/*
* 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.tuscany.sca.extensibility.equinox;
import java.io.IOException;
import java.net.URL;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.util.Collection;
import java.util.Enumeration;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.apache.tuscany.sca.extensibility.ServiceDeclaration;
import org.apache.tuscany.sca.extensibility.ServiceDeclarationParser;
import org.apache.tuscany.sca.extensibility.ServiceDiscoverer;
import org.osgi.framework.Bundle;
import org.osgi.framework.BundleContext;
import org.osgi.framework.BundleEvent;
import org.osgi.framework.BundleException;
import org.osgi.framework.Constants;
import org.osgi.framework.Version;
import org.osgi.util.tracker.BundleTracker;
/**
* A ServiceDiscoverer that find META-INF/services/... in installed bundles
*
* @version $Rev: 1004317 $ $Date: 2010-10-04 17:32:06 +0100 (Mon, 04 Oct 2010) $
*/
public class EquinoxServiceDiscoverer implements ServiceDiscoverer {
private static final Logger logger = Logger.getLogger(EquinoxServiceDiscoverer.class.getName());
private BundleContext context;
private Version version;
private BundleTracker bundleTracker;
public EquinoxServiceDiscoverer(BundleContext context) {
this.context = context;
Bundle bundle = context.getBundle();
this.version = getSCAVersion(bundle);
if (this.version.equals(Version.emptyVersion)) {
this.version = Version.parseVersion("1.1");
}
bundleTracker = new ActiveBundleTracker(context);
bundleTracker.open();
}
public void stop() {
bundleTracker.close();
}
private Version getSCAVersion(Bundle bundle) {
String header = (String)bundle.getHeaders().get("SCA-Version");
return Version.parseVersion(header);
}
public static class ActiveBundleTracker extends BundleTracker {
/**
* @param context
* @param stateMask
* @param customizer
*/
public ActiveBundleTracker(BundleContext context) {
super(context, Bundle.RESOLVED | Bundle.ACTIVE | Bundle.STARTING, null);
}
@Override
public Object addingBundle(Bundle bundle, BundleEvent event) {
if (event != null && event.getType() == BundleEvent.STOPPED) {
return null;
}
return super.addingBundle(bundle, event);
}
}
public static class ServiceDeclarationImpl implements ServiceDeclaration {
private Bundle bundle;
private URL url;
private String className;
private Class<?> javaClass;
private Map<String, String> attributes;
public ServiceDeclarationImpl(Bundle bundle, URL url, String className, Map<String, String> attributes) {
super();
this.bundle = bundle;
this.url = url;
this.className = className;
this.attributes = attributes;
}
public Map<String, String> getAttributes() {
return attributes;
}
public String getClassName() {
return className;
}
public Class<?> loadClass() throws ClassNotFoundException {
if (className == null) {
return null;
}
if (javaClass == null) {
javaClass = loadClass(className);
}
return javaClass;
}
public Class<?> loadClass(String className) throws ClassNotFoundException {
return bundle.loadClass(className);
}
public URL getLocation() {
return url;
}
public URL getResource(final String name) {
return AccessController.doPrivileged(new PrivilegedAction<URL>() {
public URL run() {
return bundle.getResource(name);
}
});
}
@Override
public String toString() {
StringBuffer sb = new StringBuffer();
sb.append("Bundle: ").append(EquinoxServiceDiscoverer.toString(bundle));
sb.append(" Resource: ").append(url);
sb.append(" Attributes: ").append(attributes);
return sb.toString();
}
public Bundle getBundle() {
return bundle;
}
public boolean isAssignableTo(Class<?> serviceType) {
try {
loadClass();
} catch (ClassNotFoundException e) {
// Ignore
}
return (javaClass != null && serviceType.isAssignableFrom(javaClass));
}
@Override
public Enumeration<URL> getResources(final String name) throws IOException {
return (Enumeration<URL>) bundle.getResources(name);
}
}
/**
* Empty static method to trigger the activation of this bundle.
