/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.apache.xbean.osgi.bundle.util;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Dictionary;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.CopyOnWriteArrayList;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleException;
import org.osgi.framework.Constants;
import org.osgi.framework.ServiceReference;
import org.osgi.framework.Version;
import org.osgi.framework.wiring.BundleCapability;
import org.osgi.framework.wiring.BundleRevision;
import org.osgi.framework.wiring.BundleWiring;
/**
* Bundle that delegates ClassLoader operations to a collection of {@link Bundle} objects.
*
* @version $Rev: 1371482 $ $Date: 2012-08-09 20:58:28 +0000 (Thu, 09 Aug 2012) $
*/
public class DelegatingBundle implements Bundle {
private static final String PACKAGE_CACHE = DelegatingBundle.class.getName() + ".packageCache";
private static final String RESOURCE_CACHE_SIZE = DelegatingBundle.class.getName() + ".resourceCacheSize";
private static final URL NOT_FOUND_RESOURCE;
static {
try {
NOT_FOUND_RESOURCE = new URL("file://foo");
} catch (MalformedURLException e) {
throw new Error(e);
}
}
private CopyOnWriteArrayList<Bundle> bundles;
private Bundle bundle;
private BundleContext bundleContext;
private final boolean hasDynamicImports;
private final Map<String, URL> resourceCache;
private final boolean packageCacheEnabled;
private Map<String, Bundle> packageCache;
public DelegatingBundle(Collection<Bundle> bundles) {
if (bundles.isEmpty()) {
throw new IllegalArgumentException("At least one bundle is required");
}
this.bundles = new CopyOnWriteArrayList<Bundle>(bundles);
Iterator<Bundle> iterator = bundles.iterator();
// assume first Bundle is the main bundle
this.bundle = iterator.next();
this.bundleContext = new DelegatingBundleContext(this, bundle.getBundleContext());
this.hasDynamicImports = hasDynamicImports(iterator);
this.resourceCache = initResourceCache();
this.packageCacheEnabled = initPackageCacheEnabled();
}
public DelegatingBundle(Bundle bundle) {
this(Collections.singletonList(bundle));
}
private static Map<String, URL> initResourceCache() {
String value = System.getProperty(RESOURCE_CACHE_SIZE, "250");
int size = Integer.parseInt(value);
if (size > 0) {
return Collections.synchronizedMap(new Cache<String, URL>(size));
} else {
return null;
}
}
private static boolean initPackageCacheEnabled() {
String value = System.getProperty(PACKAGE_CACHE, "true");
boolean enabled = Boolean.parseBoolean(value);
return enabled;
}
/*
* Returns true if a single bundle has Dynamic-ImportPackage: *. False, otherwise.
*/
private boolean hasDynamicImports(Iterator<Bundle> iterator) {
while (iterator.hasNext()) {
Bundle delegate = iterator.next();
if (hasWildcardDynamicImport(delegate)) {
return true;
}
}
return false;
}
private synchronized Map<String, Bundle> getPackageBundleMap() {
if (packageCache == null) {
packageCache = buildPackageBundleMap();
}
return packageCache;
}
private synchronized void reset() {
resourceCache.clear();
packageCache = null;
}
private Map<String, Bundle> buildPackageBundleMap() {
Map<String, Bundle> map = new HashMap<String, Bundle>();
Iterator<Bundle> iterator = bundles.iterator();
// skip first bundle
iterator.next();
// attempt to load the class from the remaining bundles
while (iterator.hasNext()) {
Bundle bundle = iterator.next();
BundleWiring wiring = bundle.adapt(BundleWiring.class);
if (wiring != null) {
List<BundleCapability> capabilities = wiring.getCapabilities(BundleRevision.PACKAGE_NAMESPACE);
if (capabilities != null && !capabilities.isEmpty()) {
for (BundleCapability capability : capabilities) {
Map<String, Object> attributes = capability.getAttributes();
if (attributes != null) {
String packageName = String.valueOf(attributes.get(BundleRevision.PACKAGE_NAMESPACE));
if (!map.containsKey(packageName)) {
map.put(packageName, bundle);
}
}
}
}
}
}
return map;
}
public Bundle getMainBundle() {
return bundle;
}
public Class<?> loadClass(String name) throws ClassNotFoundException {
try {
Class<?> clazz = bundle.loadClass(name);
return clazz;
} catch (ClassNotFoundException cnfe) {
if (name.startsWith("java.")) {
throw cnfe;
}
int index = name.lastIndexOf('.');
if (index > 0 && bundles.size() > 1) {
String packageName = name.substring(0, index);
if (packageCacheEnabled) {
return findCachedClass(name, packageName, cnfe);
} else {
return findClass(name, packageName, cnfe);
}
}
throw cnfe;
}
}
private Class<?> findCachedClass(String className, String packageName, ClassNotFoundException cnfe) throws ClassNotFoundException {
Map<String, Bundle> map = getPackageBundleMap();
Bundle bundle = map.get(packageName);
if (bundle == null) {
// Work-around for Introspector always looking for classes in sun.beans.infos
if (packageName.equals("sun.beans.infos") && className.endsWith("BeanInfo")) {
throw cnfe;
}
return findClass(className, packageName, cnfe);
} else {
