001    /*
002     * Copyright (C) 2008-2010 by Holger Arndt
003     *
004     * This file is part of the Universal Java Matrix Package (UJMP).
005     * See the NOTICE file distributed with this work for additional
006     * information regarding copyright ownership and licensing.
007     *
008     * UJMP is free software; you can redistribute it and/or modify
009     * it under the terms of the GNU Lesser General Public License as
010     * published by the Free Software Foundation; either version 2
011     * of the License, or (at your option) any later version.
012     *
013     * UJMP is distributed in the hope that it will be useful,
014     * but WITHOUT ANY WARRANTY; without even the implied warranty of
015     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
016     * GNU Lesser General Public License for more details.
017     *
018     * You should have received a copy of the GNU Lesser General Public
019     * License along with UJMP; if not, write to the
020     * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
021     * Boston, MA  02110-1301  USA
022     */
023    
024    package org.ujmp.core.util;
025    
026    import java.io.File;
027    import java.io.IOException;
028    import java.lang.reflect.Method;
029    import java.net.URL;
030    import java.net.URLClassLoader;
031    
032    // found at http://forum.java.sun.com/thread.jspa?threadID=300557
033    
034    public class ClassPathHacker {
035    
036            private static final Class<?>[] parameters = new Class[] { URL.class };
037    
038            public static void addFile(String s) throws IOException {
039                    File f = new File(s);
040                    addFile(f);
041            }
042    
043            public static void addFile(File f) throws IOException {
044                    addURL(f.toURI().toURL());
045            }
046    
047            public static void addURL(URL u) throws IOException {
048    
049                    URLClassLoader sysloader = (URLClassLoader) ClassLoader.getSystemClassLoader();
050                    Class<URLClassLoader> sysclass = URLClassLoader.class;
051    
052                    try {
053                            Method method = sysclass.getDeclaredMethod("addURL", parameters);
054                            method.setAccessible(true);
055                            method.invoke(sysloader, new Object[] { u });
056                    } catch (Throwable t) {
057                            t.printStackTrace();
058                            throw new IOException("Error, could not add URL to system classloader");
059                    }
060    
061            }
062    
063    }