extender/src/main/java/org/eclipse/gemini/blueprint/extender/internal/support/ExtenderConfiguration.java - gemini.blueprint/org.eclipse.gemini.blueprint - Git at Google

 /******************************************************************************
  * Copyright (c) 2006, 2010 VMware Inc.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Apache License v2.0 which accompanies this distribution.
  * The Eclipse Public License is available at
  * http://www.eclipse.org/legal/epl-v10.html and the Apache License v2.0
  * is available at http://www.opensource.org/licenses/apache2.0.php.
  * You may elect to redistribute this code under either of these licenses.
  *
  * Contributors:
  *   VMware Inc.
  *****************************************************************************/

 package org.eclipse.gemini.blueprint.extender.internal.support;

 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.eclipse.gemini.blueprint.context.ConfigurableOsgiBundleApplicationContext;
 import org.eclipse.gemini.blueprint.context.event.OsgiBundleApplicationContextEventMulticaster;
 import org.eclipse.gemini.blueprint.context.event.OsgiBundleApplicationContextEventMulticasterAdapter;
 import org.eclipse.gemini.blueprint.context.event.OsgiBundleApplicationContextListener;
 import org.eclipse.gemini.blueprint.context.support.OsgiBundleXmlApplicationContext;
 import org.eclipse.gemini.blueprint.extender.OsgiApplicationContextCreator;
 import org.eclipse.gemini.blueprint.extender.OsgiBeanFactoryPostProcessor;
 import org.eclipse.gemini.blueprint.extender.OsgiServiceDependencyFactory;
 import org.eclipse.gemini.blueprint.extender.internal.dependencies.startup.MandatoryImporterDependencyFactory;
 import org.eclipse.gemini.blueprint.extender.support.internal.ConfigUtils;
 import org.eclipse.gemini.blueprint.util.BundleDelegatingClassLoader;
 import org.osgi.framework.Bundle;
 import org.osgi.framework.BundleActivator;
 import org.osgi.framework.BundleContext;
 import org.springframework.beans.BeanUtils;
 import org.springframework.beans.factory.DisposableBean;
 import org.springframework.context.event.SimpleApplicationEventMulticaster;
 import org.springframework.core.task.TaskExecutor;
 import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
 import org.springframework.util.Assert;
 import org.springframework.util.ObjectUtils;

 import java.io.UnsupportedEncodingException;
 import java.net.URL;
 import java.net.URLDecoder;
 import java.util.*;

 /**
  * Configuration class for the extender. Takes care of locating the extender specific configurations and merging the
  * results with the defaults.
  *
  * @author Costin Leau
  */
 public class ExtenderConfiguration implements BundleActivator {

 	/** logger */
     protected final Log log = LogFactory.getLog(getClass());

     private static final String TASK_EXECUTOR_NAME = "taskExecutor";

 	private static final String SHUTDOWN_TASK_EXECUTOR_NAME = "shutdownTaskExecutor";

 	private static final String CONTEXT_CREATOR_NAME = "applicationContextCreator";

 	private static final String APPLICATION_EVENT_MULTICASTER_BEAN_NAME = "osgiApplicationEventMulticaster";

 	private static final String CONTEXT_LISTENER_NAME = "osgiApplicationContextListener";

 	private static final String PROPERTIES_NAME = "extenderProperties";

     private static final String SHUTDOWN_ASYNCHRONOUS_KEY = "shutdown.asynchronously";

 	private static final String SHUTDOWN_WAIT_KEY = "shutdown.wait.time";

 	private static final String PROCESS_ANNOTATIONS_KEY = "process.annotations";

 	private static final String WAIT_FOR_DEPS_TIMEOUT_KEY = "dependencies.wait.time";

 	private static final String EXTENDER_CFG_LOCATION = "META-INF/spring/extender";

 	private static final String XML_PATTERN = "*.xml";

 	private static final String ANNOTATION_DEPENDENCY_FACTORY =
 			"org.eclipse.gemini.blueprint.extensions.annotation.ServiceReferenceDependencyBeanFactoryPostProcessor";

