Apache PDFBox 3.0.4 · org.apache.pdfbox.pdfparser.COSParser

Field Summary

Modifier and Type	Field and Description
private AccessPermission	accessPermission
private BruteForceParser	bruteForceParser
private final Map<Long, Map<COSObjectKey, COSBase>>	decompressedObjects Intermediate cache.
private static final int	DEFAULT_TRAIL_BYTECOUNT How many trailing bytes to read for EOF marker.
private PDEncryption	encryption
private static final byte[]	ENDOBJ
private static final byte[]	ENDSTREAM
protected static final char[]	EOF_MARKER EOF-marker.
private static final String	FDF_DEFAULT_VERSION
private static final String	FDF_HEADER
protected long	fileLen file length.
protected boolean	initialParseDone
private boolean	isLenient is parser using auto healing capacity ?
private String	keyAlias
private InputStream	keyStoreInputStream
private static final Log	LOG Hides org.apache.pdfbox.pdfparser.BaseParser.LOG.
private static final long	MINIMUM_SEARCH_OFFSET
protected static final char[]	OBJ_MARKER obj-marker.
private String	password
private static final String	PDF_DEFAULT_VERSION
private static final String	PDF_HEADER
private int	readTrailBytes how many trailing bytes to read for EOF marker.
protected SecurityHandler<? extends ProtectionPolicy>	securityHandler The security handler.
private static final char[]	STARTXREF
private final byte[]	strmBuf
private static final int	STRMBUFLEN
public static final String	SYSPROP_EOFLOOKUPRANGE The range within the %%EOF marker will be searched.
private boolean	trailerWasRebuild
private static final int	X
private static final char[]	XREF_TABLE
protected XrefTrailerResolver	xrefTrailerResolver Collects all Xref/trailer objects and resolves them into single object using startxref reference.

Inherited from 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

Access	Constructor and Description
public	COSParser(RandomAccessRead input representing the pdf. source) Default constructor.
public	COSParser(RandomAccessRead input representing the pdf. source, String password to be used for decryption. password, InputStream key store to be used for decryption when using public key security keyStore, String alias to be used for decryption when using public key security keyAlias) Constructor for encrypted pdfs.
public	COSParser(RandomAccessRead input representing the pdf. source, String password to be used for decryption. password, InputStream key store to be used for decryption when using public key security keyStore, String alias to be used for decryption when using public key security keyAlias, RandomAccessStreamCache.StreamCacheCreateFunction a function to create an instance of the stream cache streamCacheCreateFunction) Constructor for encrypted pdfs.

