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| java.lang.Object
 java.util.zip.Inflater
| Inflater | | public class Inflater (Code) | | 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 the specifications at
the java.util.zip
package description.
The following code fragment demonstrates a trivial compression
and decompression of a string using Deflater and
Inflater.
try {
// Encode a String into bytes
String inputString = "blahblahblah\u20AC\u20AC";
byte[] input = inputString.getBytes("UTF-8");
// Compress the bytes
byte[] output = new byte[100];
Deflater compresser = new Deflater();
compresser.setInput(input);
compresser.finish();
int compressedDataLength = compresser.deflate(output);
// Decompress the bytes
Inflater decompresser = new Inflater();
decompresser.setInput(output, 0, compressedDataLength);
byte[] result = new byte[100];
int resultLength = decompresser.inflate(result);
decompresser.end();
// Decode the bytes into a String
String outputString = new String(result, 0, resultLength, "UTF-8");
} catch(java.io.UnsupportedEncodingException ex) {
// handle
} catch (java.util.zip.DataFormatException ex) {
// handle
}
See Also: Deflater
version:
1.53, 05/05/07
author:
David Connelly |
| Constructor Summary | |
| public | Inflater(boolean nowrap)
Creates a new decompressor. | | public | Inflater()
Creates a new decompressor. |
| Method Summary | |
| public synchronized void | end()
Closes the decompressor and discards any unprocessed input.
This method should be called when the decompressor is no longer
being used, but will also be called automatically by the finalize()
method. | | protected void | finalize()
Closes the decompressor when garbage is collected. | | public synchronized boolean | finished()
Returns true if the end of the compressed data stream has been
reached. | | public synchronized int | getAdler()
Returns the ADLER-32 value of the uncompressed data. | | public synchronized long | getBytesRead()
| | public synchronized long | getBytesWritten()
| | public synchronized int | getRemaining()
Returns the total number of bytes remaining in the input buffer. | | public int | getTotalIn()
Returns the total number of compressed bytes input so far. | | public int | getTotalOut()
Returns the total number of uncompressed bytes output so far. | | public synchronized int | inflate(byte[] b, int off, int len)
Uncompresses bytes into specified buffer. | | public int | inflate(byte[] b)
Uncompresses bytes into specified buffer. | | public synchronized boolean | needsDictionary()
Returns true if a preset dictionary is needed for decompression. | | public synchronized boolean | needsInput()
Returns true if no data remains in the input buffer. | | public synchronized void | reset()
Resets inflater so that a new set of input data can be processed. | | public synchronized void | setDictionary(byte[] b, int off, int len)
Sets the preset dictionary to the given array of bytes. | | public void | setDictionary(byte[] b)
Sets the preset dictionary to the given array of bytes. | | public synchronized void | setInput(byte[] b, int off, int len)
Sets input data for decompression. | | public void | setInput(byte[] b)
Sets input data for decompression. |
| Inflater | | public Inflater(boolean nowrap)(Code) | | Creates a new decompressor. If the parameter 'nowrap' is true then
the ZLIB header and checksum fields will not be used. This provides
compatibility with the compression format used by both GZIP and PKZIP.
Note: When using the 'nowrap' option it is also necessary to provide
an extra "dummy" byte as input. This is required by the ZLIB native
library in order to support certain optimizations.
Parameters:
nowrap - if true then support GZIP compatible compression |
| Inflater | | public Inflater()(Code) | | Creates a new decompressor.
|
| end | | public synchronized void end()(Code) | | Closes the decompressor and discards any unprocessed input.
This method should be called when the decompressor is no longer
being used, but will also be called automatically by the finalize()
method. Once this method is called, the behavior of the Inflater
object is undefined.
|
| finalize | | protected void finalize()(Code) | | Closes the decompressor when garbage is collected.
|
| finished | | public synchronized boolean finished()(Code) | | Returns true if the end of the compressed data stream has been
reached.
true if the end of the compressed data stream has beenreached |
| getAdler | | public synchronized int getAdler()(Code) | | Returns the ADLER-32 value of the uncompressed data.
the ADLER-32 value of the uncompressed data |
| getBytesRead | | public synchronized long getBytesRead()(Code) | | Returns the total number of compressed bytes input so far.
the total (non-negative) number of compressed bytes input so far
since:
1.5 |
| getBytesWritten | | public synchronized long getBytesWritten()(Code) | | Returns the total number of uncompressed bytes output so far.
the total (non-negative) number of uncompressed bytes output so far
since:
1.5 |
| getRemaining | | public synchronized int getRemaining()(Code) | | 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.
the total number of bytes remaining in the input buffer |
| getTotalIn | | public int getTotalIn()(Code) | | Returns the total number of compressed bytes input so far.
Since the number of bytes may be greater than
Integer.MAX_VALUE, the
Inflater.getBytesRead() method is now
the preferred means of obtaining this information.
the total number of compressed bytes input so far |
| getTotalOut | | public int getTotalOut()(Code) | | Returns the total number of uncompressed bytes output so far.
Since the number of bytes may be greater than
Integer.MAX_VALUE, the
Inflater.getBytesWritten() method is now
the preferred means of obtaining this information.
the total number of uncompressed bytes output so far |
| inflate | | public synchronized int inflate(byte[] b, int off, int len) throws DataFormatException(Code) | | 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 latter case, getAdler() can be used to get the Adler-32
value of the dictionary required.
Parameters:
b - the buffer for the uncompressed data
Parameters:
off - the start offset of the data
Parameters:
len - the maximum number of uncompressed bytes the actual number of uncompressed bytes
exception:
DataFormatException - if the compressed data format is invalid
See Also: Inflater.needsInput
See Also: Inflater.needsDictionary |
| inflate | | public int inflate(byte[] b) throws DataFormatException(Code) | | 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 latter case, getAdler() can be used to get the Adler-32
value of the dictionary required.
Parameters:
b - the buffer for the uncompressed data the actual number of uncompressed bytes
exception:
DataFormatException - if the compressed data format is invalid
See Also: Inflater.needsInput
See Also: Inflater.needsDictionary |
| needsDictionary | | public synchronized boolean needsDictionary()(Code) | | Returns true if a preset dictionary is needed for decompression.
true if a preset dictionary is needed for decompression
See Also: Inflater.setDictionary |
| needsInput | | public synchronized boolean needsInput()(Code) | | 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.
true if no data remains in the input buffer |
| reset | | public synchronized void reset()(Code) | | Resets inflater so that a new set of input data can be processed.
|
| setDictionary | | public synchronized void setDictionary(byte[] b, int off, int len)(Code) | | 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
Parameters:
off - the start offset of the data
Parameters:
len - the length of the data
See Also: Inflater.needsDictionary
See Also: Inflater.getAdler |
| setDictionary | | public void setDictionary(byte[] b)(Code) | | 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
See Also: Inflater.needsDictionary
See Also: Inflater.getAdler |
| setInput | | public synchronized void setInput(byte[] b, int off, int len)(Code) | | 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
Parameters:
off - the start offset of the input data
Parameters:
len - the length of the input data
See Also: Inflater.needsInput |
| setInput | | public void setInput(byte[] b)(Code) | | 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: Inflater.needsInput |
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