modules/extensibility-equinox/src/main/java/org/apache/tuscany/sca/extensibility/equinox/EquinoxServiceDiscoverer.java - tuscany-sca-2.x - Git at Google

 /*
  * 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 $Rev$ $Date$
  */
 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));
         }

     }

     /**
      * 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.");
         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 " + toString(bundle));
                         try {
                             bundle.start();
                         } catch (BundleException e) {
                             logger.log(Level.SEVERE, e.getMessage(), e);
                         }
                         // urls = Collections.enumeration(Arrays.asList(entry));
                     }
                 }
             } catch (IOException e) {
                 logger.log(Level.SEVERE, 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, e.getMessage(), e);
                 }
             }
         }
         return descriptors;
     }

     public ClassLoader getContextClassLoader() {
         // Get the bundle classloader for the extensibility bundle that has DynamicImport-Package *
         return getClass().getClassLoader();
     }

 }
	/*
	* 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 $Rev$ $Date$
	*/
	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));
	}

	}

	/**
	* 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.");
	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 " + toString(bundle));
	try {
	bundle.start();
	} catch (BundleException e) {
	logger.log(Level.SEVERE, e.getMessage(), e);
	}
	// urls = Collections.enumeration(Arrays.asList(entry));
	}
	}
	} catch (IOException e) {
	logger.log(Level.SEVERE, 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, e.getMessage(), e);
	}
	}
	}
	return descriptors;
	}

	public ClassLoader getContextClassLoader() {
	// Get the bundle classloader for the extensibility bundle that has DynamicImport-Package *
	return getClass().getClassLoader();
	}

	}