Method Summary

Modifier and Type	Method and Description
private long	Returns: the fixed offset calculateXRefFixedOffset(long the given offset where to look at objectOffset) Try to find a fixed offset for the given xref table/stream.
protected void	checkPages(COSDictionary the root dictionary of the pdf root) Check if all entries of the pages dictionary are present.
private int	checkPagesDictionary(COSDictionary pagesDict, Set<COSObject> set)
private long	Returns: the revised offset checkXRefOffset(long startXRefOffset) Check if the cross reference table/stream can be found at the current offset.
private void	checkXrefOffsets() Check the XRef table by dereferencing all objects and fixing the offset if necessary.
private boolean	Returns: the revised offset checkXRefStreamOffset(long the expected start offset of the XRef stream startXRefOffset) Check if the cross reference stream can be found at the current offset.
public RandomAccessReadView	createRandomAccessReadView(long start position within the underlying random access read startPosition, long stream length streamLength) Implements org.apache.pdfbox.cos.ICOSParser.createRandomAccessReadView. Creates a random access read view starting at the given position with the given length.
public COSBase	dereferenceCOSObject(COSObject the COSObject which references the COSBase object to be dereferenced. obj) Implements org.apache.pdfbox.cos.ICOSParser.dereferenceCOSObject. Dereference the COSBase object which is referenced by the given COSObject.
private COSObjectKey	Returns: returns the found/fixed object key findObjectKey(COSObjectKey the key of object we are looking for objectKey, long the offset where to look offset, Map<COSObjectKey, Long> a map with with all known xref entries xrefOffset) Check if the given object can be found at the given offset.
protected AccessPermission	Returns: The access permission of document that was parsed. getAccessPermission() This will get the AccessPermission.
private BruteForceParser	getBruteForceParser()
protected PDEncryption	Returns: The encryption dictionary of the document that was parsed. getEncryption() This will get the encryption dictionary.
private COSNumber	getLength(final COSBase lengthBaseObj) Returns length value referred to or defined in given object.
private Long	getObjectOffset(COSObjectKey objKey, boolean requireExistingNotCompressedObj)
private long	Returns: the offset of StartXref getStartxrefOffset() Looks for and parses startxref.
private void	init(RandomAccessStreamCache.StreamCacheCreateFunction streamCacheCreateFunction)
public boolean	Returns: true if parser is lenient isLenient() Return true if parser is lenient.
private boolean	Returns: true if the bytes are in place, false if not isString(byte[] the bytes of the string to look for string) Checks if the given string can be found at the current offset.
protected boolean	Returns: true if the bytes are in place, false if not isString(char[] the bytes of the string to look for string) Checks if the given string can be found at the current offset.
protected int	Returns: start offset of pattern within buffer or `-1` if pattern could not be found lastIndexOf(final char[] pattern to search for pattern, final byte[] buffer to search pattern in buf, final int offset (exclusive) where lookup starts at endOff) Searches last appearance of pattern within buffer.
protected COSStream	Returns: parsed pdf stream. parseCOSStream(COSDictionary dictionary that goes with this stream. dic) This will read a COSStream from the input stream using length attribute within dictionary.
protected boolean	Returns: true if a FDF header was found parseFDFHeader() Parse the header of a fdf.
private COSBase	parseFileObject(Long objOffset, final COSObjectKey objKey)
private boolean	parseHeader(String headerMarker, String defaultVersion)
protected synchronized COSBase	Returns: the parsed object (which is also added to document object) parseObjectDynamically(COSObjectKey key of object to be parsed objKey, boolean if `true` the object to be parsed must be defined in xref (comment: null objects may be missing from xref) and it must not be a compressed object within object stream (this is used to circumvent being stuck in a loop in a malicious PDF) requireExistingNotCompressedObj) Parse the object for the given object key.
protected COSBase	Returns: the parsed object parseObjectStreamObject(long the number of the offset stream objstmObjNr, COSObjectKey the key of the object to be parsed key) Parse the object with the given key from the object stream with the given number.
protected boolean	Returns: true if a PDF header was found parsePDFHeader() Parse the header of a pdf.
private long	Returns: the startxref value or -1 on parsing error parseStartXref() This will parse the startxref section from the stream.
private boolean	Returns: false on parsing error parseTrailer() This will parse the trailer from the stream and add it to the state.
private COSDictionary	Returns: the trailer dictionary parseXref(long start offset of the first table startXRefOffset) Parses cross reference tables.
private long	Returns: value of PREV item in dictionary or `-1` if no such item exists parseXrefObjStream(long objByteOffset, boolean isStandalone) Parses an xref object stream starting with indirect object id.
protected boolean	Returns: false on parsing error parseXrefTable(long the offset to start at startByteOffset) This will parse the xref table from the stream and add it to the state The XrefTable contents are ignored.
protected void	prepareDecryption() Prepare for decryption.
private long	readUntilEndStream(final EndstreamFilterStream stream we write out to. out) This method will read through the current stream object until we find the keyword "endstream" meaning we're at the end of this object.
protected boolean	Returns: true if the xref trailer resolver should be reset resetTrailerResolver() Indicates whether the xref trailer resolver should be reset or not.
protected COSDictionary	Returns: a COSDictionary containing the trailer information retrieveTrailer() Read the trailer information and provide a COSDictionary containing the trailer information.
public void	setEOFLookupRange(int number of trailing bytes byteCount) Sets how many trailing bytes of PDF file are searched for EOF marker and 'startxref' marker.
protected void	setLenient(boolean try to handle malformed PDFs. lenient) Change the parser leniency flag.
private boolean	validateStreamLength(long streamLength)
private boolean	validateXrefOffsets(Map<COSObjectKey, Long> xrefOffset)

Field Detail

accessPermission	back to summary
private AccessPermission accessPermission

bruteForceParser	back to summary
private BruteForceParser bruteForceParser

decompressedObjects	back to summary
private final Map<Long, Map<COSObjectKey, COSBase>> decompressedObjects Intermediate cache. Contains all objects of already read compressed object streams. Objects are removed after dereferencing them.

