java.util.zip
Class Inflater

java.lang.Object sample code for java.lang.Object definition code for java.lang.Object 
  extended by java.util.zip.Inflater

public class Inflater
extends Object sample code for java.lang.Object definition code for java.lang.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 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.

 // Encode a String into bytes
 String inputString = "blahblahblah€€";
 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");
 

See Also:
Deflater sample code for java.util.zip.Deflater definition code for java.util.zip.Deflater

Constructor Summary
Inflater sample code for java.util.zip.Inflater.Inflater() definition code for java.util.zip.Inflater.Inflater() ()
          Creates a new decompressor.
Inflater sample code for java.util.zip.Inflater.Inflater(boolean) definition code for java.util.zip.Inflater.Inflater(boolean) (boolean nowrap)
          Creates a new decompressor.
 
Method Summary
 void end sample code for java.util.zip.Inflater.end() definition code for java.util.zip.Inflater.end() ()
          Closes the decompressor and discards any unprocessed input.
protected  void finalize sample code for java.util.zip.Inflater.finalize() definition code for java.util.zip.Inflater.finalize() ()
          Closes the decompressor when garbage is collected.
 boolean finished sample code for java.util.zip.Inflater.finished() definition code for java.util.zip.Inflater.finished() ()
          Returns true if the end of the compressed data stream has been reached.
 int getAdler sample code for java.util.zip.Inflater.getAdler() definition code for java.util.zip.Inflater.getAdler() ()
          Returns the ADLER-32 value of the uncompressed data.
 long getBytesRead sample code for java.util.zip.Inflater.getBytesRead() definition code for java.util.zip.Inflater.getBytesRead() ()
          Returns the total number of compressed bytes input so far.
 long getBytesWritten sample code for java.util.zip.Inflater.getBytesWritten() definition code for java.util.zip.Inflater.getBytesWritten() ()
          Returns the total number of uncompressed bytes output so far.
 int getRemaining sample code for java.util.zip.Inflater.getRemaining() definition code for java.util.zip.Inflater.getRemaining() ()
          Returns the total number of bytes remaining in the input buffer.
 int getTotalIn sample code for java.util.zip.Inflater.getTotalIn() definition code for java.util.zip.Inflater.getTotalIn() ()
          Returns the total number of compressed bytes input so far.
 int getTotalOut sample code for java.util.zip.Inflater.getTotalOut() definition code for java.util.zip.Inflater.getTotalOut() ()
          Returns the total number of uncompressed bytes output so far.
 int inflate sample code for java.util.zip.Inflater.inflate(byte[]) definition code for java.util.zip.Inflater.inflate(byte[]) (byte[] b)
          Uncompresses bytes into specified buffer.
 int inflate sample code for java.util.zip.Inflater.inflate(byte[], int, int) definition code for java.util.zip.Inflater.inflate(byte[], int, int) (byte[] b, int off, int len)
          Uncompresses bytes into specified buffer.
 boolean needsDictionary sample code for java.util.zip.Inflater.needsDictionary() definition code for java.util.zip.Inflater.needsDictionary() ()
          Returns true if a preset dictionary is needed for decompression.
 boolean needsInput sample code for java.util.zip.Inflater.needsInput() definition code for java.util.zip.Inflater.needsInput() ()
          Returns true if no data remains in the input buffer.
 void reset sample code for java.util.zip.Inflater.reset() definition code for java.util.zip.Inflater.reset() ()
          Resets inflater so that a new set of input data can be processed.
 void setDictionary sample code for java.util.zip.Inflater.setDictionary(byte[]) definition code for java.util.zip.Inflater.setDictionary(byte[]) (byte[] b)
          Sets the preset dictionary to the given array of bytes.
 void setDictionary sample code for java.util.zip.Inflater.setDictionary(byte[], int, int) definition code for java.util.zip.Inflater.setDictionary(byte[], int, int) (byte[] b, int off, int len)
          Sets the preset dictionary to the given array of bytes.
 void setInput sample code for java.util.zip.Inflater.setInput(byte[]) definition code for java.util.zip.Inflater.setInput(byte[]) (byte[] b)
          Sets input data for decompression.
 void setInput sample code for java.util.zip.Inflater.setInput(byte[], int, int) definition code for java.util.zip.Inflater.setInput(byte[], int, int) (byte[] b, int off, int len)
          Sets input data for decompression.
 
