com.datalogics.PDFL

Class PDFStream

java.lang.Object

com.datalogics.PDFL.PDFObject

com.datalogics.PDFL.PDFStream

public class PDFStream
extends PDFObject

Represents a stream of data within a PDF document. All objects in a PDF document are built from a collection of simpler objects that represent fundamental datatypes like numbers, strings and arrays.

PDFObject and its subclasses allow direct access and manipulation of these simple objects. Some subclasses represent single data elements (e.g. PDFInteger represents a single integer value); other subclasses represent a collection of PDFObjects (e.g. PDFArray is an indexed array of data elements).

A PDFStream represents a stream of unsigned bytes, and may be inserted into any collection object. It includes a dictionary that describes how the data in the stream is encoded and other useful information about the stream. A PDFStream is always an indirect object.

PDFStreams can be encoded using built-in filters. These filters include compression schemes for most popular image formats, and text encoding translators to permit safe transmission of the document over the Internet. The data in a PDFStream will be automatically encoded when it is created; the user can read either the encoded (raw) or decoded (filtered) data.

PDFStreams can be used for any large collection of data that need not be read into memory all at once, including image data, multimedia data or XML markup.

Constructor Summary

Constructors

Constructor and Description
PDFStream(java.io.InputStream stream, Document doc, PDFDict encoding_dict, PDFArray encoding_params) General constructor
PDFStream(java.io.InputStream stream, PDFObject docFromObj, PDFDict encoding_dict, PDFArray encoding_params) General constructor

Method Summary

Modifier and Type	Method and Description
void	delete()
PDFDict	getDict() The encoding dictionary for the stream.
java.io.InputStream	getFilteredStream() The stream data of this object, decoded according to the filter data in its dictionary.
int	getLength() The encoded length of the stream.
java.io.InputStream	getStream(PDFStreamOpenMode mode) The stream data of this object, processed according to the mode
int	getStreamPos() The byte offset of this stream in the PDF file.
java.io.InputStream	getUnfilteredStream() The unfiltered data of this stream object.
void	SetData(java.io.InputStream stream, PDFDict encoding_dict, PDFArray encoding_params) Replace the data in this PDFStream
java.lang.String	toString()

Methods inherited from class com.datalogics.PDFL.PDFObject

clone, clone, clone, clone, clone, compareTo, destroy, enumPDFObjects, equals, getDocument, getGeneration, getID, getIndirect, getPDFHashValue

Methods inherited from class java.lang.Object

getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

PDFStream

public PDFStream(java.io.InputStream stream,
                 Document doc,
                 PDFDict encoding_dict,
                 PDFArray encoding_params)

General constructor

Parameters:

stream - java.io.InputStream which will provide data for this PDFStream

doc - Document object containing this PDFStream

encoding_dict - PDFDict describing properties of this stream, including the encoding

encoding_params - PDFArray describing parameters for encoding this stream

PDFStream

public PDFStream(java.io.InputStream stream,
                 PDFObject docFromObj,
                 PDFDict encoding_dict,
                 PDFArray encoding_params)

General constructor

Parameters:

stream - java.io.InputStream which will provide data for this PDFStream

docFromObj - The new PDFArray will be created in the same document as this object.

encoding_dict - PDFDict describing properties of this stream, including the encoding

encoding_params - PDFArray describing parameters for encoding this stream

Method Detail

delete

public void delete()

Overrides:

delete in class PDFObject

getStream

public java.io.InputStream getStream(PDFStreamOpenMode mode)

The stream data of this object, processed according to the mode

Parameters:

mode - the open mode with which to read this stream

getFilteredStream

public java.io.InputStream getFilteredStream()

The stream data of this object, decoded according to the filter data in its dictionary.

getUnfilteredStream

public java.io.InputStream getUnfilteredStream()

The unfiltered data of this stream object.

SetData

public void SetData(java.io.InputStream stream,
                    PDFDict encoding_dict,
                    PDFArray encoding_params)

Replace the data in this PDFStream

Parameters:

stream - java.io.InputStream which will provide data for this PDFStream

encoding_dict - PDFDict describing properties of this stream, including the encoding

encoding_params - PDFArray describing parameters for encoding this stream

toString

public java.lang.String toString()

Overrides:

toString in class PDFObject

getDict

public PDFDict getDict()

The encoding dictionary for the stream. This includes all required information for decoding the stream.

getLength

public int getLength()

The encoded length of the stream.

getStreamPos

public int getStreamPos()

The byte offset of this stream in the PDF file.