DEFAULT_TRAIL_BYTECOUNT	back to summary
private static final int DEFAULT_TRAIL_BYTECOUNT How many trailing bytes to read for EOF marker.

encryption	back to summary
private PDEncryption encryption

ENDOBJ	back to summary
private static final byte[] ENDOBJ

ENDSTREAM	back to summary
private static final byte[] ENDSTREAM

EOF_MARKER	back to summary
protected static final char[] EOF_MARKER EOF-marker.

FDF_DEFAULT_VERSION	back to summary
private static final String FDF_DEFAULT_VERSION

FDF_HEADER	back to summary
private static final String FDF_HEADER

fileLen	back to summary
protected long fileLen file length.

initialParseDone	back to summary
protected boolean initialParseDone

isLenient	back to summary
private boolean isLenient is parser using auto healing capacity ?

keyAlias	back to summary
private String keyAlias

keyStoreInputStream	back to summary
private InputStream keyStoreInputStream

LOG	back to summary
private static final Log LOG Hides org.apache.pdfbox.pdfparser.BaseParser.LOG.

MINIMUM_SEARCH_OFFSET	back to summary
private static final long MINIMUM_SEARCH_OFFSET

OBJ_MARKER	back to summary
protected static final char[] OBJ_MARKER obj-marker.

password	back to summary
private String password Annotations @SuppressWarnings:squid:S2068

PDF_DEFAULT_VERSION	back to summary
private static final String PDF_DEFAULT_VERSION

PDF_HEADER	back to summary
private static final String PDF_HEADER

readTrailBytes	back to summary
private int readTrailBytes how many trailing bytes to read for EOF marker.

securityHandler	back to summary
protected SecurityHandler<? extends ProtectionPolicy> securityHandler The security handler.

STARTXREF	back to summary
private static final char[] STARTXREF

strmBuf	back to summary
private final byte[] strmBuf

STRMBUFLEN	back to summary
private static final int STRMBUFLEN

SYSPROP_EOFLOOKUPRANGE	back to summary
public static final String SYSPROP_EOFLOOKUPRANGE The range within the %%EOF marker will be searched. Useful if there are additional characters after %%EOF within the PDF.

trailerWasRebuild	back to summary
private boolean trailerWasRebuild

X	back to summary
private static final int X

XREF_TABLE	back to summary
private static final char[] XREF_TABLE

xrefTrailerResolver	back to summary
protected XrefTrailerResolver xrefTrailerResolver Collects all Xref/trailer objects and resolves them into single object using startxref reference.

Constructor Detail

COSParser	back to summary
public COSParser(RandomAccessRead source) throws IOException Default constructor. Parameters source:RandomAccessRead input representing the pdf. Exceptions IOException: if something went wrong

COSParser

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public COSParser(RandomAccessRead source) throws IOException

Default constructor.

Parameters

source:RandomAccessRead: input representing the pdf.

Exceptions

IOException:: if something went wrong

COSParser	back to summary
public COSParser(RandomAccessRead source, String password, InputStream keyStore, String keyAlias) throws IOException Constructor for encrypted pdfs. Parameters source:RandomAccessRead input representing the pdf. password:String password to be used for decryption. keyStore:InputStream key store to be used for decryption when using public key security keyAlias:String alias to be used for decryption when using public key security Exceptions IOException: if the source data could not be read

COSParser

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public COSParser(RandomAccessRead source, String password, InputStream keyStore, String keyAlias) throws IOException

Constructor for encrypted pdfs.

