org.netxilia.api.impl.utils.DynamicClassLoader.java Source code

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Here is the source code for org.netxilia.api.impl.utils.DynamicClassLoader.java

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/*******************************************************************************
 * 
 * Copyright 2010 Alexandru Craciun, and individual contributors as indicated
 * by the @authors tag. 
 * 
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 3 of
 * the License, or (at your option) any later version.
 * 
 * This software 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
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 ******************************************************************************/
package org.netxilia.api.impl.utils;

import java.io.File;
import java.io.FilenameFilter;
import java.io.IOException;
import java.lang.reflect.Method;
import java.net.URL;
import java.net.URLClassLoader;

import org.apache.commons.io.filefilter.SuffixFileFilter;

/**
 * This class add to the classpath the application's main folder.
 * 
 * @author <a href='mailto:ax.craciun@gmail.com'>Alexandru Craciun</a>
 * 
 */
public class DynamicClassLoader {
    private static org.apache.log4j.Logger log = org.apache.log4j.Logger.getLogger(DynamicClassLoader.class);

    private Class<?>[] parameters = new Class[] { URL.class };

    public DynamicClassLoader() {
        try {
            File home = new File(System.getProperty("user.home"), "netxilia");
            if (!home.exists()) {
                if (!home.mkdir()) {
                    log.error("Could not create Netxilia storage directory:" + home);
                    return;
                }
            }
            addFile(home);
            for (File jar : home.listFiles((FilenameFilter) new SuffixFileFilter(".jar"))) {
                addFile(jar);
            }
        } catch (IOException e) {
            log.error("ERROR:" + e);
        }

    }

    public void addFile(String s) throws IOException {
        File f = new File(s);
        addFile(f);
    }

    public void addFile(File f) throws IOException {
        log.info("ADDED:" + f.getAbsolutePath());
        addURL(new URL("file", "", f.getAbsolutePath()));
    }

    public void addURL(URL u) throws IOException {

        URLClassLoader sysloader = (URLClassLoader) ClassLoader.getSystemClassLoader();
        Class<?> sysclass = URLClassLoader.class;

        try {
            Method method = sysclass.getDeclaredMethod("addURL", parameters);
            method.setAccessible(true);
            method.invoke(sysloader, new Object[] { u });
        } catch (Throwable t) {
            t.printStackTrace();
            throw new IOException("Error, could not add URL to system classloader");
        } // end try catch

    }// end method

}