package org.aspectj.apache.bcel.util;
/* ====================================================================
* The Apache Software License, Version 1.1
*
* Copyright (c) 2001 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Apache" and "Apache Software Foundation" and
* "Apache BCEL" must not be used to endorse or promote products
* derived from this software without prior written permission. For
* written permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* "Apache BCEL", nor may "Apache" appear in their name, without
* prior written permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
import java.io.IOException;
import java.io.InputStream;
import java.lang.ref.ReferenceQueue;
import java.lang.ref.SoftReference;
import java.net.URL;
import java.net.URLClassLoader;
import java.util.AbstractMap;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import org.aspectj.apache.bcel.classfile.ClassParser;
import org.aspectj.apache.bcel.classfile.JavaClass;
/**
* The repository maintains information about which classes have been loaded.
*
* It loads its data from the ClassLoader implementation passed into its constructor.
*
* @see org.aspectj.apache.bcel.Repository
*
* @version $Id: NonCachingClassLoaderRepository.java,v 1.6 2009/09/09 19:56:20 aclement Exp $
* @author <A HREF="mailto:markus.dahm@berlin.de">M. Dahm</A>
* @author David Dixon-Peugh
*
*/
public class NonCachingClassLoaderRepository implements Repository {
private static java.lang.ClassLoader bootClassLoader = null;
private final ClassLoaderReference loaderRef;
private final Map<String, JavaClass> loadedClasses = new SoftHashMap(); // CLASSNAME X JAVACLASS
public static class SoftHashMap extends AbstractMap {
private Map<Object, SpecialValue> map;
private ReferenceQueue rq = new ReferenceQueue();
public SoftHashMap(Map<Object, SpecialValue> map) {
this.map = map;
}
public SoftHashMap() {
this(new HashMap());
}
public SoftHashMap(Map map, boolean b) {
this(map);
}
class SpecialValue extends SoftReference {
private final Object key;
SpecialValue(Object k, Object v) {
super(v, rq);
this.key = k;
}
}
private void processQueue() {
SpecialValue sv = null;
while ((sv = (SpecialValue) rq.poll()) != null) {
map.remove(sv.key);
}
}
@Override
public Object get(Object key) {
SpecialValue value = map.get(key);
if (value == null)
return null;
if (value.get() == null) {
// it got GC'd
map.remove(value.key);
return null;
} else {
return value.get();
}
}
@Override
public Object put(Object k, Object v) {
processQueue();
return map.put(k, new SpecialValue(k, v));
}
@Override
public Set entrySet() {
return map.entrySet();
}
@Override
public void clear() {
processQueue();
Set<Object> keys = map.keySet();
for (Iterator<Object> iterator = keys.iterator(); iterator.hasNext();) {
Object name = iterator.next();
map.remove(name);
}
}
@Override
public int size() {
processQueue();
return map.size();
}
@Override
public Object remove(Object k) {
processQueue();
SpecialValue value = map.remove(k);
if (value == null)
return null;
if (value.get() != null) {
return value.get();
}
return null;
}
}
public NonCachingClassLoaderRepository(java.lang.ClassLoader loader) {
this.loaderRef = new DefaultClassLoaderReference((loader != null) ? loader : getBootClassLoader());
}
public NonCachingClassLoaderRepository(ClassLoaderReference loaderRef) {
this.loaderRef = loaderRef;
}
private static synchronized java.lang.ClassLoader getBootClassLoader() {
if (bootClassLoader == null) {
bootClassLoader = new URLClassLoader(new URL[0]);
}
return bootClassLoader;
}
/**
* Store a new JavaClass into this Repository.
*/
public void storeClass(JavaClass clazz) {
synchronized (loadedClasses) {
loadedClasses.put(clazz.getClassName(), clazz);
}
clazz.setRepository(this);
}
/**
* Remove class from repository
*/
public void removeClass(JavaClass clazz) {
synchronized (loadedClasses) {
loadedClasses.remove(clazz.getClassName());
}
}
/**
* Find an already defined JavaClass.
*/
public JavaClass findClass(String className) {
synchronized (loadedClasses) {
if (loadedClasses.containsKey(className)) {
return loadedClasses.get(className);
} else {
return null;
}
}
}
/**
* Clear all entries from cache.
*/
public void clear() {
synchronized (loadedClasses) {
loadedClasses.clear();
}
}
/**
* Lookup a JavaClass object from the Class Name provided.
*/
public JavaClass loadClass(String className) throws ClassNotFoundException {
JavaClass javaClass = findClass(className);
if (javaClass != null) {
return javaClass;
}
javaClass = loadJavaClass(className);
storeClass(javaClass);
return javaClass;
}
public JavaClass loadClass(Class clazz) throws ClassNotFoundException {
return loadClass(clazz.getName());
}
private JavaClass loadJavaClass(String className) throws ClassNotFoundException {
String classFile = className.replace('.', '/');
try {
InputStream is = loaderRef.getClassLoader().getResourceAsStream(classFile + ".class");
if (is == null) {
throw new ClassNotFoundException(className + " not found.");
}
ClassParser parser = new ClassParser(is, className);
return parser.parse();
} catch (IOException e) {
throw new ClassNotFoundException(e.toString());
}
}
}