org.grouplens.lenskit.util.io

Enum CompressionMode

java.lang.Object

java.lang.Enum<CompressionMode>

org.grouplens.lenskit.util.io.CompressionMode

All Implemented Interfaces:

Serializable, Comparable<CompressionMode>

public enum CompressionMode
extends Enum<CompressionMode>

Enum Constant Summary

Enum Constants

Enum Constant and Description
AUTO Automatically infer compression from file extension.
GZIP GZip compression.
NONE No compression.
XZ XZ compression.

Method Summary

Modifier and Type	Method and Description
static CompressionMode	autodetect(File file) Auto-detect a compression mode from a file’s name.
static CompressionMode	autodetect(String name) Auto-detect a compression mode from a file name.
String	getCompressorName()
CompressionMode	getEffectiveCompressionMode(String filename) Get the effective compression mode.
static CompressionMode	valueOf(String name) Returns the enum constant of this type with the specified name.
static CompressionMode[]	values() Returns an array containing the constants of this enum type, in the order they are declared.
InputStream	wrapInput(InputStream in) Wrap an input stream in a decompressor.
OutputStream	wrapOutput(OutputStream out) Wrap an output stream in this compression mode.

Methods inherited from class java.lang.Enum

clone, compareTo, equals, finalize, getDeclaringClass, hashCode, name, ordinal, toString, valueOf

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Enum Constant Detail

NONE

public static final CompressionMode NONE

No compression.

GZIP

public static final CompressionMode GZIP

GZip compression.

See Also:

GZIPInputStream, GZIPOutputStream

XZ

public static final CompressionMode XZ

XZ compression.

AUTO

public static final CompressionMode AUTO

Automatically infer compression from file extension.

Method Detail

values

public static CompressionMode[] values()

Returns an array containing the constants of this enum type, in the order they are declared. This method may be used to iterate over the constants as follows:

for (CompressionMode c : CompressionMode.values())
    System.out.println(c);

Returns:

an array containing the constants of this enum type, in the order they are declared

valueOf

public static CompressionMode valueOf(String name)

Returns the enum constant of this type with the specified name. The string must match exactly an identifier used to declare an enum constant in this type. (Extraneous whitespace characters are not permitted.)

Parameters:

name - the name of the enum constant to be returned.

Returns:

the enum constant with the specified name

Throws:

IllegalArgumentException - if this enum type has no constant with the specified name

NullPointerException - if the argument is null

getCompressorName

public String getCompressorName()

getEffectiveCompressionMode

public CompressionMode getEffectiveCompressionMode(String filename)

Get the effective compression mode. For AUTO, this auto-detects the appropriate mode from the file name.

Parameters:

filename - The filename to compress.

Returns:

The compression mode. Will never be AUTO.

wrapOutput

public OutputStream wrapOutput(OutputStream out)
                        throws IOException

Wrap an output stream in this compression mode.

Parameters:

out - The stream to wrap

Returns:

A stream that will write its output, compressed as appropriate, to out.

Throws:

IOException - If there is an error setting up the compressor.

UnsupportedOperationException - if the mode is AUTO (use getEffectiveCompressionMode(String) first).

wrapInput

public InputStream wrapInput(InputStream in)
                      throws IOException

Wrap an input stream in a decompressor.

Parameters:

in - The input stream.

Returns:

An input stream that wraps in and decompresses as appropriate.

Throws:

IOException - If there is an error setting up the decompressor.

UnsupportedOperationException - if the mode is AUTO (use getEffectiveCompressionMode(String) first).

autodetect

public static CompressionMode autodetect(String name)

Auto-detect a compression mode from a file name.

Parameters:

name - The file name.

Returns:

The compression mode. Will never be AUTO.

autodetect

public static CompressionMode autodetect(File file)

Auto-detect a compression mode from a file’s name.

Parameters:

file - The file.

Returns:

The compression mode. Will never be AUTO.