 	/** annotation processing system property (kept for backwards compatibility) */
 	private static final String AUTO_ANNOTATION_PROCESSING =
 			"org.eclipse.gemini.blueprint.extender.annotation.auto.processing";

 	//
 	// defaults
 	//

 	// default dependency wait time (in milliseconds)
 	private static final long DEFAULT_DEP_WAIT = ConfigUtils.DIRECTIVE_TIMEOUT_DEFAULT * 1000;
 	private static final boolean DEFAULT_NS_BUNDLE_STATE = true;
 	private static final boolean DEFAULT_SHUTDOWN_ASYNCHRONOUS = true;
     private static final long DEFAULT_SHUTDOWN_WAIT = 10 * 1000;

 	private static final boolean DEFAULT_PROCESS_ANNOTATION = true;

 	private ConfigurableOsgiBundleApplicationContext extenderConfiguration;

 	private TaskExecutor taskExecutor, shutdownTaskExecutor;

 	private boolean isTaskExecutorManagedInternally;

 	private boolean isShutdownTaskExecutorManagedInternally;

 	private boolean isMulticasterManagedInternally;

 	private long shutdownWaitTime, dependencyWaitTime;

     private boolean shutdownAsynchronously;

 	private boolean processAnnotation, nsBundledResolved;

 	private OsgiBundleApplicationContextEventMulticaster eventMulticaster;

 	private OsgiBundleApplicationContextListener contextEventListener;

 	private boolean forceThreadShutdown;

 	private OsgiApplicationContextCreator contextCreator = null;

 	/** bundle wrapped class loader */
 	private ClassLoader classLoader;
 	/** List of context post processors */
 	private final List<OsgiBeanFactoryPostProcessor> postProcessors =
 			Collections.synchronizedList(new ArrayList<OsgiBeanFactoryPostProcessor>(0));
 	/** List of service dependency factories */
 	private final List<OsgiServiceDependencyFactory> dependencyFactories =
 			Collections.synchronizedList(new ArrayList<OsgiServiceDependencyFactory>(0));

 	// fields reading/writing lock
 	private final Object lock = new Object();

     /**
 	 * Constructs a new <code>ExtenderConfiguration</code> instance. Locates the extender configuration, creates an
 	 * application context which will returned the extender items.
 	 *
 	 * @param extenderBundleContext extender OSGi bundle context
 	 */
 	public void start(BundleContext extenderBundleContext) {
 		Bundle bundle = extenderBundleContext.getBundle();
 		Properties properties = new Properties(createDefaultProperties());

 		Enumeration<?> enm = bundle.findEntries(EXTENDER_CFG_LOCATION, XML_PATTERN, false);

 		if (enm == null) {
 			log.info("No custom extender configuration detected; using defaults...");
 			synchronized (lock) {
 				taskExecutor = createDefaultTaskExecutor();
 				shutdownTaskExecutor = createDefaultShutdownTaskExecutor();
 				eventMulticaster = createDefaultEventMulticaster();
 				contextEventListener = createDefaultApplicationContextListener();
 			}
 			classLoader = BundleDelegatingClassLoader.createBundleClassLoaderFor(bundle);
 		} else {
 			String[] configs = copyEnumerationToList(enm);

 			log.info("Detected extender custom configurations at " + ObjectUtils.nullSafeToString(configs));
 			// create OSGi specific XML context
 			ConfigurableOsgiBundleApplicationContext extenderAppCtx = new OsgiBundleXmlApplicationContext(configs);
 			extenderAppCtx.setBundleContext(extenderBundleContext);
 			extenderAppCtx.refresh();

 			synchronized (lock) {
 				extenderConfiguration = extenderAppCtx;
 				// initialize beans
 				taskExecutor =
 						extenderConfiguration.containsBean(TASK_EXECUTOR_NAME) ? extenderConfiguration
 								.getBean(TASK_EXECUTOR_NAME, TaskExecutor.class) : createDefaultTaskExecutor();

 				shutdownTaskExecutor =
 						extenderConfiguration.containsBean(SHUTDOWN_TASK_EXECUTOR_NAME) ? extenderConfiguration
 								.getBean(SHUTDOWN_TASK_EXECUTOR_NAME, TaskExecutor.class)
 								: createDefaultShutdownTaskExecutor();