return bundle.loadClass(className);
}
}
private Class<?> findClass(String className, String packageName, ClassNotFoundException cnfe) throws ClassNotFoundException {
Iterator<Bundle> iterator = bundles.iterator();
// skip first bundle
iterator.next();
while (iterator.hasNext()) {
Bundle delegate = iterator.next();
if (hasDynamicImports && hasWildcardDynamicImport(delegate)) {
// skip any bundles with Dynamic-ImportPackage: * to avoid unnecessary wires
continue;
}
try {
return delegate.loadClass(className);
} catch (ClassNotFoundException e) {
// ignore
}
}
throw cnfe;
}
private static boolean hasWildcardDynamicImport(Bundle bundle) {
Dictionary<String, String> headers = bundle.getHeaders();
if (headers != null) {
String value = headers.get(Constants.DYNAMICIMPORT_PACKAGE);
if (value == null) {
return false;
} else {
return "*".equals(value.trim());
}
} else {
return false;
}
}
public void addBundle(Bundle b) {
bundles.add(b);
reset();
}
public void removeBundle(Bundle b) {
bundles.remove(b);
reset();
}
public URL getResource(String name) {
URL resource = null;
if (resourceCache == null) {
resource = findResource(name);
} else {
resource = findCachedResource(name);
}
return resource;
}
private URL findCachedResource(String name) {
URL resource = bundle.getResource(name);
if (resource == null) {
resource = resourceCache.get(name);
if (resource == null) {
Iterator<Bundle> iterator = bundles.iterator();
// skip first bundle
iterator.next();
// look for resource in the remaining bundles
resource = findResource(name, iterator);
resourceCache.put(name, (resource == null) ? NOT_FOUND_RESOURCE : resource);
} else if (resource == NOT_FOUND_RESOURCE) {
resource = null;
}
}
return resource;
}
private URL findResource(String name) {
Iterator<Bundle> iterator = bundles.iterator();
return findResource(name, iterator);
}
private URL findResource(String name, Iterator<Bundle> iterator) {
URL resource = null;
while (iterator.hasNext() && resource == null) {
Bundle delegate = iterator.next();
resource = delegate.getResource(name);
}
return resource;
}
public Enumeration<URL> getResources(String name) throws IOException {
ArrayList<URL> allResources = new ArrayList<URL>();
for (Bundle bundle : bundles) {
Enumeration<URL> e = bundle.getResources(name);
addToList(allResources, e);
}
return Collections.enumeration(allResources);
}
private static void addToList(List<URL> list, Enumeration<URL> enumeration) {
if (enumeration != null) {
while (enumeration.hasMoreElements()) {
list.add(enumeration.nextElement());
}
}
}
public BundleContext getBundleContext() {
return bundleContext;
}
public Enumeration findEntries(String arg0, String arg1, boolean arg2) {
return bundle.findEntries(arg0, arg1, arg2);
}
public long getBundleId() {
return bundle.getBundleId();
}
public URL getEntry(String arg0) {
return bundle.getEntry(arg0);
}
public Enumeration getEntryPaths(String arg0) {
return bundle.getEntryPaths(arg0);
}
public Dictionary getHeaders() {
return bundle.getHeaders();
}
public Dictionary getHeaders(String arg0) {
return bundle.getHeaders(arg0);
}
public long getLastModified() {
return bundle.getLastModified();
}
public String getLocation() {
return bundle.getLocation();
}
public ServiceReference[] getRegisteredServices() {
return bundle.getRegisteredServices();
}
public ServiceReference[] getServicesInUse() {
return bundle.getServicesInUse();
}
public Map getSignerCertificates(int arg0) {
return bundle.getSignerCertificates(arg0);
}
public int getState() {
return bundle.getState();
}
public String getSymbolicName() {
return bundle.getSymbolicName();
}
public Version getVersion() {
return bundle.getVersion();
}
public boolean hasPermission(Object arg0) {
return bundle.hasPermission(arg0);
}
public void start() throws BundleException {
bundle.start();
}
public void start(int arg0) throws BundleException {
bundle.start(arg0);
}
public void stop() throws BundleException {
bundle.stop();
}
public void stop(int arg0) throws BundleException {
bundle.stop(arg0);
}
public void uninstall() throws BundleException {
bundle.uninstall();
}
public void update() throws BundleException {
bundle.update();
}
public void update(InputStream arg0) throws BundleException {
bundle.update(arg0);
}
public int compareTo(Bundle other) {
return bundle.compareTo(other);
}
public <A> A adapt(Class<A> type) {
return bundle.adapt(type);
}
public File getDataFile(String filename) {
return bundle.getDataFile(filename);
}
public String toString() {
return "[DelegatingBundle: " + bundles + "]";
}
private static class Cache<K, V> extends LinkedHashMap<K, V> {
private final int maxSize;
public Cache(int maxSize) {
this(16, maxSize, 0.75f);
}
public Cache(int initialSize, int maxSize, float loadFactor) {
super(initialSize, loadFactor, true);
this.maxSize = maxSize;
}
@Override
protected boolean removeEldestEntry(Map.Entry<K, V> eldest) {
if (size() > maxSize) {
return true;
} else {
return false;
}
}
}
}