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The Waikato Environment for Knowledge Analysis (WEKA), a machine learning workbench. This is the stable version. Apart from bugfixes, this version does not receive any other updates.

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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 .
 */

/*
 * Groovy.java
 * Copyright (C) 2009-2012 University of Waikato, Hamilton, New Zealand
 */

package weka.core.scripting;

import java.io.File;
import java.io.Serializable;
import java.lang.reflect.Constructor;
import java.lang.reflect.Method;

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

/**
 * A helper class for Groovy.
 * 

* In order to use Groovy, the jar containing all the classes must be present in * the CLASSPATH. This jar is normally found in the embeddable * sub-directory of the Groovy installation. *

* Tested with Groovy 1.5.7. * * @author fracpete (fracpete at waikato dot ac dot nz) * @version $Revision: 10203 $ */ public class Groovy implements Serializable, RevisionHandler { /** for serialization. */ private static final long serialVersionUID = -2628766602043134673L; /** the classname of the Groovy classloader. */ public final static String CLASS_GROOVYCLASSLOADER = "groovy.lang.GroovyClassLoader"; /** whether the Groovy classes are in the Classpath. */ protected static boolean m_Present = false; static { try { Class.forName(CLASS_GROOVYCLASSLOADER); m_Present = true; } catch (Exception e) { m_Present = false; } } /** the classloader. */ protected Object m_ClassLoader; /** * default constructor, tries to instantiate a Groovy classloader. */ public Groovy() { m_ClassLoader = newClassLoader(); } /** * returns the currently used Groovy classloader. * * @return the classloader, can be null */ public Object getClassLoader() { return m_ClassLoader; } /** * executes the specified method on the current interpreter and returns the * result, if any. * * @param methodName the name of the method * @param paramClasses the classes of the parameters * @param paramValues the values of the parameters * @return the return value of the method, if any (in that case null) */ public Object invoke(String methodName, Class[] paramClasses, Object[] paramValues) { Object result; result = null; if (getClassLoader() != null) { result = invoke(getClassLoader(), methodName, paramClasses, paramValues); } return result; } /** * returns whether the Groovy classes are present or not, i.e. whether the * classes are in the classpath or not * * @return whether the Groovy classes are available */ public static boolean isPresent() { return m_Present; } /** * initializes and returns a Groovy Interpreter. * * @return the interpreter or null if Groovy classes not present */ public static Object newClassLoader() { Object result; Class cls; Constructor constr; result = null; if (isPresent()) { try { cls = Class.forName(CLASS_GROOVYCLASSLOADER); constr = cls.getConstructor(new Class[] { ClassLoader.class }); result = constr.newInstance(Groovy.class.getClassLoader()); } catch (Exception e) { e.printStackTrace(); result = null; } } return result; } /** * loads the module and returns a new instance of it as instance of the * provided Java class template. * * @param file the Groovy module file * @param template the template for the returned Java object * @return the Groovy object */ public static Object newInstance(File file, Class template) { Object result; Object interpreter; Class cls; result = null; if (!isPresent()) { return result; } interpreter = newClassLoader(); if (interpreter == null) { return result; } try { cls = (Class) invoke(interpreter, "parseClass", new Class[] { File.class }, new Object[] { file }); result = cls.newInstance(); } catch (Exception e) { e.printStackTrace(); } return result; } /** * executes the specified method and returns the result, if any. * * @param o the object the method should be called from, e.g., a Groovy * Interpreter * @param methodName the name of the method * @param paramClasses the classes of the parameters * @param paramValues the values of the parameters * @return the return value of the method, if any (in that case null) */ public static Object invoke(Object o, String methodName, Class[] paramClasses, Object[] paramValues) { Method m; Object result; result = null; try { m = o.getClass().getMethod(methodName, paramClasses); result = m.invoke(o, paramValues); } catch (Exception e) { e.printStackTrace(); result = null; } return result; } /** * Returns the revision string. * * @return the revision */ @Override public String getRevision() { return RevisionUtils.extract("$Revision: 10203 $"); } /** * If no arguments are given, it just prints the presence of the Groovy * classes, otherwise it expects a Groovy filename to execute. * * @param args commandline arguments */ public static void main(String[] args) { if (args.length == 0) { System.out.println("Groovy present: " + isPresent()); } else { Groovy groovy = new Groovy(); if (groovy.getClassLoader() == null) { System.err.println("Cannot instantiate Groovy ClassLoader!"); } else { Object groovyObject = Groovy.newInstance(new File(args[0]), Object.class); Groovy.invoke(groovyObject, "run", new Class[] {}, new Object[] {}); } } } }





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