org.bonitasoft.engine.classloader.VirtualClassLoader Maven / Gradle / Ivy

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/**
 * Copyright (C) 2011-2012 BonitaSoft S.A.
 * BonitaSoft, 32 rue Gustave Eiffel - 38000 Grenoble
 * This library 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
 * version 2.1 of the License.
 * This library 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
 * program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
 * Floor, Boston, MA 02110-1301, USA.
 **/
package org.bonitasoft.engine.classloader;

import java.io.InputStream;

/**
 * @author Elias Ricken de Medeiros
 * @author Charles Souillard
 * @author Baptiste Mesta
 * @author Matthieu Chaffotte
 */
public class VirtualClassLoader extends ClassLoader {
    
    /**
     * WARNING!!!!!!
     * The bigger weakness of this class is that it does not override ALL public, package and protected methods of the java.lang.ClassLoader class
     * The risk (already experimented with Groovy integration for example) is that this VirtualClassLoader will be the parent of any other kind of classloader (GroovyClassLoader for example)
     * and thus, all protected/package methods can be called this this "clhid" classloader. If VirtualClassLoader does not override the given method to delegate this to the BonitaClassLoader instance
     * then the delegation model does not work anymore and some classes/resources can't be found. A good implementation should override all methods...
     */
    private BonitaClassLoader classloader;

    protected final String artifactType;

    protected final long artifactId;

    protected VirtualClassLoader(final String artifactType, final long artifactId, final ClassLoader parent) throws ClassLoaderException {
        super(parent);
        this.artifactType = artifactType;
        this.artifactId = artifactId;
    }

    void setClassLoader(final BonitaClassLoader classloader) {
        this.classloader = classloader;
    }

    @Override
    public Class loadClass(final String name) throws ClassNotFoundException {
        if (this.classloader != null) {
           return this.classloader.loadClass(name, false);
        }
        return getParent().loadClass(name);
    }
    
    @Override
    protected synchronized Class loadClass(final String name, final boolean resolve) throws ClassNotFoundException {
        if (this.classloader != null) {
            return this.classloader.loadClass(name, resolve);
         }
         return getParent().loadClass(name);
    }

    @Override
    public synchronized InputStream getResourceAsStream(final String name) {
        if (this.classloader != null) {
            return this.classloader.getResourceAsStream(name);    
        }
        return null;
    }

    public BonitaClassLoader getClassLoader() {
        return this.classloader;
    }

    public void release() {
        if (this.classloader != null) {
            this.classloader.release();
        }
    }
    
    @Override
    public String toString() {
        return super.toString() + ", type=" + this.artifactType + ", id=" + this.artifactId;
    }

}