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* JBoss, Home of Professional Open Source
* Copyright 2011, Red Hat Middleware LLC, and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* 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 org.jboss.shrinkwrap.api;
import java.util.logging.Level;
import java.util.logging.Logger;
Utilities to search a series of ClassLoader
s for a Class
by name. Not to be granted visibility outside of this package, unless scoped out to internals (this is not part of the public user API) Author: Andrew Lee Rubinger
/**
* Utilities to search a series of {@link ClassLoader}s for a {@link Class} by name.
*
* Not to be granted visibility outside of this package, unless scoped out to internals (this is not part of the public
* user API)
*
* @author <a href="mailto:alr@jboss.org">Andrew Lee Rubinger</a>
*/
class ClassLoaderSearchUtil {
// -------------------------------------------------------------------------------------||
// Class Members ----------------------------------------------------------------------||
// -------------------------------------------------------------------------------------||
Logger
/**
* Logger
*/
private static final Logger log = Logger.getLogger(ClassLoaderSearchUtil.class.getName());
// -------------------------------------------------------------------------------------||
// Constructor ------------------------------------------------------------------------||
// -------------------------------------------------------------------------------------||
No instances, keep private
/**
* No instances, keep private
*/
private ClassLoaderSearchUtil() {
throw new UnsupportedOperationException("No instances permitted");
}
// -------------------------------------------------------------------------------------||
// Functional Methods -----------------------------------------------------------------||
// -------------------------------------------------------------------------------------||
Finds a Class
by name using a series of ClassLoader
s as the search path Params: - className –
- classLoaders –
Throws: - ClassNotFoundException – If the
Class
could not be found in any of the specified CLs
Returns:
/**
* Finds a {@link Class} by name using a series of {@link ClassLoader}s as the search path
*
* @param className
* @param classLoaders
* @return
* @throws ClassNotFoundException
* If the {@link Class} could not be found in any of the specified CLs
*/
static Class<?> findClassFromClassLoaders(final String className, final Iterable<ClassLoader> classLoaders)
throws ClassNotFoundException, IllegalArgumentException {
// Precondition checks
assert className != null && className.length() > 0 : "Class Name must be specified";
assert classLoaders != null : "ClassLoaders as search path must be specified";
// Find the class by searching through the CLs in order
Class<?> clazz = null;
for (final ClassLoader cl : classLoaders) {
try {
clazz = Class.forName(className, false, cl);
if (log.isLoggable(Level.FINER)) {
log.finer("Found requested class " + clazz.getName() + " from ClassLoader "
+ clazz.getClassLoader());
}
} catch (final ClassNotFoundException cnfe) {
// Ignore here, try the next
}
}
// If we haven't got a class yet, now we need to show we've got CNFE
if (clazz == null) {
throw new ClassNotFoundException("Could not find requested class \"" + className
+ "\" in any of the associated ClassLoaders: " + classLoaders);
}
// Return
return clazz;
}
}