Package weka.core.converters

Class JSONLoader

java.lang.Object
weka.core.converters.AbstractLoader
weka.core.converters.AbstractFileLoader
weka.core.converters.JSONLoader
All Implemented Interfaces:
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:

  • Field Details

    • FILE_EXTENSION

      public static String FILE_EXTENSION
      the file extension.

    • FILE_EXTENSION_COMPRESSED

      public static String FILE_EXTENSION_COMPRESSED
      the extension for compressed files.

  • Constructor Details

    • JSONLoader

      public JSONLoader()

  • Method Details

    • globalInfo

      public String globalInfo()
      Returns a string describing this Loader.
      Returns:
      a description of the Loader suitable for displaying in the explorer/experimenter gui

    • getFileExtension

      public String getFileExtension()
      Get the file extension used for JSON files.
      Specified by:
      getFileExtension in interface FileSourcedConverter
      Returns:
      the file extension

    • getFileExtensions

      public 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 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 IOException
      Resets the Loader ready to read a new data set.
      Specified by:
      reset in interface Loader
      Overrides:
      reset in class AbstractFileLoader
      Throws:
      IOException - if something goes wrong

    • setSource

      public void setSource(File file) throws 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:
      IOException - if an error occurs

    • setSource

      public void setSource(URL url) throws IOException
      Resets the Loader object and sets the source of the data set to be the supplied url.
      Parameters:
      url - the source url.
      Throws:
      IOException - if an error occurs

    • setURL

      public void setURL(String url) throws IOException
      Set the url to load from.
      Specified by:
      setURL in interface URLSourcedLoader
      Parameters:
      url - the url to load from
      Throws:
      IOException - if the url can't be set.

    • retrieveURL

      public String retrieveURL()
      Return the current url.
      Specified by:
      retrieveURL in interface URLSourcedLoader
      Returns:
      the current url

    • setSource

      public void setSource(InputStream in) throws 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:
      IOException - if initialization of reader fails.

    • getStructure

      public Instances getStructure() throws 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:
      IOException - if an error occurs

    • getDataSet

      public Instances getDataSet() throws 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:
      IOException - if there is no source or parsing fails

    • getNextInstance

      public Instance getNextInstance(Instances structure) throws 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:
      IOException - always. JSONLoader is unable to process a data set incrementally.

    • getRevision

      public String getRevision()
      Returns the revision string.
      Specified by:
      getRevision in interface RevisionHandler
      Returns:
      the revision

    • main

      public static void main(String[] args)
      Main method.
      Parameters:
      args - should contain the name of an input file.