java.lang.Object
- weka.core.converters.AbstractLoader
- - weka.core.converters.AbstractFileLoader
  - - weka.core.converters.ArffLoader

All Implemented Interfaces:

java.io.Serializable, BatchConverter, FileSourcedConverter, IncrementalConverter, Loader, URLSourcedLoader, EnvironmentHandler, RevisionHandler
```
public class ArffLoader
extends AbstractFileLoader
implements BatchConverter, IncrementalConverter, URLSourcedLoader
```
Reads a source that is in arff (attribute relation file format) format.

Version:

$Revision: 11137 $

Author:

Mark Hall (mhall@cs.waikato.ac.nz), FracPete (fracpete at waikato dot ac dot nz)

See Also:

Loader, Serialized Form

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static class ArffLoader.ArffReader
Reads data from an ARFF file, either in incremental or batch mode.

Field Summary

Fields
Modifier and Type Field Description

static java.lang.String FILE_EXTENSION
the file extension

static java.lang.String FILE_EXTENSION_COMPRESSED
- Fields inherited from interface weka.core.converters.Loader
  BATCH, INCREMENTAL, NONE

Constructor Summary

Constructors
Constructor Description

ArffLoader()

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
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 arff files
`java.lang.String[]`	`getFileExtensions()`	Gets all the file extensions used for this type of file
`Instance`	`getNextInstance(Instances structure)`	Read the data set incrementally---get the next instance in the data set or returns null if there are no more instances to get.
`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 or the same data set again.
`java.io.File`	`retrieveFile()`	get the File specified as the source
`java.lang.String`	`retrieveURL()`	Return the current url
`void`	`setFile(java.io.File file)`	sets the source File
`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, runFileLoader, setEnvironment, setSource, 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
```
- Constructor Detail
  - ArffLoader
```
public ArffLoader()
```
- 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 arff 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 or the same data set again.
    
    Specified by:
    
    reset in interface Loader
    
    Overrides:
    
    reset in class AbstractFileLoader
    
    Throws:
    
    java.io.IOException - if something goes wrong
  - 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
  - retrieveFile
```
public java.io.File retrieveFile()
```
    get the File specified as the source
    
    Specified by:
    
    retrieveFile in interface FileSourcedConverter
    
    Overrides:
    
    retrieveFile in class AbstractFileLoader
    
    Returns:
    
    the source file
  - setFile
```
public void setFile(java.io.File file)
             throws java.io.IOException
```
    sets the source File
    
    Specified by:
    
    setFile in interface FileSourcedConverter
    
    Overrides:
    
    setFile in class AbstractFileLoader
    
    Parameters:
    
    file - the source file
    
    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 - always thrown.
  - 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
```
    Read the data set incrementally---get the next instance in the data set or returns null if there are no more instances to get. If the structure hasn't yet been determined by a call to getStructure then method should do so before returning the next instance in the data set.
    
    Specified by:
    
    getNextInstance in interface Loader
    
    Specified by:
    
    getNextInstance in class AbstractLoader
    
    Parameters:
    
    structure - the dataset header information, will get updated in case of string or relational attributes
    
    Returns:
    
    the next instance in the data set as an Instance object or null if there are no more instances to be read
    
    Throws:
    
    java.io.IOException - if there is an error during parsing
  - 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.

Modifier and Type	Field	Description
`static java.lang.String`	`FILE_EXTENSION`	the file extension
`static java.lang.String`	`FILE_EXTENSION_COMPRESSED`

Class ArffLoader

Nested Class Summary

Field Summary

Fields inherited from interface weka.core.converters.Loader

Constructor Summary

Method Summary

Methods inherited from class weka.core.converters.AbstractFileLoader

Methods inherited from class weka.core.converters.AbstractLoader

Methods inherited from class java.lang.Object

Field Detail

FILE_EXTENSION

FILE_EXTENSION_COMPRESSED

Constructor Detail

ArffLoader

Method Detail

globalInfo

getFileExtension

getFileExtensions

getFileDescription

reset

setSource

retrieveFile

setFile

setURL

retrieveURL

setSource

getStructure

getDataSet

getNextInstance

getRevision

main