	bfSearchCOSObjectKeyOffsets	Contains all found objects of a brute force search.
private boolean	bfSearchTriggered
private static char[]	EOF_MARKER	EOF-marker.
private static org.apache.commons.logging.Log	LOG
private static long	MINIMUM_SEARCH_OFFSET
private static char[]	OBJ_MARKER	obj-marker.
private static char[]	OBJ_STREAM	ObjStream-marker.
private static char[]	TRAILER_MARKER	trailer-marker.
private static char[]	XREF_STREAM
private static char[]	XREF_TABLE

Fields inherited from class org.apache.pdfbox.pdfparser.COSParser

fileLen, initialParseDone, securityHandler, SYSPROP_EOFLOOKUPRANGE, xrefTrailerResolver

Fields inherited from class org.apache.pdfbox.pdfparser.BaseParser

A, ASCII_CR, ASCII_LF, B, D, DEF, document, E, ENDOBJ_STRING, ENDSTREAM_STRING, J, M, MAX_LENGTH_LONG, N, O, R, S, source, STREAM_STRING, T

Constructor Summary

Constructors

Constructor	Description
BruteForceParser(RandomAccessRead source, COSDocument document)	Constructor.

Method Summary

Modifier and Type	Method	Description
private long	bfSearchForLastEOFMarker()	Brute force search for the last EOF marker.
private void	bfSearchForObjects()	Brute force search for every object in the pdf.
private java.util.Map<java.lang.Long,COSObjectKey>	bfSearchForObjStreamOffsets()	Search for all offsets of object streams within the given pdf
protected void	bfSearchForObjStreams(XrefTrailerResolver trailerResolver, SecurityHandler<? extends ProtectionPolicy> securityHandler)	Brute force search for all objects streams of a pdf.
private boolean	bfSearchForTrailer(COSDictionary trailer)	Brute force search for all trailer marker.
protected long	bfSearchForXRef(long xrefOffset)	Search for the offset of the given xref table/stream among those found by a brute force search.
private java.util.List<java.lang.Long>	bfSearchForXRefStreams()	Brute force search for all /XRef entries (streams).
private java.util.List<java.lang.Long>	bfSearchForXRefTables()	Brute force search for all xref entries (tables).
boolean	bfSearchTriggered()	Indicates wether the brute force search for objects was triggered.
private COSObject	compareCOSObjects(COSObject newObject, java.lang.Long newOffset, COSObject currentObject)
private long	findString(char[] string)	Search for the given string.
protected java.util.Map<COSObjectKey,java.lang.Long>	getBFCOSObjectOffsets()	Returns all found objects of a brute force search.
private boolean	isCatalog(COSDictionary dictionary)	Tell if the dictionary is a PDF or FDF catalog.
private boolean	isInfo(COSDictionary dictionary)	Tell if the dictionary is an info dictionary.
protected COSDictionary	rebuildTrailer(XrefTrailerResolver trailerResolver, SecurityHandler<? extends ProtectionPolicy> securityHandler)	Rebuild the trailer dictionary if startxref can't be found.
private boolean	searchForTrailerItems(COSDictionary trailer)	Search for the different parts of the trailer dictionary.
private long	searchNearestValue(java.util.List<java.lang.Long> values, long offset)

Methods inherited from class org.apache.pdfbox.pdfparser.COSParser

checkPages, createRandomAccessReadView, dereferenceCOSObject, getAccessPermission, getEncryption, isLenient, isString, lastIndexOf, parseCOSStream, parseFDFHeader, parseObjectDynamically, parseObjectStreamObject, parsePDFHeader, parseXrefTable, prepareDecryption, resetTrailerResolver, retrieveTrailer, setEOFLookupRange, setLenient

Methods inherited from class org.apache.pdfbox.pdfparser.BaseParser

getObjectKey, isClosing, isClosing, isDigit, isDigit, isEndOfName, isEOF, isEOL, isEOL, isSpace, isSpace, isWhitespace, isWhitespace, parseCOSArray, parseCOSDictionary, parseCOSName, parseCOSString, parseDirObject, readExpectedChar, readExpectedString, readGenerationNumber, readInt, readLine, readLong, readObjectNumber, readString, readString, readStringNumber, skipLinebreak, skipSpaces, skipWhiteSpaces

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

XREF_TABLE

private static final char[] XREF_TABLE

XREF_STREAM

private static final char[] XREF_STREAM

MINIMUM_SEARCH_OFFSET

private static final long MINIMUM_SEARCH_OFFSET

See Also:

Constant Field Values

EOF_MARKER

private static final char[] EOF_MARKER

EOF-marker.

OBJ_MARKER

private static final char[] OBJ_MARKER

obj-marker.

TRAILER_MARKER

private static final char[] TRAILER_MARKER

trailer-marker.

OBJ_STREAM

private static final char[] OBJ_STREAM

ObjStream-marker.