Methods inherited from class java.lang.Object sample code for java.lang.Object definition code for java.lang.Object
clone sample code for java.lang.Object.clone() definition code for java.lang.Object.clone() , equals sample code for java.lang.Object.equals(java.lang.Object) definition code for java.lang.Object.equals(java.lang.Object) , getClass sample code for java.lang.Object.getClass() definition code for java.lang.Object.getClass() , hashCode sample code for java.lang.Object.hashCode() definition code for java.lang.Object.hashCode() , notify sample code for java.lang.Object.notify() definition code for java.lang.Object.notify() , notifyAll sample code for java.lang.Object.notifyAll() definition code for java.lang.Object.notifyAll() , toString sample code for java.lang.Object.toString() definition code for java.lang.Object.toString() , wait sample code for java.lang.Object.wait() definition code for java.lang.Object.wait() , wait sample code for java.lang.Object.wait(long) definition code for java.lang.Object.wait(long) , wait sample code for java.lang.Object.wait(long, int) definition code for java.lang.Object.wait(long, int)
 

Constructor Detail

Inflater sample code for java.util.zip.Inflater(boolean) definition code for java.util.zip.Inflater(boolean)

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. 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 sample code for java.util.zip.Inflater() definition code for java.util.zip.Inflater()

public Inflater()
Creates a new decompressor.

Method Detail

setInput sample code for java.util.zip.Inflater.setInput(byte[], int, int) definition code for java.util.zip.Inflater.setInput(byte[], int, int)

public 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() sample code for java.util.zip.Inflater.needsInput() definition code for java.util.zip.Inflater.needsInput()

setInput sample code for java.util.zip.Inflater.setInput(byte[]) definition code for java.util.zip.Inflater.setInput(byte[])

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() sample code for java.util.zip.Inflater.needsInput() definition code for java.util.zip.Inflater.needsInput()

setDictionary sample code for java.util.zip.Inflater.setDictionary(byte[], int, int) definition code for java.util.zip.Inflater.setDictionary(byte[], int, int)

public 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() sample code for java.util.zip.Inflater.needsDictionary() definition code for java.util.zip.Inflater.needsDictionary() , getAdler() sample code for java.util.zip.Inflater.getAdler() definition code for java.util.zip.Inflater.getAdler()

setDictionary sample code for java.util.zip.Inflater.setDictionary(byte[]) definition code for java.util.zip.Inflater.setDictionary(byte[])

public void setDictionary(byte[] b)
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:
needsDictionary() sample code for java.util.zip.Inflater.needsDictionary() definition code for java.util.zip.Inflater.needsDictionary() , getAdler() sample code for java.util.zip.Inflater.getAdler() definition code for java.util.zip.Inflater.getAdler()

getRemaining sample code for java.util.zip.Inflater.getRemaining() definition code for java.util.zip.Inflater.getRemaining()

public 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.

Returns:
the total number of bytes remaining in the input buffer

needsInput sample code for java.util.zip.Inflater.needsInput() definition code for java.util.zip.Inflater.needsInput()

public 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.

Returns:
true if no data remains in the input buffer

needsDictionary sample code for java.util.zip.Inflater.needsDictionary() definition code for java.util.zip.Inflater.needsDictionary()

public boolean needsDictionary()
Returns true if a preset dictionary is needed for decompression.

Returns:
true if a preset dictionary is needed for decompression
See Also:
setDictionary(byte[], int, int) sample code for java.util.zip.Inflater.setDictionary(byte[], int, int) definition code for java.util.zip.Inflater.setDictionary(byte[], int, int)

finished sample code for java.util.zip.Inflater.finished() definition code for java.util.zip.Inflater.finished()

public boolean finished()
Returns true if the end of the compressed data stream has been reached.