Parameters

source:RandomAccessRead: input representing the pdf.
password:String: password to be used for decryption.
keyStore:InputStream: key store to be used for decryption when using public key security
keyAlias:String: alias to be used for decryption when using public key security

Exceptions

IOException:: if the source data could not be read

COSParser	back to summary
public COSParser(RandomAccessRead source, String password, InputStream keyStore, String keyAlias, RandomAccessStreamCache.StreamCacheCreateFunction streamCacheCreateFunction) throws IOException Constructor for encrypted pdfs. Parameters source:RandomAccessRead input representing the pdf. password:String password to be used for decryption. keyStore:InputStream key store to be used for decryption when using public key security keyAlias:String alias to be used for decryption when using public key security streamCacheCreateFunction:RandomAccessStreamCache.StreamCacheCreateFunction a function to create an instance of the stream cache Exceptions IOException: if the source data could not be read

COSParser

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public COSParser(RandomAccessRead source, String password, InputStream keyStore, String keyAlias, RandomAccessStreamCache.StreamCacheCreateFunction streamCacheCreateFunction) throws IOException

Constructor for encrypted pdfs.

Parameters

source:RandomAccessRead: input representing the pdf.
password:String: password to be used for decryption.
keyStore:InputStream: key store to be used for decryption when using public key security
keyAlias:String: alias to be used for decryption when using public key security
streamCacheCreateFunction:RandomAccessStreamCache.StreamCacheCreateFunction: a function to create an instance of the stream cache

Exceptions

IOException:: if the source data could not be read

Method Detail

calculateXRefFixedOffset	back to summary
private long calculateXRefFixedOffset(long objectOffset) throws IOException Try to find a fixed offset for the given xref table/stream. Parameters objectOffset:long the given offset where to look at Returns:long the fixed offset Exceptions IOException: if something went wrong

calculateXRefFixedOffset

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private long calculateXRefFixedOffset(long objectOffset) throws IOException

Try to find a fixed offset for the given xref table/stream.

Parameters

objectOffset:long: the given offset where to look at

Returns:long

the fixed offset

Exceptions

IOException:: if something went wrong

checkPages	back to summary
protected void checkPages(COSDictionary root) throws IOException Check if all entries of the pages dictionary are present. Those which can't be dereferenced are removed. Parameters root:COSDictionary the root dictionary of the pdf Exceptions IOException: if the page tree root is null

checkPages

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protected void checkPages(COSDictionary root) throws IOException

Check if all entries of the pages dictionary are present. Those which can't be dereferenced are removed.

Parameters

root:COSDictionary: the root dictionary of the pdf

Exceptions

IOException:: if the page tree root is null

checkPagesDictionary	back to summary
private int checkPagesDictionary(COSDictionary pagesDict, Set<COSObject> set)

checkXRefOffset	back to summary
private long checkXRefOffset(long startXRefOffset) throws IOException Check if the cross reference table/stream can be found at the current offset. Returns:long the revised offset

checkXRefOffset

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private long checkXRefOffset(long startXRefOffset) throws IOException

Check if the cross reference table/stream can be found at the current offset.

Returns:long: the revised offset

checkXrefOffsets	back to summary
private void checkXrefOffsets() throws IOException Check the XRef table by dereferencing all objects and fixing the offset if necessary. Exceptions IOException: if something went wrong.

checkXrefOffsets

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private void checkXrefOffsets() throws IOException

Check the XRef table by dereferencing all objects and fixing the offset if necessary.

Exceptions

IOException:: if something went wrong.

checkXRefStreamOffset	back to summary
private boolean checkXRefStreamOffset(long startXRefOffset) throws IOException Check if the cross reference stream can be found at the current offset. Parameters startXRefOffset:long the expected start offset of the XRef stream Returns:boolean the revised offset Exceptions IOException: if something went wrong

checkXRefStreamOffset

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private boolean checkXRefStreamOffset(long startXRefOffset) throws IOException

Check if the cross reference stream can be found at the current offset.

