This class will collect all XRef/trailer objects and creates correct xref/trailer information after all objects are read using startxref and 'Prev' information (unused XRef/trailer objects are discarded). In case of missing startxref or wrong startxref pointer all XRef/trailer objects are used to create xref table / trailer dictionary in order they occur. For each new xref object/XRef stream method nextXrefObj(long, XRefType) must be called with start byte position. All following calls to setXRef(COSObjectKey, long) or setTrailer(COSDictionary) will add the data for this byte position. After all objects are parsed the startxref position must be provided using setStartxref(long). This is used to build the chain of active xref/trailer objects used for creating document trailer and xref table.

Nested and Inner Type Summary

Modifier and Type	Class and Description
private static class	XrefTrailerResolver.XrefTrailerObj A class which represents a xref/trailer object.
public static enum	XrefTrailerResolver.XRefType The XRefType of a trailer.

Modifier and Type	Field and Description
private final Map<Long, XrefTrailerResolver.XrefTrailerObj>	bytePosToXrefMap
private XrefTrailerResolver.XrefTrailerObj	curXrefTrailerObj
private static final Log	LOG Log instance.
private XrefTrailerResolver.XrefTrailerObj	resolvedXrefTrailer

Constructor Summary

Access	Constructor and Description
public	XrefTrailerResolver()

Method Summary

Modifier and Type	Method and Description
public Set<Long>	Returns: set of object numbers referenced for given object stream or `null` if `setStartxref(long)` was not called before so that no resolved xref table exists getContainedObjectNumbers(final int object number of object stream for which contained object numbers should be returned objstmObjNr) Returns object numbers which are referenced as contained in object stream with specified object number.
public COSDictionary	Returns: the current trailer. getCurrentTrailer() Returns the trailer last set by `setTrailer(COSDictionary)`.
public final COSDictionary	Returns: the first trailer or null getFirstTrailer() Returns the first trailer if at least one exists.
public final COSDictionary	Returns: the last trailer ir null getLastTrailer() Returns the last trailer if at least one exists.
public COSDictionary	Returns: the trailer if available getTrailer() Gets the resolved trailer.
public final int	Returns: the count of trailers. getTrailerCount() Returns the count of trailers.
public Map<COSObjectKey, Long>	Returns: the xrefTable if available getXrefTable() Gets the resolved xref table.
public XrefTrailerResolver.XRefType	Returns: the XRefType or null. getXrefType() Returns the XRefTxpe of the resolved trailer.
public void	nextXrefObj(final long the offset to start at startBytePos, XrefTrailerResolver.XRefType the type of the Xref object type) Signals that a new XRef object (table or stream) starts.
protected void	reset() Reset all data so that it can be used to rebuild the trailer.
public void	setStartxref(long starting position of the first XRef startxrefBytePosValue) Sets the byte position of the first XRef (has to be called after very last startxref was read).
public void	setTrailer(COSDictionary the current document trailer dictionary trailer) Adds trailer information for current XRef object.
public void	setXRef(COSObjectKey The objkey, with id and gen numbers objKey, long The byte offset in this file offset) Populate XRef HashMap of current XRef object.

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

bytePosToXrefMap	back to summary
private final Map<Long, XrefTrailerResolver.XrefTrailerObj> bytePosToXrefMap

curXrefTrailerObj	back to summary
private XrefTrailerResolver.XrefTrailerObj curXrefTrailerObj

LOG	back to summary
private static final Log LOG Log instance.

resolvedXrefTrailer	back to summary
private XrefTrailerResolver.XrefTrailerObj resolvedXrefTrailer

Constructor Detail

XrefTrailerResolver	back to summary
public XrefTrailerResolver()

Method Detail

getContainedObjectNumbers back to summary

getContainedObjectNumbers	back to summary
public Set<Long> getContainedObjectNumbers(final int objstmObjNr) Returns object numbers which are referenced as contained in object stream with specified object number. This will scan resolved xref table for all entries having negated stream object number as value. Parameters objstmObjNr:int object number of object stream for which contained object numbers should be returned Returns:Set<Long> set of object numbers referenced for given object stream or `null` if `setStartxref(long)` was not called before so that no resolved xref table exists

public Set<Long> getContainedObjectNumbers(final int objstmObjNr)

Returns object numbers which are referenced as contained in object stream with specified object number. This will scan resolved xref table for all entries having negated stream object number as value.

