Added in API level 1

Inflater

open class Inflater
kotlin.Any
   ↳ java.util.zip.Inflater

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.

This class inflates sequences of ZLIB compressed bytes. The input byte sequence is provided in either byte array or byte buffer, via one of the setInput() methods. The output byte sequence is written to the output byte array or byte buffer passed to the deflate() methods.

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
  }
  

Summary

Public constructors
Inflater(nowrap: Boolean)

Creates a new decompressor.

Creates a new decompressor.

Public methods
open Unit
end()

Closes the decompressor and discards any unprocessed input.

open Boolean

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

open Int

Returns the ADLER-32 value of the uncompressed data.

open Long

Returns the total number of compressed bytes input so far.

open Long

Returns the total number of uncompressed bytes output so far.

open Int

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

open Int

Returns the total number of compressed bytes input so far.

open Int

Returns the total number of uncompressed bytes output so far.

open Int
inflate(output: ByteArray!, off: Int, len: Int)

Uncompresses bytes into specified buffer.

open Int
inflate(output: ByteArray!)

Uncompresses bytes into specified buffer.

open Int
inflate(output: ByteBuffer!)

Uncompresses bytes into specified buffer.

open Boolean

Returns true if a preset dictionary is needed for decompression.

open Boolean

Returns true if no data remains in the input buffer.

open Unit

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

open Unit
setDictionary(dictionary: ByteArray!, off: Int, len: Int)

Sets the preset dictionary to the given array of bytes.

open Unit
setDictionary(dictionary: ByteArray!)

Sets the preset dictionary to the given array of bytes.

open Unit
setDictionary(dictionary: ByteBuffer!)

Sets the preset dictionary to the bytes in the given buffer.

open Unit
setInput(input: ByteArray!, off: Int, len: Int)

Sets input data for decompression.

open Unit

Sets input data for decompression.

open Unit

Sets input data for decompression.

Public constructors

Inflater

Added in API level 1
Inflater(nowrap: Boolean)

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 Boolean: if true then support GZIP compatible compression

Inflater

Added in API level 1
Inflater()

Creates a new decompressor.

Public methods

end

Added in API level 1
open fun end(): Unit

Closes the decompressor and discards any unprocessed input. This method should be called when the decompressor is no longer being used. Once this method is called, the behavior of the Inflater object is undefined.

finished

Added in API level 1
open fun finished(): Boolean

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

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

getAdler

Added in API level 1
open fun getAdler(): Int

Returns the ADLER-32 value of the uncompressed data.

Return
Int the ADLER-32 value of the uncompressed data

getBytesRead

Added in API level 1
open fun getBytesRead(): Long

Returns the total number of compressed bytes input so far.

Return
Long the total (non-negative) number of compressed bytes input so far

getBytesWritten

Added in API level 1
open fun getBytesWritten(): Long

Returns the total number of uncompressed bytes output so far.

Return
Long the total (non-negative) number of uncompressed bytes output so far

getRemaining

Added in API level 1
open fun getRemaining(): Int

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.

Return
Int the total number of bytes remaining in the input buffer

getTotalIn

Added in API level 1
open fun getTotalIn(): Int

Returns the total number of compressed bytes input so far.

Since the number of bytes may be greater than Integer.MAX_VALUE, the getBytesRead() method is now the preferred means of obtaining this information.

Return
Int the total number of compressed bytes input so far

getTotalOut

Added in API level 1
open fun getTotalOut(): Int

Returns the total number of uncompressed bytes output so far.

Since the number of bytes may be greater than Integer.MAX_VALUE, the getBytesWritten() method is now the preferred means of obtaining this information.

Return
Int the total number of uncompressed bytes output so far

inflate

Added in API level 1
open fun inflate(
    output: ByteArray!,
    off: Int,
    len: Int
): Int

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.

If the setInput(java.nio.ByteBuffer) method was called to provide a buffer for input, the input buffer's position will be advanced by the number of bytes consumed by this operation, even in the event that a DataFormatException is thrown.

The remaining byte count will be reduced by the number of consumed input bytes. If the setInput(java.nio.ByteBuffer) method was called to provide a buffer for input, the input buffer's position will be advanced the number of consumed bytes.

These byte totals, as well as the total bytes read and the total bytes written values, will be updated even in the event that a DataFormatException is thrown to reflect the amount of data consumed and produced before the exception occurred.

