java.util.zip
Class Inflater
java.lang.Object
|
+--java.util.zip.Inflater
public class
Inflaterextends
Object Inflater is used to decompress data that has been compressed according
to the "deflate" standard described in rfc1950.
The usage is as following. First you have to set some input with
setInput()
, then inflate() it. If inflate doesn't
inflate any bytes there may be three reasons:
- needsInput() returns true because the input buffer is empty.
You have to provide more input with
setInput()
.
NOTE: needsInput() also returns true when, the stream is finished.
- needsDictionary() returns true, you have to provide a preset
dictionary with
setDictionary()
.
- finished() returns true, the inflater has finished.
Once the first output byte is produced, a dictionary will not be
needed at a later stage.
Since:Author:- John Leuner, Jochen Hoenicke
Inflater
public Inflater()
Creates a new inflater.
Inflater
public Inflater(boolean nowrap)
Creates a new inflater.
Parameters:
end
public void end()
Frees all objects allocated by the inflater. There's no reason
to call this, since you can just rely on garbage collection (even
for the Sun implementation). Exists only for compatibility
with Sun's JDK, where the compressor allocates native memory.
If you call any method (even reset) afterwards the behaviour is
undefined.
finalize
protected void finalize()
Finalizes this object.
finished
public boolean finished()
Returns true, if the inflater has finished. This means, that no
input is needed and no output can be produced.
getAdler
public int getAdler()
Gets the adler checksum. This is either the checksum of all
uncompressed bytes returned by inflate(), or if needsDictionary()
returns true (and thus no output was yet produced) this is the
adler checksum of the expected dictionary.
getRemaining
public int getRemaining()
Gets the number of unprocessed input. Useful, if the end of the
stream is reached and you want to further process the bytes after
the deflate stream.
Returns:
- the number of bytes of the input which were not processed.
getTotalIn
public int getTotalIn()
Gets the total number of processed compressed input bytes.
Returns:
- the total number of bytes of processed input bytes.
getTotalOut
public int getTotalOut()
Gets the total number of output bytes returned by inflate().
Returns:
- the total number of output bytes.
inflate
public int inflate(byte[] buf)
Inflates the compressed stream to the output buffer. If this
returns 0, you should check, whether needsDictionary(),
needsInput() or finished() returns true, to determine why no
further output is produced.
Parameters:
Returns:
- the number of bytes written to the buffer, 0 if no further
output can be produced.
Throws:
inflate
public int inflate(byte[] buf, int off, int len)
Inflates the compressed stream to the output buffer. If this
returns 0, you should check, whether needsDictionary(),
needsInput() or finished() returns true, to determine why no
further output is produced.
Parameters:
Returns:
- the number of bytes written to the buffer, 0 if no further
output can be produced.
Throws:
needsDictionary
public boolean needsDictionary()
Returns true, if a preset dictionary is needed to inflate the input.
needsInput
public boolean needsInput()
Returns true, if the input buffer is empty.
You should then call setInput().
NOTE: This method also returns true when the stream is finished.
reset
public void reset()
Resets the inflater so that a new stream can be decompressed. All
pending input and output will be discarded.
setDictionary
public void setDictionary(byte[] buffer)
Sets the preset dictionary. This should only be called, if
needsDictionary() returns true and it should set the same
dictionary, that was used for deflating. The getAdler()
function returns the checksum of the dictionary needed.
Parameters:
Throws:
setDictionary
public void setDictionary(byte[] buffer, int off, int len)
Sets the preset dictionary. This should only be called, if
needsDictionary() returns true and it should set the same
dictionary, that was used for deflating. The getAdler()
function returns the checksum of the dictionary needed.
Parameters:
Throws:
setInput
public void setInput(byte[] buf)
Sets the input. This should only be called, if needsInput()
returns true.
Parameters:
Throws:
setInput
public void setInput(byte[] buf, int off, int len)
Sets the input. This should only be called, if needsInput()
returns true.
Parameters:
Throws:
setInput()
, then inflate() it. If inflate doesn't inflate any bytes there may be three reasons:setInput()
. NOTE: needsInput() also returns true when, the stream is finished.setDictionary()
.