/**
* Copyright 2003-2008 Luck Consulting Pty Ltd
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.sf.ehcache.util;
import net.sf.ehcache.CacheException;
/**
* Keeps all classloading in ehcache consistent.
*
* @author Greg Luck
* @version $Id: ClassLoaderUtil.java 744 2008-08-16 20:10:49Z gregluck $
*/
public final class ClassLoaderUtil {
/**
* Utility class.
*/
private ClassLoaderUtil() {
//noop
}
/**
* Gets the <code>ClassLoader</code> that all classes in ehcache, and extensions, should
* use for classloading. All ClassLoading in ehcache should use this one. This is the only
* thing that seems to work for all of the class loading situations found in the wild.
* @return the thread context class loader.
*/
public static ClassLoader getStandardClassLoader() {
return Thread.currentThread().getContextClassLoader();
}
/**
* Gets a fallback <code>ClassLoader</code> that all classes in ehcache, and extensions,
* should use for classloading. This is used if the context class loader does not work.
* @return the <code>ClassLoaderUtil.class.getClassLoader();</code>
*/
public static ClassLoader getFallbackClassLoader() {
return ClassLoaderUtil.class.getClassLoader();
}
/**
* Creates a new class instance. Logs errors along the way. Classes are loaded using the
* ehcache standard classloader.
*
* @param className a fully qualified class name
* @return null if the instance cannot be loaded
*/
public static Object createNewInstance(String className) throws CacheException {
Class clazz;
Object newInstance;
try {
clazz = Class.forName(className, true, getStandardClassLoader());
} catch (ClassNotFoundException e) {
//try fallback
try {
clazz = Class.forName(className, true, getFallbackClassLoader());
} catch (ClassNotFoundException ex) {
throw new CacheException("Unable to load class " + className +
". Initial cause was " + e.getMessage(), e);
}
}
try {
newInstance = clazz.newInstance();
} catch (IllegalAccessException e) {
throw new CacheException("Unable to load class " + className +
". Initial cause was " + e.getMessage(), e);
} catch (InstantiationException e) {
throw new CacheException("Unable to load class " + className +
". Initial cause was " + e.getMessage(), e);
}
return newInstance;
}
}