 				eventMulticaster =
 						extenderConfiguration.containsBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME) ? extenderConfiguration
 								.getBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME,
 										OsgiBundleApplicationContextEventMulticaster.class)
 								: createDefaultEventMulticaster();

 				contextCreator =
 						extenderConfiguration.containsBean(CONTEXT_CREATOR_NAME) ? extenderConfiguration
 								.getBean(CONTEXT_CREATOR_NAME, OsgiApplicationContextCreator.class)
 								: null;

 				contextEventListener =
 						extenderConfiguration.containsBean(CONTEXT_LISTENER_NAME) ? extenderConfiguration
 								.getBean(CONTEXT_LISTENER_NAME, OsgiBundleApplicationContextListener.class)
 								: createDefaultApplicationContextListener();
 			}

 			// get post processors
 			postProcessors.addAll(extenderConfiguration.getBeansOfType(OsgiBeanFactoryPostProcessor.class).values());

 			// get dependency factories
 			dependencyFactories.addAll(extenderConfiguration.getBeansOfType(OsgiServiceDependencyFactory.class)
 					.values());

 			classLoader = extenderConfiguration.getClassLoader();
 			// extender properties using the defaults as backup
 			if (extenderConfiguration.containsBean(PROPERTIES_NAME)) {
 				Properties customProperties =
 						extenderConfiguration.getBean(PROPERTIES_NAME, Properties.class);
 				Enumeration<?> propertyKey = customProperties.propertyNames();
 				while (propertyKey.hasMoreElements()) {
 					String property = (String) propertyKey.nextElement();
 					properties.setProperty(property, customProperties.getProperty(property));
 				}
 			}
 		}

 		synchronized (lock) {
 			shutdownWaitTime = getShutdownWaitTime(properties);
 			shutdownAsynchronously = getShutdownAsynchronously(properties);
             dependencyWaitTime = getDependencyWaitTime(properties);
 			processAnnotation = getProcessAnnotations(properties);
 		}

 		// load default dependency factories
 		addDefaultDependencyFactories();

 		// allow post processing
 		contextCreator = postProcess(contextCreator);
 	}

 	/**
 	 * Allows post processing of the context creator.
 	 *
 	 * @param contextCreator
 	 * @return
 	 */
 	protected OsgiApplicationContextCreator postProcess(OsgiApplicationContextCreator contextCreator) {
 		return contextCreator;
 	}

 	/**
 	 * {@inheritDoc}
 	 *
 	 * Cleanup the configuration items.
 	 */
 	public void stop(BundleContext extenderBundleContext) {

 		synchronized (lock) {
 			if (isMulticasterManagedInternally) {
 				eventMulticaster.removeAllListeners();
 				eventMulticaster = null;
 			}

 			if (extenderConfiguration != null) {
 				extenderConfiguration.close();
 				extenderConfiguration = null;
 			}

 			// postpone the task executor shutdown
 			if (forceThreadShutdown) {

 				if (isTaskExecutorManagedInternally) {
 					log.warn("Forcing the (internally created) taskExecutor to stop...");
 					ThreadGroup th = ((ThreadPoolTaskExecutor) taskExecutor).getThreadGroup();
 					if (!th.isDestroyed()) {
 						// ask the threads nicely to stop
 						th.interrupt();
 					}
 				}
 				taskExecutor = null;
 			}

 			if (isShutdownTaskExecutorManagedInternally) {
 				try {
 					((DisposableBean) shutdownTaskExecutor).destroy();
 				} catch (Exception ex) {
 					log.debug("Received exception while shutting down shutdown task executor", ex);
 				}
 				shutdownTaskExecutor = null;
 			}
 		}
 	}

