com.ikon.util.cl.FilesystemClassLoader.java Source code

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Here is the source code for com.ikon.util.cl.FilesystemClassLoader.java

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/**
 * openkm, Open Document Management System (http://www.openkm.com)
 * Copyright (c) 2006-2013 Paco Avila & Josep Llort
 * 
 * No bytes were intentionally harmed during the development of this application.
 * 
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

package com.ikon.util.cl;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.util.jar.Attributes;
import java.util.jar.Manifest;

import org.apache.commons.io.IOUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class FilesystemClassLoader extends ClassLoader implements MultipleClassLoader {
    private static Logger log = LoggerFactory.getLogger(FilesystemClassLoader.class);
    private File file = null;

    public FilesystemClassLoader(File file) throws IOException {
        super();
        this.file = file;

    }

    public FilesystemClassLoader(File file, ClassLoader parent) throws IOException {
        super(parent);
        this.file = file;
    }

    /**
     * Get main class name
     */
    @Override
    public String getMainClassName() throws IOException {
        log.debug("getMainClassName()");
        File mf = new File(file, "META-INF/MANIFEST.MF");
        FileInputStream fis = null;

        try {
            if (mf.exists() && mf.canRead()) {
                fis = new FileInputStream(mf);
                Manifest manif = new Manifest(fis);
                Attributes attr = manif.getMainAttributes();
                return attr != null ? attr.getValue(Attributes.Name.MAIN_CLASS) : null;
            }
        } finally {
            IOUtils.closeQuietly(fis);
        }

        return null;
    }

    /**
     * Find class
     */
    @Override
    public Class<?> findClass(String className) {
        log.info("findClass({})", className);
        String classFile = className.replace('.', '/').concat(".class");
        File fc = new File(file, classFile);
        FileInputStream fis = null;

        // Check for system class
        try {
            return findSystemClass(className);
        } catch (ClassNotFoundException e) {
            // Ignore
        }

        try {
            if (fc.exists() && fc.canRead()) {
                fis = new FileInputStream(fc);
                byte[] classByte = IOUtils.toByteArray(fis);

                if (classByte != null) {
                    return defineClass(className, classByte, 0, classByte.length, null);
                }
            }
        } catch (IOException e) {
            log.error(e.getMessage(), e);
        } finally {
            IOUtils.closeQuietly(fis);
        }

        return null;
    }

    /**
     * Get resource input stream
     */
    @Override
    public InputStream getResourceAsStream(String name) {
        log.debug("getResourceAsStream({})", name);
        File fr = new File(file, name);

        try {
            if (fr.exists() && fr.canRead()) {
                return new FileInputStream(fr);
            }
        } catch (FileNotFoundException e) {
            log.error(e.getMessage(), e);
        }

        return null;
    }
}