org.radargun.utils.ClassLoadHelper.java Source code

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Here is the source code for org.radargun.utils.ClassLoadHelper.java

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/* 
 * JBoss, Home of Professional Open Source
 * Copyright 2012 Red Hat Inc. and/or its affiliates and other contributors
 * as indicated by the @author tags. All rights reserved.
 * See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU Lesser General Public License, v. 2.1.
 * This program is distributed in the hope that it will be useful, but WITHOUT A
 * 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,
 * v.2.1 along with this distribution; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA  02110-1301, USA.
 */
package org.radargun.utils;

import java.net.URLClassLoader;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.radargun.state.StateBase;

public class ClassLoadHelper {

    private static final Log log = LogFactory.getLog(ClassLoadHelper.class);

    private boolean useSmartClassLoading;
    private Class<?> instantiator;
    private String thisProduct;
    private StateBase state;
    private String prevProductKey;
    private String classLoaderKey;

    public ClassLoadHelper(boolean useSmartClassLoading, Class<?> instantiator, String thisProduct, StateBase state,
            String prevProductKey, String classLoaderKey) {
        this.useSmartClassLoading = useSmartClassLoading;
        this.instantiator = instantiator;
        this.thisProduct = thisProduct;
        this.state = state;
        this.prevProductKey = prevProductKey;
        this.classLoaderKey = classLoaderKey;
    }

    public Object createInstance(String classFqn) throws Exception {
        if (!useSmartClassLoading) {
            return Class.forName(classFqn).newInstance();
        }
        URLClassLoader classLoader;
        String prevProduct = (String) state.get(prevProductKey);
        if (prevProduct == null || !prevProduct.equals(thisProduct)) {
            classLoader = Utils.buildProductSpecificClassLoader(thisProduct, instantiator.getClassLoader());
            state.put(classLoaderKey, classLoader);
            state.put(prevProductKey, thisProduct);
        } else {//same product and there is a class loader
            classLoader = (URLClassLoader) state.get(classLoaderKey);
        }
        log.info("Creating newInstance " + classFqn + " with classloader " + classLoader);
        Thread.currentThread().setContextClassLoader(classLoader);
        return classLoader.loadClass(classFqn).newInstance();
    }
}