 	/**
 	 * Copies the URLs returned by the given enumeration and returns them as an array of Strings for consumption by the
 	 * application context.
 	 *
 	 * @param enm
 	 * @return
 	 */
 	@SuppressWarnings("deprecation")
 	private String[] copyEnumerationToList(Enumeration<?> enm) {
 		List<String> urls = new ArrayList<String>(4);
 		while (enm != null && enm.hasMoreElements()) {
 			URL configURL = (URL) enm.nextElement();
 			if (configURL != null) {
 				String configURLAsString = configURL.toExternalForm();
 				try {
 					urls.add(URLDecoder.decode(configURLAsString, "UTF8"));
 				} catch (UnsupportedEncodingException uee) {
 					log.warn("UTF8 encoding not supported, using the platform default");
 					urls.add(URLDecoder.decode(configURLAsString));
 				}
 			}
 		}

 		return urls.toArray(new String[urls.size()]);
 	}

 	private Properties createDefaultProperties() {
 		Properties properties = new Properties();
 		properties.setProperty(SHUTDOWN_WAIT_KEY, "" + DEFAULT_SHUTDOWN_WAIT);
         properties.setProperty(SHUTDOWN_ASYNCHRONOUS_KEY, "" + DEFAULT_SHUTDOWN_ASYNCHRONOUS);
 		properties.setProperty(PROCESS_ANNOTATIONS_KEY, "" + DEFAULT_PROCESS_ANNOTATION);
 		properties.setProperty(WAIT_FOR_DEPS_TIMEOUT_KEY, "" + DEFAULT_DEP_WAIT);

 		return properties;
 	}

 	protected void addDefaultDependencyFactories() {
 		boolean debug = log.isDebugEnabled();

 		// default JDK 1.4 processor
 		dependencyFactories.add(0, new MandatoryImporterDependencyFactory());

 		// load through reflection the dependency and injection processors if running on JDK 1.5 and annotation
 		// processing is enabled
 		if (processAnnotation) {
 			// dependency processor
 			Class<?> annotationProcessor = null;
 			try {
 				annotationProcessor =
 						Class.forName(ANNOTATION_DEPENDENCY_FACTORY, false, ExtenderConfiguration.class
 								.getClassLoader());
 			} catch (ClassNotFoundException cnfe) {
 				log.warn("Gemini Blueprint extensions bundle not present, annotation processing disabled.");
 				log.debug("Gemini Blueprint extensions bundle not present, annotation processing disabled.", cnfe);
 				return;
 			}
 			Object processor = BeanUtils.instantiateClass(annotationProcessor);
 			Assert.isInstanceOf(OsgiServiceDependencyFactory.class, processor);
 			dependencyFactories.add(1, (OsgiServiceDependencyFactory) processor);

 			if (debug)
 				log.debug("Succesfully loaded annotation dependency processor [" + ANNOTATION_DEPENDENCY_FACTORY + "]");

 			// add injection processor (first in line)
 			postProcessors.add(0, new OsgiAnnotationPostProcessor());
 			log.info("Gemini Blueprint extensions annotation processing enabled");
 		} else {
 			if (debug) {
 				log.debug("Gemini Blueprint extensions annotation processing disabled; [" + ANNOTATION_DEPENDENCY_FACTORY
 						+ "] not loaded");
 			}
 		}

 	}

 	private TaskExecutor createDefaultTaskExecutor() {
 		// create thread-pool for starting contexts
 		ThreadGroup threadGroup =
 				new ThreadGroup("eclipse-gemini-blueprint-extender[" + ObjectUtils.getIdentityHexString(this) + "]-threads");
 		threadGroup.setDaemon(false);

 		ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
 		taskExecutor.setMaxPoolSize(Runtime.getRuntime().availableProcessors());
 		taskExecutor.setThreadGroup(threadGroup);
 		taskExecutor.setThreadNamePrefix("EclipseGeminiBlueprintExtenderThread-");
 		taskExecutor.initialize();

 		isTaskExecutorManagedInternally = true;

 		return taskExecutor;
 	}

 	private TaskExecutor createDefaultShutdownTaskExecutor() {
 		ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
 		taskExecutor.setThreadNamePrefix("Gemini Blueprint context shutdown thread ");
 		taskExecutor.setDaemon(true);
 		taskExecutor.setMaxPoolSize(1);
 		taskExecutor.initialize();

 		isShutdownTaskExecutorManagedInternally = true;

 		return taskExecutor;
 	}

 	private OsgiBundleApplicationContextEventMulticaster createDefaultEventMulticaster() {
 		isMulticasterManagedInternally = true;
 		return new OsgiBundleApplicationContextEventMulticasterAdapter(new SimpleApplicationEventMulticaster());
 	}