Parameters
output ByteArray!: the buffer for the uncompressed data
off Int: the start offset of the data
len Int: the maximum number of uncompressed bytes
Return
Int the actual number of uncompressed bytes
Exceptions
java.util.zip.DataFormatException if the compressed data format is invalid

inflate

Added in API level 1
open fun inflate(output: ByteArray!): Int

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.

The remaining byte count will be reduced by the number of consumed input bytes. If the setInput(java.nio.ByteBuffer) method was called to provide a buffer for input, the input buffer's position will be advanced the number of consumed bytes.

These byte totals, as well as the total bytes read and the total bytes written values, will be updated even in the event that a DataFormatException is thrown to reflect the amount of data consumed and produced before the exception occurred.

Parameters
output ByteArray!: the buffer for the uncompressed data
Return
Int the actual number of uncompressed bytes
Exceptions
java.util.zip.DataFormatException if the compressed data format is invalid

inflate

Added in API level 35
open fun inflate(output: ByteBuffer!): Int

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.

On success, the position of the given output byte buffer will be advanced by as many bytes as were produced by the operation, which is equal to the number returned by this method. Note that the position of the output buffer will be advanced even in the event that a DataFormatException is thrown.

The remaining byte count will be reduced by the number of consumed input bytes. If the setInput(java.nio.ByteBuffer) method was called to provide a buffer for input, the input buffer's position will be advanced the number of consumed bytes.

These byte totals, as well as the total bytes read and the total bytes written values, will be updated even in the event that a DataFormatException is thrown to reflect the amount of data consumed and produced before the exception occurred.

Parameters
output ByteBuffer!: the buffer for the uncompressed data
Return
Int the actual number of uncompressed bytes
Exceptions
java.util.zip.DataFormatException if the compressed data format is invalid
java.nio.ReadOnlyBufferException if the given output buffer is read-only

needsDictionary

Added in API level 1
open fun needsDictionary(): Boolean

Returns true if a preset dictionary is needed for decompression.

Return
Boolean true if a preset dictionary is needed for decompression

See Also

    needsInput

    Added in API level 1
    open fun needsInput(): Boolean

    Returns true if no data remains in the input buffer. This can be used to determine if one of the setInput() methods should be called in order to provide more input.

    Return
    Boolean true if no data remains in the input buffer

    reset

    Added in API level 1
    open fun reset(): Unit

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

    setDictionary

    Added in API level 1
    open fun setDictionary(
        dictionary: ByteArray!,
        off: Int,
        len: Int
    ): Unit

    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
    dictionary ByteArray!: the dictionary data bytes
    off Int: the start offset of the data
    len Int: the length of the data

    setDictionary

    Added in API level 1
    open fun setDictionary(dictionary: ByteArray!): Unit

    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
    dictionary ByteArray!: the dictionary data bytes

    setDictionary

    Added in API level 35
    open fun setDictionary(dictionary: ByteBuffer!): Unit

    Sets the preset dictionary to the bytes in the given buffer. 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.

    The bytes in given byte buffer will be fully consumed by this method. On return, its position will equal its limit.

    Parameters
    dictionary ByteBuffer!: the dictionary data bytes

    setInput

    Added in API level 1
    open fun setInput(
        input: ByteArray!,
        off: Int,
        len: Int
    ): Unit

    Sets input data for decompression.

    One of the setInput() methods should be called whenever needsInput() returns true indicating that more input data is required.

    Parameters
    input ByteArray!: the input data bytes
    off Int: the start offset of the input data
    len Int: the length of the input data

    setInput

    Added in API level 1
    open fun setInput(input: ByteArray!): Unit

    Sets input data for decompression.

    One of the setInput() methods should be called whenever needsInput() returns true indicating that more input data is required.

    Parameters
    input ByteArray!: the input data bytes

    setInput

    Added in API level 35
    open fun setInput(input: ByteBuffer!): Unit

    Sets input data for decompression.

    One of the setInput() methods should be called whenever needsInput() returns true indicating that more input data is required.

    The given buffer's position will be advanced as inflate operations are performed, up to the buffer's limit. The input buffer may be modified (refilled) between inflate operations; doing so is equivalent to creating a new buffer and setting it with this method.

    Modifying the input buffer's contents, position, or limit concurrently with an inflate operation will result in undefined behavior, which may include incorrect operation results or operation failure.

    Parameters
    input ByteBuffer!: the input data bytes