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

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Here is the source code for com.ikon.util.cl.BinaryClassLoader.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.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.Hashtable;
import java.util.jar.Attributes;
import java.util.jar.JarEntry;
import java.util.jar.JarInputStream;

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

public class BinaryClassLoader extends ClassLoader implements MultipleClassLoader {
    private static Logger log = LoggerFactory.getLogger(BinaryClassLoader.class);
    private Hashtable<String, Class<?>> classes = new Hashtable<String, Class<?>>();
    private Hashtable<String, byte[]> resources = new Hashtable<String, byte[]>();
    private String mainClassName = null;

    public BinaryClassLoader(byte[] buf) throws IOException {
        super();
        createCache(buf);

    }

    public BinaryClassLoader(byte[] buf, ClassLoader parent) throws IOException {
        super(parent);
        createCache(buf);
    }

    /**
     * Create internal classes and resources cache
     */
    private void createCache(byte[] buf) throws IOException {
        ByteArrayInputStream bais = null;
        JarInputStream jis = null;
        byte[] buffer = new byte[1024 * 4];

        try {
            bais = new ByteArrayInputStream(buf);
            jis = new JarInputStream(bais);
            Attributes attr = jis.getManifest().getMainAttributes();
            mainClassName = attr != null ? attr.getValue(Attributes.Name.MAIN_CLASS) : null;

            for (JarEntry entry = null; (entry = jis.getNextJarEntry()) != null;) {
                String name = entry.getName();

                if (!entry.isDirectory()) {
                    ByteArrayOutputStream byteStream = new ByteArrayOutputStream();

                    for (int n = 0; -1 != (n = jis.read(buffer));) {
                        byteStream.write(buffer, 0, n);
                    }

                    if (name.endsWith(".class")) {
                        String className = name.substring(0, name.indexOf('.')).replace('/', '.');
                        resources.put(className, byteStream.toByteArray());
                    } else {
                        resources.put(name, byteStream.toByteArray());
                    }

                    byteStream.close();
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            IOUtils.closeQuietly(jis);
            IOUtils.closeQuietly(bais);
        }
    }

    /**
     * Get main class name
     */
    @Override
    public String getMainClassName() throws IOException {
        log.debug("getMainClassName()");
        return mainClassName;
    }

    /**
     * Find class
     */
    @Override
    public Class<?> findClass(String className) {
        log.debug("findClass({})", className);
        Class<?> ret = classes.get(className);

        if (ret != null) {
            return ret;
        }

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

        byte[] classByte = resources.get(className);

        if (classByte != null) {
            ret = defineClass(className, classByte, 0, classByte.length, null);
            classes.put(className, ret);
            resources.remove(className);
            return ret;
        }

        return null;
    }

    /**
     * Get resource input stream
     */
    @Override
    public InputStream getResourceAsStream(String name) {
        log.debug("getResourceAsStream({})", name);
        byte[] bytes = resources.get(name);

        if (bytes != null) {
            return new ByteArrayInputStream(bytes);
        }

        return null;
    }
}