Returns:
true if the end of the compressed data stream has been reached

inflate sample code for java.util.zip.Inflater.inflate(byte[], int, int) definition code for java.util.zip.Inflater.inflate(byte[], int, int)

public int inflate(byte[] b,
                   int off,
                   int len)
            throws DataFormatException sample code for java.util.zip.DataFormatException definition code for java.util.zip.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 sample code for java.util.zip.DataFormatException definition code for java.util.zip.DataFormatException - if the compressed data format is invalid
See Also:
needsInput() sample code for java.util.zip.Inflater.needsInput() definition code for java.util.zip.Inflater.needsInput() , needsDictionary() sample code for java.util.zip.Inflater.needsDictionary() definition code for java.util.zip.Inflater.needsDictionary()

inflate sample code for java.util.zip.Inflater.inflate(byte[]) definition code for java.util.zip.Inflater.inflate(byte[])

public int inflate(byte[] b)
            throws DataFormatException sample code for java.util.zip.DataFormatException definition code for java.util.zip.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
Returns:
the actual number of uncompressed bytes
Throws:
DataFormatException sample code for java.util.zip.DataFormatException definition code for java.util.zip.DataFormatException - if the compressed data format is invalid
See Also:
needsInput() sample code for java.util.zip.Inflater.needsInput() definition code for java.util.zip.Inflater.needsInput() , needsDictionary() sample code for java.util.zip.Inflater.needsDictionary() definition code for java.util.zip.Inflater.needsDictionary()

getAdler sample code for java.util.zip.Inflater.getAdler() definition code for java.util.zip.Inflater.getAdler()

public int getAdler()
Returns the ADLER-32 value of the uncompressed data.

Returns:
the ADLER-32 value of the uncompressed data

getTotalIn sample code for java.util.zip.Inflater.getTotalIn() definition code for java.util.zip.Inflater.getTotalIn()

public int getTotalIn()
Returns the total number of compressed bytes input so far.

Since the number of bytes may be greater than Integer.MAX_VALUE, the getBytesRead() sample code for java.util.zip.Inflater.getBytesRead() definition code for java.util.zip.Inflater.getBytesRead() method is now the preferred means of obtaining this information.

Returns:
the total number of compressed bytes input so far

getBytesRead sample code for java.util.zip.Inflater.getBytesRead() definition code for java.util.zip.Inflater.getBytesRead()

public long getBytesRead()
Returns the total number of compressed bytes input so far.

Returns:
the total (non-negative) number of compressed bytes input so far

getTotalOut sample code for java.util.zip.Inflater.getTotalOut() definition code for java.util.zip.Inflater.getTotalOut()

public int getTotalOut()
Returns the total number of uncompressed bytes output so far.

Since the number of bytes may be greater than Integer.MAX_VALUE, the getBytesWritten() sample code for java.util.zip.Inflater.getBytesWritten() definition code for java.util.zip.Inflater.getBytesWritten() method is now the preferred means of obtaining this information.

Returns:
the total number of uncompressed bytes output so far

getBytesWritten sample code for java.util.zip.Inflater.getBytesWritten() definition code for java.util.zip.Inflater.getBytesWritten()

public long getBytesWritten()
Returns the total number of uncompressed bytes output so far.

Returns:
the total (non-negative) number of uncompressed bytes output so far

reset sample code for java.util.zip.Inflater.reset() definition code for java.util.zip.Inflater.reset()

public void reset()
Resets inflater so that a new set of input data can be processed.


end sample code for java.util.zip.Inflater.end() definition code for java.util.zip.Inflater.end()

public 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. Once this method is called, the behavior of the Inflater object is undefined.


finalize sample code for java.util.zip.Inflater.finalize() definition code for java.util.zip.Inflater.finalize()

protected void finalize()
Closes the decompressor when garbage is collected.

Overrides:
finalize sample code for java.lang.Object.finalize() definition code for java.lang.Object.finalize() in class Object sample code for java.lang.Object definition code for java.lang.Object