Parameters

objstmObjNr:int: object number of object stream for which contained object numbers should be returned

Returns:Set<Long>

set of object numbers referenced for given object stream or null if setStartxref(long) was not called before so that no resolved xref table exists

getCurrentTrailer back to summary

getCurrentTrailer	back to summary
public COSDictionary getCurrentTrailer() Returns the trailer last set by `setTrailer(COSDictionary)`. Returns:COSDictionary the current trailer.

public COSDictionary getCurrentTrailer()

Returns the trailer last set by setTrailer(COSDictionary).

Returns:COSDictionary: the current trailer.

getFirstTrailer	back to summary
public final COSDictionary getFirstTrailer() Returns the first trailer if at least one exists. Returns:COSDictionary the first trailer or null

getFirstTrailer

back to summary

public final COSDictionary getFirstTrailer()

Returns the first trailer if at least one exists.

Returns:COSDictionary: the first trailer or null

getLastTrailer	back to summary
public final COSDictionary getLastTrailer() Returns the last trailer if at least one exists. Returns:COSDictionary the last trailer ir null

getLastTrailer

back to summary

public final COSDictionary getLastTrailer()

Returns the last trailer if at least one exists.

Returns:COSDictionary: the last trailer ir null

getTrailer back to summary

getTrailer	back to summary
public COSDictionary getTrailer() Gets the resolved trailer. Might return `null` in case `setStartxref(long)` was not called before. Returns:COSDictionary the trailer if available

public COSDictionary getTrailer()

Gets the resolved trailer. Might return null in case setStartxref(long) was not called before.

Returns:COSDictionary: the trailer if available

getTrailerCount	back to summary
public final int getTrailerCount() Returns the count of trailers. Returns:int the count of trailers.

getTrailerCount

back to summary

public final int getTrailerCount()

Returns the count of trailers.

Returns:int: the count of trailers.

getXrefTable back to summary

getXrefTable	back to summary
public Map<COSObjectKey, Long> getXrefTable() Gets the resolved xref table. Might return `null` in case `setStartxref(long)` was not called before. Returns:Map<COSObjectKey, Long> the xrefTable if available

public Map<COSObjectKey, Long> getXrefTable()

Gets the resolved xref table. Might return null in case setStartxref(long) was not called before.

Returns:Map<COSObjectKey, Long>: the xrefTable if available

getXrefType	back to summary
public XrefTrailerResolver.XRefType getXrefType() Returns the XRefTxpe of the resolved trailer. Returns:XrefTrailerResolver.XRefType the XRefType or null.

getXrefType

back to summary

public XrefTrailerResolver.XRefType getXrefType()

Returns the XRefTxpe of the resolved trailer.

Returns:XrefTrailerResolver.XRefType: the XRefType or null.

nextXrefObj	back to summary
public void nextXrefObj(final long startBytePos, XrefTrailerResolver.XRefType type) Signals that a new XRef object (table or stream) starts. Parameters startBytePos:long the offset to start at type:XrefTrailerResolver.XRefType the type of the Xref object

nextXrefObj

back to summary

public void nextXrefObj(final long startBytePos, XrefTrailerResolver.XRefType type)

Signals that a new XRef object (table or stream) starts.

Parameters

startBytePos:long: the offset to start at
type:XrefTrailerResolver.XRefType: the type of the Xref object

reset	back to summary
protected void reset() Reset all data so that it can be used to rebuild the trailer.

setStartxref	back to summary
public void setStartxref(long startxrefBytePosValue) Sets the byte position of the first XRef (has to be called after very last startxref was read). This is used to resolve chain of active XRef/trailer. In case startxref position is not found we output a warning and use all XRef/trailer objects combined in byte position order. Thus for incomplete PDF documents with missing startxref one could call this method with parameter value -1. Parameters startxrefBytePosValue:long starting position of the first XRef

setStartxref

back to summary

public void setStartxref(long startxrefBytePosValue)

Sets the byte position of the first XRef (has to be called after very last startxref was read). This is used to resolve chain of active XRef/trailer. In case startxref position is not found we output a warning and use all XRef/trailer objects combined in byte position order. Thus for incomplete PDF documents with missing startxref one could call this method with parameter value -1.

