Class java.util.zip.Inflater - JDK 5 Documentation v1.1.8, Java 2 SDK 英文文档

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Class java.util.zip.Inflater

java.lang.Object
   |
   +----java.util.zip.Inflater

public class Inflater
extends Object

This class provides support for general purpose decompression using the popular ZLIB compression library. The ZLIB compression library was initially developed as part of the PNG graphics standard and is not protected by patents. It is fully described in RFCs 1950, 1951, and 1952, which can be found at http://info.internet.isi.edu:80/in-notes/rfc/files/ in the files rfc1950.txt (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).

See Also:: Deflater

Inflater(): Creates a new decompressor.
Inflater(boolean): Creates a new decompressor.

end(): Discards unprocessed input and frees internal data.
finalize(): Frees the decompressor when garbage is collected.
finished(): Return true if the end of the compressed data stream has been reached.
getAdler(): Returns the ADLER-32 value of the uncompressed data.
getRemaining(): Returns the total number of bytes remaining in the input buffer.
getTotalIn(): Returns the total number of bytes input so far.
getTotalOut(): Returns the total number of bytes output so far.
inflate(byte[]): Uncompresses bytes into specified buffer.
inflate(byte[], int, int): Uncompresses bytes into specified buffer.
needsDictionary(): Returns true if a preset dictionary is needed for decompression.
needsInput(): Returns true if no data remains in the input buffer.
reset(): Resets inflater so that a new set of input data can be processed.
setDictionary(byte[]): Sets the preset dictionary to the given array of bytes.
setDictionary(byte[], int, int): Sets the preset dictionary to the given array of bytes.
setInput(byte[]): Sets input data for decompression.
setInput(byte[], int, int): Sets input data for decompression.

Inflater

 public Inflater(boolean nowrap)

Creates a new decompressor. If the parameter 'nowrap' is true then the ZLIB header and checksum fields will not be used in order to support the compression format used by both GZIP and PKZIP.

Parameters:: nowrap - if true then support GZIP compatible compression

Inflater

 public Inflater()

Creates a new decompressor.

setInput

 public synchronized void setInput(byte b[],
                                   int off,
                                   int len)

Sets input data for decompression. Should be called whenever needsInput() returns true indicating that more input data is required.

Parameters:: b - the input data bytes; off - the start offset of the input data; len - the length of the input data
See Also:: needsInput

setInput

 public void setInput(byte b[])

Sets input data for decompression. Should be called whenever needsInput() returns true indicating that more input data is required.

Parameters:: b - the input data bytes
See Also:: needsInput

setDictionary

 public native synchronized void setDictionary(byte b[],
                                               int off,
                                               int len)

Sets the preset dictionary to the given array of bytes. Should be called when inflate() returns 0 and needsDictionary() returns true indicating that a preset dictionary is required. The method getAdler() can be used to get the Adler-32 value of the dictionary needed.

Parameters:: b - the dictionary data bytes; off - the start offset of the data; len - the length of the data
See Also:: needsDictionary, getAdler

setDictionary

 public void setDictionary(byte b[])

Parameters:: b - the dictionary data bytes
See Also:: needsDictionary, getAdler

getRemaining

 public synchronized int getRemaining()

Returns the total number of bytes remaining in the input buffer. This can be used to find out what bytes still remain in the input buffer after decompression has finished.

needsInput

 public synchronized boolean needsInput()

Returns true if no data remains in the input buffer. This can be used to determine if #setInput should be called in order to provide more input.

needsDictionary

 public synchronized boolean needsDictionary()

Returns true if a preset dictionary is needed for decompression.

See Also:: InflatesetDictionary

finished

 public synchronized boolean finished()

Return true if the end of the compressed data stream has been reached.

inflate

 public native synchronized int inflate(byte b[],
                                        int off,
                                        int len) throws DataFormatException

Uncompresses bytes into specified buffer. Returns actual number of bytes uncompressed. A return value of 0 indicates that needsInput() or needsDictionary() should be called in order to determine if more input data or a preset dictionary is required. In the later case, getAdler() can be used to get the Adler-32 value of the dictionary required.

Parameters:: b - the buffer for the uncompressed data; off - the start offset of the data; len - the maximum number of uncompressed bytes
Returns:: the actual number of uncompressed bytes
Throws: DataFormatException: if the compressed data format is invalid
See Also:: needsInput, needsDictionary

inflate

 public int inflate(byte b[]) throws DataFormatException

Parameters:: b - the buffer for the uncompressed data
Returns:: the actual number of uncompressed bytes
Throws: DataFormatException: if the compressed data format is invalid
See Also:: needsInput, needsDictionary

getAdler

 public native synchronized int getAdler()

Returns the ADLER-32 value of the uncompressed data.

getTotalIn

 public native synchronized int getTotalIn()

Returns the total number of bytes input so far.

getTotalOut

 public native synchronized int getTotalOut()

Returns the total number of bytes output so far.

reset

 public native synchronized void reset()

Resets inflater so that a new set of input data can be processed.

end

 public native synchronized void end()

Discards unprocessed input and frees internal data.

finalize

 protected void finalize()

Frees the decompressor when garbage is collected.

Overrides:: finalize in class Object

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