Class PdfStream
- Direct Known Subclasses:
BaseFont.StreamFont
,PdfContents
,PdfEFStream
,PdfFormXObject
,PdfICCBased
,PdfImage
,PdfPattern
,PRStream
PdfStream
is the Pdf stream object.
A stream, like a string, is a sequence of characters. However, an application can read a small portion of a stream at
a time, while a string must be read in its entirety. For this reason, objects with potentially large amounts of data,
such as images and page descriptions, are represented as streams.
A stream consists of a dictionary that
describes a sequence of characters, followed by the keyword stream, followed by zero or more lines of
characters, followed by the keyword endstream.
All streams must be PdfIndirectObject
s. The
stream dictionary must be a direct object. The keyword stream that follows the stream dictionary should be
followed by a carriage return and linefeed or just a linefeed.
Remark: In this version only the
FLATEDECODE-filter is supported.
This object is described in the 'Portable Document Format Reference Manual
version 1.7' section 3.2.7 (page 60-63).
- See Also:
-
Field Summary
FieldsModifier and TypeFieldDescriptionstatic final int
A possible compression level.static final int
A possible compression level.protected boolean
is the stream compressed?protected int
The level of compression.static final int
A possible compression level.(package private) static final byte[]
protected InputStream
protected long
static final int
A possible compression level.protected long
protected PdfIndirectReference
(package private) static final int
(package private) static final byte[]
protected ByteArrayOutputStream
protected PdfWriter
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Constructor Summary
ConstructorsModifierConstructorDescriptionprotected
Constructs aPdfStream
-object.PdfStream
(byte[] bytes) Constructs aPdfStream
-object.PdfStream
(InputStream inputStream, PdfWriter writer) Creates an efficient stream. -
Method Summary
Modifier and TypeMethodDescriptionvoid
Compresses the stream.void
flateCompress
(int compressionLevel) Compresses the stream.long
Gets the raw length of the stream.protected void
superToPdf
(PdfWriter writer, OutputStream os) void
toPdf
(PdfWriter writer, OutputStream os) Writes the PDF representation of thisPdfDictionary
as an array ofbyte
to the givenOutputStream
.toString()
Returns a string representation of thisPdfDictionary
.void
Writes the data content to anOutputStream
.void
Writes the stream length to thePdfWriter
.Methods inherited from class com.lowagie.text.pdf.PdfDictionary
clear, contains, get, getAsArray, getAsBoolean, getAsDict, getAsIndirectObject, getAsName, getAsNumber, getAsStream, getAsString, getDirectObject, getKeys, getKeysAndValues, isCatalog, isFont, isOutlineTree, isPage, isPages, merge, mergeDifferent, put, putAll, putEx, remove, size
Methods inherited from class com.lowagie.text.pdf.PdfObject
canBeInObjStm, getBytes, getIndRef, isArray, isBoolean, isDictionary, isIndirect, isName, isNull, isNumber, isStream, isString, length, setContent, setIndRef, type
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Field Details
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DEFAULT_COMPRESSION
public static final int DEFAULT_COMPRESSIONA possible compression level.- Since:
- 2.1.3
- See Also:
-
NO_COMPRESSION
public static final int NO_COMPRESSIONA possible compression level.- Since:
- 2.1.3
- See Also:
-
BEST_SPEED
public static final int BEST_SPEEDA possible compression level.- Since:
- 2.1.3
- See Also:
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BEST_COMPRESSION
public static final int BEST_COMPRESSIONA possible compression level.- Since:
- 2.1.3
- See Also:
-
STARTSTREAM
static final byte[] STARTSTREAM -
ENDSTREAM
static final byte[] ENDSTREAM -
SIZESTREAM
static final int SIZESTREAM -
compressed
protected boolean compressedis the stream compressed? -
compressionLevel
protected int compressionLevelThe level of compression.- Since:
- 2.1.3
-
streamBytes
-
inputStream
-
ref
-
inputStreamLength
protected long inputStreamLength -
writer
-
rawLength
protected long rawLength
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Constructor Details
-
PdfStream
public PdfStream(byte[] bytes) Constructs aPdfStream
-object.- Parameters:
bytes
- content of the newPdfObject
as an array ofbyte
.
-
PdfStream
Creates an efficient stream. No temporary array is ever created. TheInputStream
is totally consumed but is not closed. The general usage is:InputStream in = ...; PdfStream stream = new PdfStream(in, writer); stream.flateCompress(); writer.addToBody(stream); stream.writeLength(); in.close();
- Parameters:
inputStream
- the data to write to this streamwriter
- thePdfWriter
for this stream
-
PdfStream
protected PdfStream()Constructs aPdfStream
-object.
-
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Method Details
-
writeLength
Writes the stream length to thePdfWriter
.This method must be called and can only be called if the constructor
PdfStream(InputStream, PdfWriter)
is used to create the stream.- Throws:
IOException
- on error- See Also:
-
getRawLength
public long getRawLength()Gets the raw length of the stream.- Returns:
- the raw length of the stream
-
flateCompress
public void flateCompress()Compresses the stream. -
flateCompress
public void flateCompress(int compressionLevel) Compresses the stream.- Parameters:
compressionLevel
- the compression level (0 = best speed, 9 = best compression, -1 is default)- Since:
- 2.1.3
-
superToPdf
- Throws:
IOException
-
toPdf
Description copied from class:PdfDictionary
Writes the PDF representation of thisPdfDictionary
as an array ofbyte
to the givenOutputStream
.- Overrides:
toPdf
in classPdfDictionary
- Parameters:
writer
- for backwards compatibilityos
- theOutputStream
to write the bytes to.- Throws:
IOException
- on error- See Also:
-
writeContent
Writes the data content to anOutputStream
.- Parameters:
os
- the destination to write to- Throws:
IOException
- on error
-
toString
Description copied from class:PdfDictionary
Returns a string representation of thisPdfDictionary
.The string doesn't contain any of the content of this dictionary. Rather the string "dictionary" is returned, possibly followed by the type of this
PdfDictionary
, if set.- Overrides:
toString
in classPdfDictionary
- Returns:
- the string representation of this
PdfDictionary
- See Also:
-