 	private OsgiBundleApplicationContextListener createDefaultApplicationContextListener() {
 		return new DefaultOsgiBundleApplicationContextListener(log);
 	}

 	private long getShutdownWaitTime(Properties properties) {
 		return Long.parseLong(properties.getProperty(SHUTDOWN_WAIT_KEY));
 	}

     private boolean getShutdownAsynchronously(Properties properties) {
         return Boolean.valueOf(properties.getProperty(SHUTDOWN_ASYNCHRONOUS_KEY));
     }

 	private long getDependencyWaitTime(Properties properties) {
 		return Long.parseLong(properties.getProperty(WAIT_FOR_DEPS_TIMEOUT_KEY));
 	}

 	private boolean getProcessAnnotations(Properties properties) {
 		return Boolean.valueOf(properties.getProperty(PROCESS_ANNOTATIONS_KEY)).booleanValue()
 				|| Boolean.getBoolean(AUTO_ANNOTATION_PROCESSING);
 	}

 	/**
 	 * Returns the taskExecutor.
 	 *
 	 * @return Returns the taskExecutor
 	 */
 	public TaskExecutor getTaskExecutor() {
 		synchronized (lock) {
 			return taskExecutor;
 		}
 	}

 	/**
 	 * Returns the shutdown task executor.
 	 *
 	 * @return Returns the shutdown task executor
 	 */
 	public TaskExecutor getShutdownTaskExecutor() {
 		synchronized (lock) {
 			return shutdownTaskExecutor;
 		}
 	}

 	/**
 	 * Returns the contextEventListener.
 	 *
 	 * @return Returns the contextEventListener
 	 */
 	public OsgiBundleApplicationContextListener getContextEventListener() {
 		synchronized (lock) {
 			return contextEventListener;
 		}
 	}

 	/**
 	 * Returns the shutdownWaitTime.
 	 *
 	 * @return Returns the shutdownWaitTime
 	 */
 	public long getShutdownWaitTime() {
 		synchronized (lock) {
 			return shutdownWaitTime;
 		}
 	}

 	/**
 	 * Indicates if the process annotation is enabled or not.
 	 *
 	 * @return Returns true if the annotation should be processed or not otherwise.
 	 */
 	public boolean shouldProcessAnnotation() {
 		synchronized (lock) {
 			return processAnnotation;
 		}
 	}

     /**
      * @return whether the application context shutdown during the bundle stop phase shall be
      *         performed asynchronously.
      */
     public boolean shouldShutdownAsynchronously() {
         synchronized (lock) {
             return this.shutdownAsynchronously;
         }
     }

 	/**
 	 * Returns the dependencyWaitTime.
 	 *
 	 * @return Returns the dependencyWaitTime
 	 */
 	public long getDependencyWaitTime() {
 		synchronized (lock) {
 			return dependencyWaitTime;
 		}
 	}

 	/**
 	 * Returns the eventMulticaster.
 	 *
 	 * @return Returns the eventMulticaster
 	 */
 	public OsgiBundleApplicationContextEventMulticaster getEventMulticaster() {
 		synchronized (lock) {
 			return eventMulticaster;
 		}
 	}

 	/**
 	 * Sets the flag to force the taskExtender to close up in case of runaway threads - this applies *only* if the
 	 * taskExecutor has been created internally.
 	 *
 	 * <p/> The flag will cause a best attempt to shutdown the threads.
 	 *
 	 * @param forceThreadShutdown The forceThreadShutdown to set.
 	 */
 	public void setForceThreadShutdown(boolean forceThreadShutdown) {
 		synchronized (lock) {
 			this.forceThreadShutdown = forceThreadShutdown;
 		}
 	}

 	/**
 	 * Returns the contextCreator.
 	 *
 	 * @return Returns the contextCreator
 	 */
 	public OsgiApplicationContextCreator getContextCreator() {
 		synchronized (lock) {
 			return contextCreator;
 		}
 	}

 	/**
 	 * Returns the postProcessors.
 	 *
 	 * @return Returns the postProcessors
 	 */
 	public List<OsgiBeanFactoryPostProcessor> getPostProcessors() {
 		return postProcessors;
 	}