Parameters

startXRefOffset:long: the expected start offset of the XRef stream

Returns:boolean

the revised offset

Exceptions

IOException:: if something went wrong

createRandomAccessReadView	back to summary
public RandomAccessReadView createRandomAccessReadView(long startPosition, long streamLength) throws IOException Implements org.apache.pdfbox.cos.ICOSParser.createRandomAccessReadView. Doc from org.apache.pdfbox.cos.ICOSParser.createRandomAccessReadView. Creates a random access read view starting at the given position with the given length. Parameters startPosition:long start position within the underlying random access read streamLength:long stream length Returns:RandomAccessReadView the random access read view Annotations @Override Exceptions IOException: if something went wrong when creating the view for the RandomAccessRead

createRandomAccessReadView

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public RandomAccessReadView createRandomAccessReadView(long startPosition, long streamLength) throws IOException

Implements org.apache.pdfbox.cos.ICOSParser.createRandomAccessReadView.

Doc from org.apache.pdfbox.cos.ICOSParser.createRandomAccessReadView.

Creates a random access read view starting at the given position with the given length.

Parameters

startPosition:long: start position within the underlying random access read
streamLength:long: stream length

Returns:RandomAccessReadView

the random access read view

Annotations

@Override

Exceptions

IOException:: if something went wrong when creating the view for the RandomAccessRead

dereferenceCOSObject	back to summary
public COSBase dereferenceCOSObject(COSObject obj) throws IOException Implements org.apache.pdfbox.cos.ICOSParser.dereferenceCOSObject. Doc from org.apache.pdfbox.cos.ICOSParser.dereferenceCOSObject. Dereference the COSBase object which is referenced by the given COSObject. Parameters obj:COSObject the COSObject which references the COSBase object to be dereferenced. Returns:COSBase the referenced object Annotations @Override Exceptions IOException: if something went wrong when dereferencing the COSBase object

dereferenceCOSObject

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public COSBase dereferenceCOSObject(COSObject obj) throws IOException

Implements org.apache.pdfbox.cos.ICOSParser.dereferenceCOSObject.

Doc from org.apache.pdfbox.cos.ICOSParser.dereferenceCOSObject.

Dereference the COSBase object which is referenced by the given COSObject.

Parameters

obj:COSObject: the COSObject which references the COSBase object to be dereferenced.

Returns:COSBase

the referenced object

Annotations

@Override

Exceptions

IOException:: if something went wrong when dereferencing the COSBase object

findObjectKey	back to summary
private COSObjectKey findObjectKey(COSObjectKey objectKey, long offset, Map<COSObjectKey, Long> xrefOffset) throws IOException Check if the given object can be found at the given offset. Returns the provided object key if everything is ok. If the generation number differs it will be fixed and a new object key is returned. Parameters objectKey:COSObjectKey the key of object we are looking for offset:long the offset where to look xrefOffset:Map<COSObjectKey, Long> a map with with all known xref entries Returns:COSObjectKey returns the found/fixed object key Exceptions IOException: if something went wrong

findObjectKey

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private COSObjectKey findObjectKey(COSObjectKey objectKey, long offset, Map<COSObjectKey, Long> xrefOffset) throws IOException

Check if the given object can be found at the given offset. Returns the provided object key if everything is ok. If the generation number differs it will be fixed and a new object key is returned.

Parameters

objectKey:COSObjectKey: the key of object we are looking for
offset:long: the offset where to look
xrefOffset:Map<COSObjectKey, Long>: a map with with all known xref entries

Returns:COSObjectKey

returns the found/fixed object key

Exceptions

IOException:: if something went wrong

getAccessPermission	back to summary
protected AccessPermission getAccessPermission() throws IOException This will get the AccessPermission. The document must be parsed before this is called. Returns:AccessPermission The access permission of document that was parsed. Exceptions IOException: If there is an error getting the document.

getAccessPermission

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protected AccessPermission getAccessPermission() throws IOException

This will get the AccessPermission. The document must be parsed before this is called.

Returns:AccessPermission

The access permission of document that was parsed.