*/
public static void init() {
}
private static String toString(Bundle b) {
StringBuffer sb = new StringBuffer();
sb.append(b.getBundleId()).append(" ").append(b.getSymbolicName());
int s = b.getState();
if ((s & Bundle.UNINSTALLED) != 0) {
sb.append(" UNINSTALLED");
}
if ((s & Bundle.INSTALLED) != 0) {
sb.append(" INSTALLED");
}
if ((s & Bundle.RESOLVED) != 0) {
sb.append(" RESOLVED");
}
if ((s & Bundle.STARTING) != 0) {
sb.append(" STARTING");
}
if ((s & Bundle.STOPPING) != 0) {
sb.append(" STOPPING");
}
if ((s & Bundle.ACTIVE) != 0) {
sb.append(" ACTIVE");
}
return sb.toString();
}
public ServiceDeclaration getServiceDeclaration(String name) throws IOException {
Collection<ServiceDeclaration> declarations = getServiceDeclarations(name);
if (declarations.isEmpty()) {
return null;
} else {
return declarations.iterator().next();
}
}
private boolean isProviderBundle(Bundle bundle, boolean isTuscanyService) {
if (bundle.getBundleId() == 0 || bundle.getSymbolicName().startsWith("1.x-osgi-bundle")
|| bundle.getHeaders().get(Constants.FRAGMENT_HOST) != null) {
// Skip system bundle as it has access to the application classloader
// Skip the 1.x runtime bundle as this has 1.x services in it
// For testing running 1.x and 2.x in same VM.
// Don't know what final form will be yet.
// Skip bundle fragments too
return false;
}
// FIXME: [rfeng] What bundles should be searched? ACTIVE and STARTING?
if ((bundle.getState() & Bundle.UNINSTALLED) != 0) {
return false;
}
if (isTuscanyService) {
Version scaVersion = getSCAVersion(bundle);
return scaVersion.compareTo(version) == 0;
}
return true;
}
protected Collection<Bundle> getBundles(boolean isTuscanyService) {
// return bundles.keySet();
Set<Bundle> set = new HashSet<Bundle>();
for (Bundle b : context.getBundles()) {
if (isProviderBundle(b, isTuscanyService)) {
set.add(b);
}
/*
else {
if (b.getBundleId() != 0 && isTuscanyService) {
logger.warning("Bundle is skipped for service discovery: " + toString(b));
}
}
*/
}
return set;
}
public Collection<ServiceDeclaration> getServiceDeclarations(String serviceName) throws IOException {
boolean debug = logger.isLoggable(Level.FINE);
Collection<ServiceDeclaration> descriptors = new HashSet<ServiceDeclaration>();
// http://java.sun.com/j2se/1.5.0/docs/api/javax/xml/xpath/XPathFactory.html
boolean isPropertyFile = "javax.xml.xpath.XPathFactory".equals(serviceName);
boolean isTuscanyService = serviceName.startsWith("org.apache.tuscany.sca.");
if (serviceName.startsWith("/")) {
// If the service name starts with /, treat it as the entry name
serviceName = serviceName.substring(1);
} else {
// Use JDK SPI pattern
serviceName = "META-INF/services/" + serviceName;
}
Set<URL> visited = new HashSet<URL>();
//System.out.println(">>>> getServiceDeclarations()");
for (Bundle bundle : getBundles(isTuscanyService)) {
// if (!isProviderBundle(bundle)) {
// continue;
// }
Enumeration<URL> urls = null;
try {
// Use getResources to find resources on the classpath of the bundle
// Please note there are cases that getResources will return null even
// the bundle containing such entries:
// 1. There is a match on Import-Package or DynamicImport-Package, and another
// bundle exports the resource package, there is a possiblity that it doesn't
// find the containing entry
// 2. The bundle cannot be resolved, then getResources will return null
urls = bundle.getResources(serviceName);
if (urls == null) {
URL entry = bundle.getEntry(serviceName);
if (entry != null) {
logger.warning("Unresolved resource " + serviceName + " found in bundle: " + toString(bundle));
try {
bundle.start();
} catch (BundleException e) {
logger.log(Level.SEVERE, "Bundle: " + bundle.getSymbolicName() + " - " + e.getMessage(), e);
}
// urls = Collections.enumeration(Arrays.asList(entry));
}
}
} catch (IOException e) {
logger.log(Level.SEVERE, "Bundle: " + bundle.getSymbolicName() + " - " + e.getMessage(), e);
}
if (urls == null) {
continue;
}
while (urls.hasMoreElements()) {
final URL url = urls.nextElement();
if (!visited.add(url)) {
// The URL has already been processed
continue;
}
if (debug) {
logger.fine("Reading service provider file: " + url.toExternalForm());
}
try {
for (Map<String, String> attributes : ServiceDeclarationParser.load(url, isPropertyFile)) {
String className = attributes.get("class");
ServiceDeclarationImpl descriptor =
new ServiceDeclarationImpl(bundle, url, className, attributes);
descriptors.add(descriptor);
}
} catch (IOException e) {
logger.log(Level.SEVERE, "Bundle: " + bundle.getSymbolicName() + " - " + e.getMessage(), e);
}
}
}
return descriptors;
}
public ClassLoader getContextClassLoader() {
// Get the bundle classloader for the extensibility bundle that has DynamicImport-Package *
return getClass().getClassLoader();
}
}