 	/**
 	 * Returns the class loader wrapped around the extender bundle.
 	 *
 	 * @return extender bundle class loader
 	 */
 	public ClassLoader getClassLoader() {
 		return classLoader;
 	}

 	/**
 	 * Returns the dependencies factories declared by the extender configuration. The list automatically contains the
 	 * default listeners (such as the annotation one).
 	 *
 	 * @return list of dependency factories
 	 */
 	public List<OsgiServiceDependencyFactory> getDependencyFactories() {
 		return dependencyFactories;
 	}
 }
	/******************************************************************************
	* Copyright (c) 2006, 2010 VMware Inc.
	* All rights reserved. This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License v1.0
	* and Apache License v2.0 which accompanies this distribution.
	* The Eclipse Public License is available at
	* http://www.eclipse.org/legal/epl-v10.html and the Apache License v2.0
	* is available at http://www.opensource.org/licenses/apache2.0.php.
	* You may elect to redistribute this code under either of these licenses.
	*
	* Contributors:
	* VMware Inc.
	*****************************************************************************/

	package org.eclipse.gemini.blueprint.extender.internal.support;

	import org.apache.commons.logging.Log;
	import org.apache.commons.logging.LogFactory;
	import org.eclipse.gemini.blueprint.context.ConfigurableOsgiBundleApplicationContext;
	import org.eclipse.gemini.blueprint.context.event.OsgiBundleApplicationContextEventMulticaster;
	import org.eclipse.gemini.blueprint.context.event.OsgiBundleApplicationContextEventMulticasterAdapter;
	import org.eclipse.gemini.blueprint.context.event.OsgiBundleApplicationContextListener;
	import org.eclipse.gemini.blueprint.context.support.OsgiBundleXmlApplicationContext;
	import org.eclipse.gemini.blueprint.extender.OsgiApplicationContextCreator;
	import org.eclipse.gemini.blueprint.extender.OsgiBeanFactoryPostProcessor;
	import org.eclipse.gemini.blueprint.extender.OsgiServiceDependencyFactory;
	import org.eclipse.gemini.blueprint.extender.internal.dependencies.startup.MandatoryImporterDependencyFactory;
	import org.eclipse.gemini.blueprint.extender.support.internal.ConfigUtils;
	import org.eclipse.gemini.blueprint.util.BundleDelegatingClassLoader;
	import org.osgi.framework.Bundle;
	import org.osgi.framework.BundleActivator;
	import org.osgi.framework.BundleContext;
	import org.springframework.beans.BeanUtils;
	import org.springframework.beans.factory.DisposableBean;
	import org.springframework.context.event.SimpleApplicationEventMulticaster;
	import org.springframework.core.task.TaskExecutor;
	import org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor;
	import org.springframework.util.Assert;
	import org.springframework.util.ObjectUtils;

	import java.io.UnsupportedEncodingException;
	import java.net.URL;
	import java.net.URLDecoder;
	import java.util.*;

	/**
	* Configuration class for the extender. Takes care of locating the extender specific configurations and merging the
	* results with the defaults.
	*
	* @author Costin Leau
	*/
	public class ExtenderConfiguration implements BundleActivator {

	/** logger */
	protected final Log log = LogFactory.getLog(getClass());

	private static final String TASK_EXECUTOR_NAME = "taskExecutor";

	private static final String SHUTDOWN_TASK_EXECUTOR_NAME = "shutdownTaskExecutor";

	private static final String CONTEXT_CREATOR_NAME = "applicationContextCreator";

	private static final String APPLICATION_EVENT_MULTICASTER_BEAN_NAME = "osgiApplicationEventMulticaster";

	private static final String CONTEXT_LISTENER_NAME = "osgiApplicationContextListener";

	private static final String PROPERTIES_NAME = "extenderProperties";

	private static final String SHUTDOWN_ASYNCHRONOUS_KEY = "shutdown.asynchronously";

	private static final String SHUTDOWN_WAIT_KEY = "shutdown.wait.time";

	private static final String PROCESS_ANNOTATIONS_KEY = "process.annotations";

	private static final String WAIT_FOR_DEPS_TIMEOUT_KEY = "dependencies.wait.time";

	private static final String EXTENDER_CFG_LOCATION = "META-INF/spring/extender";

	private static final String XML_PATTERN = "*.xml";

	private static final String ANNOTATION_DEPENDENCY_FACTORY =
	"org.eclipse.gemini.blueprint.extensions.annotation.ServiceReferenceDependencyBeanFactoryPostProcessor";

	/** annotation processing system property (kept for backwards compatibility) */
	private static final String AUTO_ANNOTATION_PROCESSING =
	"org.eclipse.gemini.blueprint.extender.annotation.auto.processing";

	//
	// defaults
	//

	// default dependency wait time (in milliseconds)
	private static final long DEFAULT_DEP_WAIT = ConfigUtils.DIRECTIVE_TIMEOUT_DEFAULT * 1000;
	private static final boolean DEFAULT_NS_BUNDLE_STATE = true;
	private static final boolean DEFAULT_SHUTDOWN_ASYNCHRONOUS = true;
	private static final long DEFAULT_SHUTDOWN_WAIT = 10 * 1000;

	private static final boolean DEFAULT_PROCESS_ANNOTATION = true;

	private ConfigurableOsgiBundleApplicationContext extenderConfiguration;

	private TaskExecutor taskExecutor, shutdownTaskExecutor;

	private boolean isTaskExecutorManagedInternally;

	private boolean isShutdownTaskExecutorManagedInternally;

	private boolean isMulticasterManagedInternally;

	private long shutdownWaitTime, dependencyWaitTime;

	private boolean shutdownAsynchronously;

	private boolean processAnnotation, nsBundledResolved;

	private OsgiBundleApplicationContextEventMulticaster eventMulticaster;

	private OsgiBundleApplicationContextListener contextEventListener;

	private boolean forceThreadShutdown;

	private OsgiApplicationContextCreator contextCreator = null;

	/** bundle wrapped class loader */
	private ClassLoader classLoader;
	/** List of context post processors */
	private final List<OsgiBeanFactoryPostProcessor> postProcessors =
	Collections.synchronizedList(new ArrayList<OsgiBeanFactoryPostProcessor>(0));
	/** List of service dependency factories */
	private final List<OsgiServiceDependencyFactory> dependencyFactories =
	Collections.synchronizedList(new ArrayList<OsgiServiceDependencyFactory>(0));

	// fields reading/writing lock
	private final Object lock = new Object();

	/**
	* Constructs a new <code>ExtenderConfiguration</code> instance. Locates the extender configuration, creates an
	* application context which will returned the extender items.
	*
	* @param extenderBundleContext extender OSGi bundle context
	*/
	public void start(BundleContext extenderBundleContext) {
	Bundle bundle = extenderBundleContext.getBundle();
	Properties properties = new Properties(createDefaultProperties());

	Enumeration<?> enm = bundle.findEntries(EXTENDER_CFG_LOCATION, XML_PATTERN, false);

	if (enm == null) {
	log.info("No custom extender configuration detected; using defaults...");
	synchronized (lock) {
	taskExecutor = createDefaultTaskExecutor();
	shutdownTaskExecutor = createDefaultShutdownTaskExecutor();
	eventMulticaster = createDefaultEventMulticaster();
	contextEventListener = createDefaultApplicationContextListener();
	}
	classLoader = BundleDelegatingClassLoader.createBundleClassLoaderFor(bundle);
	} else {
	String[] configs = copyEnumerationToList(enm);

	log.info("Detected extender custom configurations at " + ObjectUtils.nullSafeToString(configs));
	// create OSGi specific XML context
	ConfigurableOsgiBundleApplicationContext extenderAppCtx = new OsgiBundleXmlApplicationContext(configs);
	extenderAppCtx.setBundleContext(extenderBundleContext);
	extenderAppCtx.refresh();

	synchronized (lock) {
	extenderConfiguration = extenderAppCtx;
	// initialize beans
	taskExecutor =
	extenderConfiguration.containsBean(TASK_EXECUTOR_NAME) ? extenderConfiguration
	.getBean(TASK_EXECUTOR_NAME, TaskExecutor.class) : createDefaultTaskExecutor();