Parameters

startxrefBytePosValue:long: starting position of the first XRef

setTrailer	back to summary
public void setTrailer(COSDictionary trailer) Adds trailer information for current XRef object. Parameters trailer:COSDictionary the current document trailer dictionary

setTrailer

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public void setTrailer(COSDictionary trailer)

Adds trailer information for current XRef object.

Parameters

trailer:COSDictionary: the current document trailer dictionary

setXRef	back to summary
public void setXRef(COSObjectKey objKey, long offset) Populate XRef HashMap of current XRef object. Will add an Xreftable entry that maps ObjectKeys to byte offsets in the file. Parameters objKey:COSObjectKey The objkey, with id and gen numbers offset:long The byte offset in this file

setXRef

back to summary

public void setXRef(COSObjectKey objKey, long offset)

Populate XRef HashMap of current XRef object. Will add an Xreftable entry that maps ObjectKeys to byte offsets in the file.

Parameters

objKey:COSObjectKey: The objkey, with id and gen numbers
offset:long: The byte offset in this file

org.apache.pdfbox.pdfparser back to summary

private Class XrefTrailerResolver.XrefTrailerObj

Class Inheritance

extends Object

java.lang.Object
org.apache.pdfbox.pdfparser.XrefTrailerResolver.XrefTrailerObj

A class which represents a xref/trailer object.

Field Summary

Modifier and Type	Field and Description
protected COSDictionary	trailer
private final Map<COSObjectKey, Long>	xrefTable
private XrefTrailerResolver.XRefType	xrefType

Constructor Summary

Access	Constructor and Description
private	XrefTrailerObj() Default constructor.

Method Summary

Modifier and Type	Method and Description
public void	reset()

Inherited from java.lang.Object:: clone equals finalize getClass hashCode notify notifyAll toString wait wait wait

Field Detail

trailer	back to summary
protected COSDictionary trailer

xrefTable	back to summary
private final Map<COSObjectKey, Long> xrefTable

xrefType	back to summary
private XrefTrailerResolver.XRefType xrefType

Constructor Detail

XrefTrailerObj	back to summary
private XrefTrailerObj() Default constructor.

Method Detail

reset	back to summary
public void reset()

org.apache.pdfbox.pdfparser back to summary

public final Enum XrefTrailerResolver.XRefType

Class Inheritance

extends Enum<XrefTrailerResolver.XRefType>

java.lang.Object
java.lang.Enum
org.apache.pdfbox.pdfparser.XrefTrailerResolver.XRefType

The XRefType of a trailer.

Field Summary

Modifier and Type	Field and Description
public static final XrefTrailerResolver.XRefType	STREAM XRef stream type.
public static final XrefTrailerResolver.XRefType	TABLE XRef table type.

Constructor Summary

Access	Constructor and Description
private	XRefType()

Method Summary

Modifier and Type	Method and Description
public static XrefTrailerResolver.XRefType	valueOf(String name)
public static XrefTrailerResolver.XRefType[]	values()

Inherited from java.lang.Enum:: clone compareTo describeConstable equals finalize getDeclaringClass hashCode name ordinal toString valueOf

Field Detail

STREAM	back to summary
public static final XrefTrailerResolver.XRefType STREAM XRef stream type.

TABLE	back to summary
public static final XrefTrailerResolver.XRefType TABLE XRef table type.

Constructor Detail

XRefType	back to summary
private XRefType()

Method Detail

valueOf	back to summary
public static XrefTrailerResolver.XRefType valueOf(String name)

values	back to summary
public static XrefTrailerResolver.XRefType[] values()

public Class XrefTrailerResolver

Nested and Inner Type Summary

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

private Class XrefTrailerResolver.XrefTrailerObj

Field Summary

Constructor Summary

Method Summary

Field Detail

Constructor Detail

Method Detail

public final Enum XrefTrailerResolver.XRefType

Field Summary

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Method Summary

Field Detail

Constructor Detail

Method Detail