Exceptions

IOException:: If there is an error getting the document.

getBruteForceParser	back to summary
private BruteForceParser getBruteForceParser() throws IOException

getEncryption	back to summary
protected PDEncryption getEncryption() throws IOException This will get the encryption dictionary. The document must be parsed before this is called. Returns:PDEncryption The encryption dictionary of the document that was parsed. Exceptions IOException: If there is an error getting the document.

getEncryption

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protected PDEncryption getEncryption() throws IOException

This will get the encryption dictionary. The document must be parsed before this is called.

Returns:PDEncryption

The encryption dictionary of the document that was parsed.

Exceptions

IOException:: If there is an error getting the document.

getLength	back to summary
private COSNumber getLength(final COSBase lengthBaseObj) throws IOException Returns length value referred to or defined in given object.

getObjectOffset	back to summary
private Long getObjectOffset(COSObjectKey objKey, boolean requireExistingNotCompressedObj) throws IOException

getStartxrefOffset back to summary

private long getStartxrefOffset() throws IOException

Looks for and parses startxref. We first look for last '%%EOF' marker (within last DEFAULT_TRAIL_BYTECOUNT bytes (or range set via setEOFLookupRange(int)) and go back to find startxref.

Returns:long

the offset of StartXref

Exceptions

IOException:: If something went wrong.

init	back to summary
private void init(RandomAccessStreamCache.StreamCacheCreateFunction streamCacheCreateFunction)

isLenient

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public boolean isLenient()

Return true if parser is lenient. Meaning auto healing capacity of the parser are used.

Returns:boolean: true if parser is lenient

isString

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private boolean isString(byte[] string) throws IOException

Checks if the given string can be found at the current offset.

Parameters

string:byte[]: the bytes of the string to look for

Returns:boolean

true if the bytes are in place, false if not

Exceptions

IOException:: if something went wrong

isString

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protected boolean isString(char[] string) throws IOException

Checks if the given string can be found at the current offset.

Parameters

string:char[]: the bytes of the string to look for

Returns:boolean

true if the bytes are in place, false if not

Exceptions

IOException:: if something went wrong

lastIndexOf back to summary

protected int lastIndexOf(final char[] pattern, final byte[] buf, final int endOff)

Searches last appearance of pattern within buffer. Lookup before _lastOff and goes back until 0.

Parameters

pattern:char[]: pattern to search for
buf:byte[]: buffer to search pattern in
endOff:int: offset (exclusive) where lookup starts at

Returns:int

start offset of pattern within buffer or -1 if pattern could not be found

parseCOSStream

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protected COSStream parseCOSStream(COSDictionary dic) throws IOException

This will read a COSStream from the input stream using length attribute within dictionary. If length attribute is a indirect reference it is first resolved to get the stream length. This means we copy stream data without testing for 'endstream' or 'endobj' and thus it is no problem if these keywords occur within stream. We require 'endstream' to be found after stream data is read.

Parameters

dic:COSDictionary: dictionary that goes with this stream.

Returns:COSStream

parsed pdf stream.

Exceptions

IOException:: if an error occurred reading the stream, like problems with reading length attribute, stream does not end with 'endstream' after data read, stream too short etc.

parseFDFHeader

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protected boolean parseFDFHeader() throws IOException

Parse the header of a fdf.

Returns:boolean

true if a FDF header was found

Exceptions

IOException:: if something went wrong

parseFileObject	back to summary
private COSBase parseFileObject(Long objOffset, final COSObjectKey objKey) throws IOException

parseHeader	back to summary
private boolean parseHeader(String headerMarker, String defaultVersion) throws IOException

parseObjectDynamically back to summary

protected synchronized COSBase parseObjectDynamically(COSObjectKey objKey, boolean requireExistingNotCompressedObj) throws IOException

Parse the object for the given object key.

Parameters

objKey:COSObjectKey: key of object to be parsed
requireExistingNotCompressedObj:boolean: if true the object to be parsed must be defined in xref (comment: null objects may be missing from xref) and it must not be a compressed object within object stream (this is used to circumvent being stuck in a loop in a malicious PDF)

Returns:COSBase

the parsed object (which is also added to document object)

Exceptions

IOException:: If an IO error occurs.

parseObjectStreamObject

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protected COSBase parseObjectStreamObject(long objstmObjNr, COSObjectKey key) throws IOException

Parse the object with the given key from the object stream with the given number.

