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This is the ehcache core module. Pair it with other modules for added functionality.
/**
* Copyright Terracotta, Inc.
*
* 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 java.lang.reflect.Constructor;
import java.lang.reflect.InvocationTargetException;
import net.sf.ehcache.CacheException;
/**
* Keeps all classloading in ehcache consistent.
*
* @author Greg Luck
* @version $Id: ClassLoaderUtil.java 5631 2012-05-10 08:31:33Z teck $
*/
public final class ClassLoaderUtil {
/**
* Utility class.
*/
private ClassLoaderUtil() {
//noop
}
/**
* Gets the ClassLoader
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 ClassLoader
that all classes in ehcache, and extensions,
* should use for classloading. This is used if the context class loader does not work.
* @return the ClassLoaderUtil.class.getClassLoader();
*/
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 the newly created instance
* @throws CacheException if instance cannot be created due to a missing class or exception
*/
public static Object createNewInstance(String className) throws CacheException {
return createNewInstance(className, new Class[0], new Object[0]);
}
/**
* Creates a new class instance and passes args to the constructor call. Logs errors along the way.
* Classes are loaded using the ehcache standard classloader.
*
* @param className a fully qualified class name
* @param argTypes Types for constructor argument parameters
* @param args Values for constructor argument parameters
* @return the newly created instance
* @throws CacheException if instance cannot be created due to a missing class or exception
*/
public static Object createNewInstance(String className, Class[] argTypes, Object[] args) throws CacheException {
Class clazz;
Object newInstance;
try {
clazz = loadClass(className);
} catch (ClassNotFoundException e) {
throw new CacheException("Unable to load class " + className +
". Initial cause was " + e.getMessage(), e);
}
try {
Constructor constructor = clazz.getConstructor(argTypes);
newInstance = constructor.newInstance(args);
} 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);
} catch (NoSuchMethodException e) {
throw new CacheException("Unable to load class " + className +
". Initial cause was " + e.getMessage(), e);
} catch (SecurityException e) {
throw new CacheException("Unable to load class " + className +
". Initial cause was " + e.getMessage(), e);
} catch (IllegalArgumentException e) {
throw new CacheException("Unable to load class " + className +
". Initial cause was " + e.getMessage(), e);
} catch (InvocationTargetException e) {
throw new CacheException("Unable to load class " + className +
". Initial cause was " + e.getCause().getMessage(), e.getCause());
}
return newInstance;
}
/**
* Load the given class by name
*
* @param className a fully qualified class name
* @return Class the loaded class
* @throws ClassNotFoundException if the class cannot be loaded
* @since 1.7
*/
public static Class loadClass(String className) throws ClassNotFoundException {
Class clazz;
try {
clazz = Class.forName(className, true, getStandardClassLoader());
} catch (ClassNotFoundException e) {
//try fallback
clazz = Class.forName(className, true, getFallbackClassLoader());
}
return clazz;
}
}