/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
/*
* XRFFLoader.java
* Copyright (C) 2006 University of Waikato, Hamilton, New Zealand
*
*/
package weka.core.converters;
import weka.core.Instance;
import weka.core.Instances;
import weka.core.RevisionUtils;
import weka.core.xml.XMLInstances;
import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.URL;
import java.util.zip.GZIPInputStream;
/**
<!-- globalinfo-start -->
* Reads a source that is in the XML version of the ARFF format. It automatically decompresses the data if the extension is '.xrff.gz'.
* <p/>
<!-- globalinfo-end -->
*
* @author FracPete (fracpete at waikato dot ac dot nz)
* @version $Revision: 1.4 $
* @see Loader
*/
public class XRFFLoader
extends AbstractFileLoader
implements BatchConverter, URLSourcedLoader {
/** for serialization */
private static final long serialVersionUID = 3764533621135196582L;
/** the file extension */
public static String FILE_EXTENSION = XMLInstances.FILE_EXTENSION;
/** the extension for compressed files */
public static String FILE_EXTENSION_COMPRESSED = FILE_EXTENSION + ".gz";
/** the url */
protected String m_URL = "http://";
/** The reader for the source file. */
protected transient Reader m_sourceReader = null;
/** the loaded XML document */
protected XMLInstances m_XMLInstances;
/**
* Returns a string describing this Loader
*
* @return a description of the Loader suitable for
* displaying in the explorer/experimenter gui
*/
public String globalInfo() {
return
"Reads a source that is in the XML version of the ARFF format. "
+ "It automatically decompresses the data if the extension is '"
+ FILE_EXTENSION_COMPRESSED + "'.";
}
/**
* Get the file extension used for libsvm files
*
* @return the file extension
*/
public String getFileExtension() {
return FILE_EXTENSION;
}
/**
* Gets all the file extensions used for this type of file
*
* @return the file extensions
*/
public String[] getFileExtensions() {
return new String[]{FILE_EXTENSION, FILE_EXTENSION_COMPRESSED};
}
/**
* Returns a description of the file type.
*
* @return a short file description
*/
public String getFileDescription() {
return "XRFF data files";
}
/**
* Resets the Loader ready to read a new data set
*
* @throws IOException if something goes wrong
*/
public void reset() throws IOException {
m_structure = null;
m_XMLInstances = null;
setRetrieval(NONE);
if ((m_File != null) && (new File(m_File)).isFile()) {
setFile(new File(m_File));
}
else if ((m_URL != null) && !m_URL.equals("http://")) {
setURL(m_URL);
}
}
/**
* Resets the Loader object and sets the source of the data set to be
* the supplied File object.
*
* @param file the source file.
* @throws IOException if an error occurs
*/
public void setSource(File file) throws IOException {
m_structure = null;
m_XMLInstances = null;
setRetrieval(NONE);
if (file == null)
throw new IOException("Source file object is null!");
try {
if (file.getName().endsWith(FILE_EXTENSION_COMPRESSED))
setSource(new GZIPInputStream(new FileInputStream(file)));
else
setSource(new FileInputStream(file));
}
catch (FileNotFoundException ex) {
throw new IOException("File not found");
}
m_sourceFile = file;
m_File = file.getAbsolutePath();
}
/**
* Resets the Loader object and sets the source of the data set to be
* the supplied url.
*
* @param url the source url.
* @throws IOException if an error occurs
*/
public void setSource(URL url) throws IOException {
m_structure = null;
m_XMLInstances = null;
setRetrieval(NONE);
setSource(url.openStream());
m_URL = url.toString();
}
/**
* Set the url to load from
*
* @param url the url to load from
* @throws IOException if the url can't be set.
*/
public void setURL(String url) throws IOException {
m_URL = url;
setSource(new URL(url));
}
/**
* Return the current url
*
* @return the current url
*/
public String retrieveURL() {
return m_URL;
}
/**
* Resets the Loader object and sets the source of the data set to be
* the supplied InputStream.
*
* @param in the source InputStream.
* @throws IOException if initialization of reader fails.
*/
public void setSource(InputStream in) throws IOException {
m_File = (new File(System.getProperty("user.dir"))).getAbsolutePath();
m_URL = "http://";
m_sourceReader = new BufferedReader(new InputStreamReader(in));
}
/**
* Determines and returns (if possible) the structure (internally the
* header) of the data set as an empty set of instances.
*
* @return the structure of the data set as an empty set
* of Instances
* @throws IOException if an error occurs
*/
public Instances getStructure() throws IOException {
if (m_sourceReader == null)
throw new IOException("No source has been specified");
if (m_structure == null) {
try {
m_XMLInstances = new XMLInstances(m_sourceReader);
m_structure = new Instances(m_XMLInstances.getInstances(), 0);
}
catch (IOException ioe) {
// just re-throw it
throw ioe;
}
catch (Exception e) {
throw new RuntimeException(e);
}
}
return new Instances(m_structure, 0);
}
/**
* 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.
*
* @return the structure of the data set as an empty
* set of Instances
* @throws IOException if there is no source or parsing fails
*/
public Instances getDataSet() throws IOException {
if (m_sourceReader == null)
throw new IOException("No source has been specified");
if (getRetrieval() == INCREMENTAL)
throw new IOException("Cannot mix getting Instances in both incremental and batch modes");
setRetrieval(BATCH);
if (m_structure == null)
getStructure();
return m_XMLInstances.getInstances();
}
/**
* XRFFLoader is unable to process a data set incrementally.
*
* @param structure ignored
* @return never returns without throwing an exception
* @throws IOException always. XRFFLoader is unable to process a
* data set incrementally.
*/
public Instance getNextInstance(Instances structure) throws IOException {
throw new IOException("XRFFLoader can't read data sets incrementally.");
}
/**
* Returns the revision string.
*
* @return the revision
*/
public String getRevision() {
return RevisionUtils.extract("$Revision: 1.4 $");
}
/**
* Main method.
*
* @param args should contain the name of an input file.
*/
public static void main(String[] args) {
runFileLoader(new XRFFLoader(), args);
}
}