Package weka.core.converters

Class JSONLoader

java.lang.Object

weka.core.converters.AbstractLoader

weka.core.converters.AbstractFileLoader

weka.core.converters.JSONLoader

All Implemented Interfaces:

java.io.Serializable, BatchConverter, FileSourcedConverter, Loader, URLSourcedLoader, EnvironmentHandler, RevisionHandler

public class JSONLoader
extends AbstractFileLoader
implements BatchConverter, URLSourcedLoader

Reads a source that is in the JSON format.
It automatically decompresses the data if the extension is '.json.gz'.

For more information, see JSON homepage:
http://www.json.org/

Version:

$Revision: 8034 $

Author:

FracPete (fracpete at waikato dot ac dot nz)

See Also:

Loader, Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from interface weka.core.converters.Loader

Loader.StructureNotReadyException

Field Summary

Fields

Modifier and Type	Field	Description
static java.lang.String	FILE_EXTENSION	the file extension.
static java.lang.String	FILE_EXTENSION_COMPRESSED	the extension for compressed files.

Fields inherited from interface weka.core.converters.Loader

BATCH, INCREMENTAL, NONE

Constructor Summary

Constructors

Constructor	Description
JSONLoader()

Method Summary

Modifier and Type	Method	Description
Instances	getDataSet()	Return the full data set.
java.lang.String	getFileDescription()	Returns a description of the file type.
java.lang.String	getFileExtension()	Get the file extension used for JSON files.
java.lang.String[]	getFileExtensions()	Gets all the file extensions used for this type of file.
Instance	getNextInstance(Instances structure)	JSONLoader is unable to process a data set incrementally.
java.lang.String	getRevision()	Returns the revision string.
Instances	getStructure()	Determines and returns (if possible) the structure (internally the header) of the data set as an empty set of instances.
java.lang.String	globalInfo()	Returns a string describing this Loader.
static void	main(java.lang.String[] args)	Main method.
void	reset()	Resets the Loader ready to read a new data set.
java.lang.String	retrieveURL()	Return the current url.
void	setSource(java.io.File file)	Resets the Loader object and sets the source of the data set to be the supplied File object.
void	setSource(java.io.InputStream in)	Resets the Loader object and sets the source of the data set to be the supplied InputStream.
void	setSource(java.net.URL url)	Resets the Loader object and sets the source of the data set to be the supplied url.
void	setURL(java.lang.String url)	Set the url to load from.

Methods inherited from class weka.core.converters.AbstractFileLoader

getUseRelativePath, retrieveFile, runFileLoader, setEnvironment, setFile, setUseRelativePath, useRelativePathTipText

Methods inherited from class weka.core.converters.AbstractLoader

setRetrieval

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

FILE_EXTENSION

public static java.lang.String FILE_EXTENSION

the file extension.

FILE_EXTENSION_COMPRESSED

public static java.lang.String FILE_EXTENSION_COMPRESSED

the extension for compressed files.

Constructor Detail

JSONLoader

public JSONLoader()

Method Detail

globalInfo

public java.lang.String globalInfo()

Returns a string describing this Loader.

Returns:

a description of the Loader suitable for displaying in the explorer/experimenter gui

getFileExtension

public java.lang.String getFileExtension()

Get the file extension used for JSON files.

Specified by:

getFileExtension in interface FileSourcedConverter

Returns:

the file extension

getFileExtensions

public java.lang.String[] getFileExtensions()

Gets all the file extensions used for this type of file.

Specified by:

getFileExtensions in interface FileSourcedConverter

Returns:

the file extensions

getFileDescription

public java.lang.String getFileDescription()

Returns a description of the file type.

Specified by:

getFileDescription in interface FileSourcedConverter

Returns:

a short file description

reset

public void reset()
           throws java.io.IOException

Resets the Loader ready to read a new data set.

Specified by:

reset in interface Loader

Overrides:

reset in class AbstractFileLoader

Throws:

java.io.IOException - if something goes wrong

setSource

public void setSource(java.io.File file)
               throws java.io.IOException

Resets the Loader object and sets the source of the data set to be the supplied File object.

Specified by:

setSource in interface Loader

Overrides:

setSource in class AbstractFileLoader

Parameters:

file - the source file.

Throws:

java.io.IOException - if an error occurs

setSource

public void setSource(java.net.URL url)
               throws java.io.IOException

Resets the Loader object and sets the source of the data set to be the supplied url.

Parameters:

url - the source url.

Throws:

java.io.IOException - if an error occurs

setURL

public void setURL(java.lang.String url)
            throws java.io.IOException

Set the url to load from.

Specified by:

setURL in interface URLSourcedLoader

Parameters:

url - the url to load from

Throws:

java.io.IOException - if the url can't be set.

retrieveURL

public java.lang.String retrieveURL()

Return the current url.

Specified by:

retrieveURL in interface URLSourcedLoader

Returns:

the current url

setSource

public void setSource(java.io.InputStream in)
               throws java.io.IOException

Resets the Loader object and sets the source of the data set to be the supplied InputStream.

Specified by:

setSource in interface Loader

Overrides:

setSource in class AbstractLoader

Parameters:

in - the source InputStream.

Throws:

java.io.IOException - if initialization of reader fails.

getStructure

public Instances getStructure()
                       throws java.io.IOException

Determines and returns (if possible) the structure (internally the header) of the data set as an empty set of instances.

Specified by:

getStructure in interface Loader

Specified by:

getStructure in class AbstractLoader

Returns:

the structure of the data set as an empty set of Instances

Throws:

java.io.IOException - if an error occurs

getDataSet

public Instances getDataSet()
                     throws java.io.IOException

Return the full data set. If the structure hasn't yet been determined by a call to getStructure then method should do so before processing the rest of the data set.

Specified by:

getDataSet in interface Loader

Specified by:

getDataSet in class AbstractLoader

Returns:

the structure of the data set as an empty set of Instances

Throws:

java.io.IOException - if there is no source or parsing fails

getNextInstance

public Instance getNextInstance(Instances structure)
                         throws java.io.IOException

JSONLoader is unable to process a data set incrementally.

Specified by:

getNextInstance in interface Loader

Specified by:

getNextInstance in class AbstractLoader

Parameters:

structure - ignored

Returns:

never returns without throwing an exception

Throws:

java.io.IOException - always. JSONLoader is unable to process a data set incrementally.

getRevision

public java.lang.String getRevision()

Returns the revision string.

Specified by:

getRevision in interface RevisionHandler

Returns:

the revision

main

public static void main(java.lang.String[] args)

Main method.

Parameters:

args - should contain the name of an input file.