LOG

private static final org.apache.commons.logging.Log LOG

bfSearchCOSObjectKeyOffsets

private final java.util.Map<COSObjectKey,java.lang.Long> bfSearchCOSObjectKeyOffsets

Contains all found objects of a brute force search.

bfSearchTriggered

private boolean bfSearchTriggered

Constructor Detail

BruteForceParser

public BruteForceParser(RandomAccessRead source,
                        COSDocument document)
                 throws java.io.IOException

Constructor. Triggers a brute force search for all objects of the document.

Parameters:

source - input representing the pdf.

document - the corresponding COS document

Throws:

java.io.IOException - if the source data could not be read

Method Detail

bfSearchTriggered

public boolean bfSearchTriggered()

Indicates wether the brute force search for objects was triggered.

Returns:

true if the search was triggered

getBFCOSObjectOffsets

protected java.util.Map<COSObjectKey,java.lang.Long> getBFCOSObjectOffsets()
                                                                          throws java.io.IOException

Returns all found objects of a brute force search.

Returns:

map containing all found objects of a brute force search

Throws:

java.io.IOException - if something went wrong

bfSearchForObjects

private void bfSearchForObjects()
                         throws java.io.IOException

Brute force search for every object in the pdf.

Throws:

java.io.IOException - if something went wrong

bfSearchForXRef

protected long bfSearchForXRef(long xrefOffset)
                        throws java.io.IOException

Search for the offset of the given xref table/stream among those found by a brute force search.

Parameters:

xrefOffset - the given offset to be searched for

Returns:

the offset of the xref entry

Throws:

java.io.IOException - if something went wrong

searchNearestValue

private long searchNearestValue(java.util.List<java.lang.Long> values,
                                long offset)

bfSearchForObjStreams

protected void bfSearchForObjStreams(XrefTrailerResolver trailerResolver,
                                     SecurityHandler<? extends ProtectionPolicy> securityHandler)
                              throws java.io.IOException

Brute force search for all objects streams of a pdf.

Parameters:

trailerResolver - the trailer resolver of the document

securityHandler - security handler to be used to decrypt encrypted documents

Throws:

java.io.IOException - if something went wrong

bfSearchForTrailer

private boolean bfSearchForTrailer(COSDictionary trailer)
                            throws java.io.IOException

Brute force search for all trailer marker.

Parameters:

trailer - dictionary to be used as trailer dictionary

Throws:

java.io.IOException - if something went wrong

searchForTrailerItems

private boolean searchForTrailerItems(COSDictionary trailer)
                               throws java.io.IOException

Search for the different parts of the trailer dictionary.

Parameters:

trailer - dictionary to be used as trailer dictionary

Returns:

true if the root was found, false if not.

Throws:

java.io.IOException - if something went wrong

compareCOSObjects

private COSObject compareCOSObjects(COSObject newObject,
                                    java.lang.Long newOffset,
                                    COSObject currentObject)

bfSearchForLastEOFMarker

private long bfSearchForLastEOFMarker()
                               throws java.io.IOException

Brute force search for the last EOF marker.

Throws:

java.io.IOException - if something went wrong

bfSearchForObjStreamOffsets

private java.util.Map<java.lang.Long,COSObjectKey> bfSearchForObjStreamOffsets()
                                                                              throws java.io.IOException

Search for all offsets of object streams within the given pdf

Returns:

a map of all offsets for object streams

Throws:

java.io.IOException - if something went wrong

bfSearchForXRefTables

private java.util.List<java.lang.Long> bfSearchForXRefTables()
                                                      throws java.io.IOException

Brute force search for all xref entries (tables).

Throws:

java.io.IOException - if something went wrong

bfSearchForXRefStreams

private java.util.List<java.lang.Long> bfSearchForXRefStreams()
                                                       throws java.io.IOException

Brute force search for all /XRef entries (streams).

Throws:

java.io.IOException - if something went wrong

isInfo

private boolean isInfo(COSDictionary dictionary)

Tell if the dictionary is an info dictionary.

Parameters:

dictionary - the dictionary to be checked

Returns:

true if the given dictionary is an info dictionary

isCatalog

private boolean isCatalog(COSDictionary dictionary)

Tell if the dictionary is a PDF or FDF catalog.

Parameters:

dictionary -

Returns:

true if the given dictionary is a root dictionary

findString

private long findString(char[] string)
                 throws java.io.IOException

Search for the given string. The search starts at the current position and returns the start position if the string was found. -1 is returned if there isn't any further occurrence of the given string. After returning the current position is either the end of the string or the end of the input.

Parameters:

string - the string to be searched

Returns:

the start position of the found string

Throws:

java.io.IOException - if something went wrong

rebuildTrailer

protected COSDictionary rebuildTrailer(XrefTrailerResolver trailerResolver,
                                       SecurityHandler<? extends ProtectionPolicy> securityHandler)
                                throws java.io.IOException

Rebuild the trailer dictionary if startxref can't be found.

Parameters:

trailerResolver - the trailer resolver of the document

securityHandler - security handler to be used to decrypt encrypted documents

Returns:

the rebuild trailer dictionary

Throws:

java.io.IOException - if something went wrong