Package org.apache.pdfbox.filter

Class Filter

java.lang.Object

org.apache.pdfbox.filter.Filter

Direct Known Subclasses:

ASCII85Filter, ASCIIHexFilter, CCITTFaxFilter, CryptFilter, DCTFilter, FlateFilter, IdentityFilter, JBIG2Filter, JPXFilter, LZWFilter, RunLengthDecodeFilter

public abstract class Filter
extends java.lang.Object

A filter for stream data.

Field Summary

Fields

Modifier and Type	Field	Description
private static org.apache.commons.logging.Log	LOG
static java.lang.String	SYSPROP_DEFLATELEVEL	Compression Level System Property.

Constructor Summary

Constructors

Modifier	Constructor	Description
protected	Filter()	Constructor.

Method Summary

Modifier and Type	Method	Description
abstract DecodeResult	decode(java.io.InputStream encoded, java.io.OutputStream decoded, COSDictionary parameters, int index)	Decodes data, producing the original non-encoded data.
DecodeResult	decode(java.io.InputStream encoded, java.io.OutputStream decoded, COSDictionary parameters, int index, DecodeOptions options)	Decodes data, with optional DecodeOptions.
static RandomAccessRead	decode(java.io.InputStream encoded, java.util.List<Filter> filterList, COSDictionary parameters, DecodeOptions options, java.util.List<DecodeResult> results)	Decodes data, with optional DecodeOptions.
protected abstract void	encode(java.io.InputStream input, java.io.OutputStream encoded, COSDictionary parameters)
void	encode(java.io.InputStream input, java.io.OutputStream encoded, COSDictionary parameters, int index)	Encodes data.
static javax.imageio.ImageReader	findImageReader(java.lang.String formatName, java.lang.String errorCause)	Finds a suitable image reader for an image format.
static javax.imageio.ImageReader	findRasterReader(java.lang.String formatName, java.lang.String errorCause)	Finds a suitable image raster reader for an image format.
static int	getCompressionLevel()
protected COSDictionary	getDecodeParams(COSDictionary dictionary, int index)

Methods inherited from class java.lang.Object

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

Field Detail

LOG

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

SYSPROP_DEFLATELEVEL

public static final java.lang.String SYSPROP_DEFLATELEVEL

Compression Level System Property. Set this to a value from 0 to 9 to change the zlib deflate compression level used to compress /Flate streams. The default value is -1 which is Deflater.DEFAULT_COMPRESSION. To set maximum compression, use System.setProperty(Filter.SYSPROP_DEFLATELEVEL, "9");

See Also:

Constant Field Values

Constructor Detail

Filter

protected Filter()

Constructor.

Method Detail

decode

public abstract DecodeResult decode(java.io.InputStream encoded,
                                    java.io.OutputStream decoded,
                                    COSDictionary parameters,
                                    int index)
                             throws java.io.IOException

Decodes data, producing the original non-encoded data.

Parameters:

encoded - the encoded byte stream

decoded - the stream where decoded data will be written

parameters - the parameters used for decoding

index - the index to the filter being decoded

Returns:

repaired parameters dictionary, or the original parameters dictionary

Throws:

java.io.IOException - if the stream cannot be decoded

decode

public DecodeResult decode(java.io.InputStream encoded,
                           java.io.OutputStream decoded,
                           COSDictionary parameters,
                           int index,
                           DecodeOptions options)
                    throws java.io.IOException

Decodes data, with optional DecodeOptions. Not all filters support all options, and so callers should check the options' honored flag to test if they were applied.

Parameters:

encoded - the encoded byte stream

decoded - the stream where decoded data will be written

parameters - the parameters used for decoding

index - the index to the filter being decoded

options - additional options for decoding

Returns:

repaired parameters dictionary, or the original parameters dictionary

Throws:

java.io.IOException - if the stream cannot be decoded

encode

public final void encode(java.io.InputStream input,
                         java.io.OutputStream encoded,
                         COSDictionary parameters,
                         int index)
                  throws java.io.IOException

Encodes data.

Parameters:

input - the byte stream to encode

encoded - the stream where encoded data will be written

parameters - the parameters used for encoding

index - the index to the filter being encoded

Throws:

java.io.IOException - if the stream cannot be encoded

encode

protected abstract void encode(java.io.InputStream input,
                               java.io.OutputStream encoded,
                               COSDictionary parameters)
                        throws java.io.IOException

Throws:

java.io.IOException

getDecodeParams

protected COSDictionary getDecodeParams(COSDictionary dictionary,
                                        int index)

findImageReader

public static final javax.imageio.ImageReader findImageReader(java.lang.String formatName,
                                                              java.lang.String errorCause)
                                                       throws MissingImageReaderException

Finds a suitable image reader for an image format.

Parameters:

formatName - The image format to search for.

errorCause - The probably cause if something goes wrong.

Returns:

The image reader for the format.

Throws:

MissingImageReaderException - if no image reader is found.

findRasterReader

public static final javax.imageio.ImageReader findRasterReader(java.lang.String formatName,
                                                               java.lang.String errorCause)
                                                        throws MissingImageReaderException

Finds a suitable image raster reader for an image format.

Parameters:

formatName - The image format to search for.

errorCause - The probably cause if something goes wrong.

Returns:

The image reader for the format.

Throws:

MissingImageReaderException - if no image reader is found.

getCompressionLevel

public static int getCompressionLevel()

Returns:

the ZIP compression level configured for PDFBox

decode

public static RandomAccessRead decode(java.io.InputStream encoded,
                                      java.util.List<Filter> filterList,
                                      COSDictionary parameters,
                                      DecodeOptions options,
                                      java.util.List<DecodeResult> results)
                               throws java.io.IOException

Decodes data, with optional DecodeOptions. Not all filters support all options, and so callers should check the options' honored flag to test if they were applied.

Parameters:

encoded - the input stream holding the encoded data

filterList - list of filters to be used for decoding

parameters - the parameters used for decoding

options - additional options for decoding

results - list of optional decoding results for each filter

Returns:

the decoded stream data

Throws:

java.io.IOException - if the stream cannot be decoded

java.lang.IllegalArgumentException - if filterList is empty