Parameters

objstmObjNr:long: the number of the offset stream
key:COSObjectKey: the key of the object to be parsed

Returns:COSBase

the parsed object

Exceptions

IOException:: if something went wrong when parsing the object

parsePDFHeader

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protected boolean parsePDFHeader() throws IOException

Parse the header of a pdf.

Returns:boolean

true if a PDF header was found

Exceptions

IOException:: if something went wrong

parseStartXref

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private long parseStartXref() throws IOException

This will parse the startxref section from the stream. The startxref value is ignored.

Returns:long

the startxref value or -1 on parsing error

Exceptions

IOException:: If an IO error occurs.

parseTrailer

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private boolean parseTrailer() throws IOException

This will parse the trailer from the stream and add it to the state.

Returns:boolean

false on parsing error

Exceptions

IOException:: If an IO error occurs.

parseXref

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private COSDictionary parseXref(long startXRefOffset) throws IOException

Parses cross reference tables.

Parameters

startXRefOffset:long: start offset of the first table

Returns:COSDictionary

the trailer dictionary

Exceptions

IOException:: if something went wrong

parseXrefObjStream back to summary

private long parseXrefObjStream(long objByteOffset, boolean isStandalone) throws IOException

Parses an xref object stream starting with indirect object id.

Returns:long: value of PREV item in dictionary or -1 if no such item exists

parseXrefTable

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protected boolean parseXrefTable(long startByteOffset) throws IOException

This will parse the xref table from the stream and add it to the state The XrefTable contents are ignored.

Parameters

startByteOffset:long: the offset to start at

Returns:boolean

false on parsing error

Exceptions

IOException:: If an IO error occurs.

prepareDecryption

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protected void prepareDecryption() throws IOException

Prepare for decryption.

Exceptions

IOException:: if something went wrong
InvalidPasswordException:: If the password is incorrect.

readUntilEndStream

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private long readUntilEndStream(final EndstreamFilterStream out) throws IOException

This method will read through the current stream object until we find the keyword "endstream" meaning we're at the end of this object. Some pdf files, however, forget to write some endstream tags and just close off objects with an "endobj" tag so we have to handle this case as well. This method is optimized using buffered IO and reduced number of byte compare operations.

Parameters

out:EndstreamFilterStream: stream we write out to.

Exceptions

IOException:: if something went wrong

resetTrailerResolver

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protected boolean resetTrailerResolver()

Indicates whether the xref trailer resolver should be reset or not. Should be overwritten if the xref trailer resolver is needed after the initial parsing.

Returns:boolean: true if the xref trailer resolver should be reset

retrieveTrailer

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protected COSDictionary retrieveTrailer() throws IOException

Read the trailer information and provide a COSDictionary containing the trailer information.

Returns:COSDictionary

a COSDictionary containing the trailer information

Exceptions

IOException:: if something went wrong

setEOFLookupRange back to summary

public void setEOFLookupRange(int byteCount)

Sets how many trailing bytes of PDF file are searched for EOF marker and 'startxref' marker. If not set we use default value DEFAULT_TRAIL_BYTECOUNT.

We check that new value is at least 16. However for practical use cases this value should not be lower than 1000; even 2000 was found to not be enough in some cases where some trailing garbage like HTML snippets followed the EOF marker.

In case system property SYSPROP_EOFLOOKUPRANGE is defined this value will be set on initialization but can be overwritten later.

Parameters

byteCount:int: number of trailing bytes

setLenient

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protected void setLenient(boolean lenient)

Change the parser leniency flag. This method can only be called before the parsing of the file.

Parameters

lenient:boolean: try to handle malformed PDFs.

validateStreamLength	back to summary
private boolean validateStreamLength(long streamLength) throws IOException

validateXrefOffsets	back to summary
private boolean validateXrefOffsets(Map<COSObjectKey, Long> xrefOffset) throws IOException

public Class COSParser

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail