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The Waikato Environment for Knowledge Analysis (WEKA), a machine learning workbench. This version represents the developer version, the "bleeding edge" of development, you could say. New functionality gets added to this version.
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/*
 *   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 3 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, see .
 */

/*
 * KOML.java
 * Copyright (C) 2004-2012 University of Waikato, Hamilton, New Zealand
 */

package weka.core.xml;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;

import weka.core.RevisionHandler;
import weka.core.RevisionUtils;

/**
 * This class is a helper class for XML serialization using KOML .
 * KOML does not need to be present, since the class-calls are done generically
 * via Reflection.
 * 
 * @author FracPete (fracpete at waikato dot ac dot nz)
 * @version $Revision 1.0$
 */
public class KOML implements RevisionHandler {

  /**
   * indicates whether KOML (Koala Object Markup Language) is present
   */
  protected static boolean m_Present = false;

  /** the extension for KOML files (including '.') */
  public final static String FILE_EXTENSION = ".koml";

  /** check for KOML statically (needs only to be done once) */
  static {
    checkForKOML();
  }

  /**
   * checks whether the KOML is present in the class path
   */
  private static void checkForKOML() {
    try {
      Class.forName("fr.dyade.koala.xml.koml.KOMLSerializer");
      m_Present = true;
    } catch (Exception e) {
      m_Present = false;
    }
  }

  /**
   * returns whether KOML is present or not, i.e. whether the classes are in the
   * classpath or not
   * 
   * @return whether KOML is available
   */
  public static boolean isPresent() {
    return m_Present;
  }

  /**
   * reads the XML-serialized object from the given file
   * 
   * @param filename the file to deserialize the object from
   * @return the deserialized object
   * @throws Exception if something goes wrong while reading from the file
   */
  public static Object read(String filename) throws Exception {
    return read(new FileInputStream(filename));
  }

  /**
   * reads the XML-serialized object from the given file
   * 
   * @param file the file to deserialize the object from
   * @return the deserialized object
   * @throws Exception if something goes wrong while reading from the file
   */
  public static Object read(File file) throws Exception {
    return read(new FileInputStream(file));
  }

  /**
   * reads the XML-serialized object from a stream
   * 
   * @param stream the stream to deserialize the object from
   * @return the deserialized object
   * @throws Exception if something goes wrong while reading from the stream
   */
  public static Object read(InputStream stream) throws Exception {
    Class komlClass;
    Class[] komlClassArgs;
    Object[] komlArgs;
    java.lang.reflect.Constructor constructor;
    Object koml;
    java.lang.reflect.Method methodRead;
    java.lang.reflect.Method methodClose;
    Class[] readArgsClasses;
    Class[] closeArgsClasses;
    Object[] readArgs;
    Object[] closeArgs;
    Object result;

    result = null;

    // get Deserializer
    komlClass = Class.forName("fr.dyade.koala.xml.koml.KOMLDeserializer");
    komlClassArgs = new Class[2];
    komlClassArgs[0] = java.io.InputStream.class;
    komlClassArgs[1] = Boolean.TYPE;
    komlArgs = new Object[2];
    komlArgs[0] = stream;
    komlArgs[1] = new Boolean(false);
    constructor = komlClass.getConstructor(komlClassArgs);
    koml = constructor.newInstance(komlArgs);
    readArgsClasses = new Class[0];
    methodRead = komlClass.getMethod("readObject", readArgsClasses);
    readArgs = new Object[0];
    closeArgsClasses = new Class[0];
    methodClose = komlClass.getMethod("close", closeArgsClasses);
    closeArgs = new Object[0];

    // execute it
    try {
      result = methodRead.invoke(koml, readArgs);
    } catch (Exception e) {
      result = null;
    } finally {
      methodClose.invoke(koml, closeArgs);
    }

    return result;
  }

  /**
   * writes the XML-serialized object to the given file
   * 
   * @param filename the file to serialize the object to
   * @param o the object to write to the file
   * @return whether writing was successful or not
   * @throws Exception if something goes wrong while writing to the file
   */
  public static boolean write(String filename, Object o) throws Exception {
    return write(new FileOutputStream(filename), o);
  }

  /**
   * write the XML-serialized object to the given file
   * 
   * @param file the file to serialize the object to
   * @param o the object to write to the file
   * @return whether writing was successful or not
   * @throws Exception if something goes wrong while writing to the file
   */
  public static boolean write(File file, Object o) throws Exception {
    return write(new FileOutputStream(file), o);
  }

  /**
   * writes the XML-serialized object to a stream
   * 
   * @param stream the stream to serialize the object to
   * @param o the object to write to the stream
   * @return whether writing was successful or not
   * @throws Exception if something goes wrong while writing to the stream
   */
  public static boolean write(OutputStream stream, Object o) throws Exception {
    Class komlClass;
    Class[] komlClassArgs;
    Object[] komlArgs;
    java.lang.reflect.Constructor constructor;
    Object koml;
    java.lang.reflect.Method methodAdd;
    java.lang.reflect.Method methodClose;
    Class[] addArgsClasses;
    Class[] closeArgsClasses;
    Object[] addArgs;
    Object[] closeArgs;
    boolean result;

    result = false;

    // get Deserializer
    komlClass = Class.forName("fr.dyade.koala.xml.koml.KOMLSerializer");
    komlClassArgs = new Class[2];
    komlClassArgs[0] = java.io.OutputStream.class;
    komlClassArgs[1] = Boolean.TYPE;
    komlArgs = new Object[2];
    komlArgs[0] = stream;
    komlArgs[1] = new Boolean(false);
    constructor = komlClass.getConstructor(komlClassArgs);
    koml = constructor.newInstance(komlArgs);
    addArgsClasses = new Class[1];
    addArgsClasses[0] = Object.class;
    methodAdd = komlClass.getMethod("addObject", addArgsClasses);
    addArgs = new Object[1];
    addArgs[0] = o;
    closeArgsClasses = new Class[0];
    methodClose = komlClass.getMethod("close", closeArgsClasses);
    closeArgs = new Object[0];

    // execute it
    try {
      methodAdd.invoke(koml, addArgs);
      result = true;
    } catch (Exception e) {
      result = false;
    } finally {
      methodClose.invoke(koml, closeArgs);
    }

    return result;
  }

  /**
   * Returns the revision string.
   * 
   * @return the revision
   */
  @Override
  public String getRevision() {
    return RevisionUtils.extract("$Revision: 10203 $");
  }
}