	shutdownTaskExecutor =
	extenderConfiguration.containsBean(SHUTDOWN_TASK_EXECUTOR_NAME) ? extenderConfiguration
	.getBean(SHUTDOWN_TASK_EXECUTOR_NAME, TaskExecutor.class)
	: createDefaultShutdownTaskExecutor();

	eventMulticaster =
	extenderConfiguration.containsBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME) ? extenderConfiguration
	.getBean(APPLICATION_EVENT_MULTICASTER_BEAN_NAME,
	OsgiBundleApplicationContextEventMulticaster.class)
	: createDefaultEventMulticaster();

	contextCreator =
	extenderConfiguration.containsBean(CONTEXT_CREATOR_NAME) ? extenderConfiguration
	.getBean(CONTEXT_CREATOR_NAME, OsgiApplicationContextCreator.class)
	: null;

	contextEventListener =
	extenderConfiguration.containsBean(CONTEXT_LISTENER_NAME) ? extenderConfiguration
	.getBean(CONTEXT_LISTENER_NAME, OsgiBundleApplicationContextListener.class)
	: createDefaultApplicationContextListener();
	}

	// get post processors
	postProcessors.addAll(extenderConfiguration.getBeansOfType(OsgiBeanFactoryPostProcessor.class).values());

	// get dependency factories
	dependencyFactories.addAll(extenderConfiguration.getBeansOfType(OsgiServiceDependencyFactory.class)
	.values());

	classLoader = extenderConfiguration.getClassLoader();
	// extender properties using the defaults as backup
	if (extenderConfiguration.containsBean(PROPERTIES_NAME)) {
	Properties customProperties =
	extenderConfiguration.getBean(PROPERTIES_NAME, Properties.class);
	Enumeration<?> propertyKey = customProperties.propertyNames();
	while (propertyKey.hasMoreElements()) {
	String property = (String) propertyKey.nextElement();
	properties.setProperty(property, customProperties.getProperty(property));
	}
	}
	}

	synchronized (lock) {
	shutdownWaitTime = getShutdownWaitTime(properties);
	shutdownAsynchronously = getShutdownAsynchronously(properties);
	dependencyWaitTime = getDependencyWaitTime(properties);
	processAnnotation = getProcessAnnotations(properties);
	}

	// load default dependency factories
	addDefaultDependencyFactories();

	// allow post processing
	contextCreator = postProcess(contextCreator);
	}

	/**
	* Allows post processing of the context creator.
	*
	* @param contextCreator
	* @return
	*/
	protected OsgiApplicationContextCreator postProcess(OsgiApplicationContextCreator contextCreator) {
	return contextCreator;
	}

	/**
	* {@inheritDoc}
	*
	* Cleanup the configuration items.
	*/
	public void stop(BundleContext extenderBundleContext) {

	synchronized (lock) {
	if (isMulticasterManagedInternally) {
	eventMulticaster.removeAllListeners();
	eventMulticaster = null;
	}

	if (extenderConfiguration != null) {
	extenderConfiguration.close();
	extenderConfiguration = null;
	}

	// postpone the task executor shutdown
	if (forceThreadShutdown) {

	if (isTaskExecutorManagedInternally) {
	log.warn("Forcing the (internally created) taskExecutor to stop...");
	ThreadGroup th = ((ThreadPoolTaskExecutor) taskExecutor).getThreadGroup();
	if (!th.isDestroyed()) {
	// ask the threads nicely to stop
	th.interrupt();
	}
	}
	taskExecutor = null;
	}

	if (isShutdownTaskExecutorManagedInternally) {
	try {
	((DisposableBean) shutdownTaskExecutor).destroy();
	} catch (Exception ex) {
	log.debug("Received exception while shutting down shutdown task executor", ex);
	}
	shutdownTaskExecutor = null;
	}
	}
	}

	/**
	* Copies the URLs returned by the given enumeration and returns them as an array of Strings for consumption by the
	* application context.
	*
	* @param enm
	* @return
	*/
	@SuppressWarnings("deprecation")
	private String[] copyEnumerationToList(Enumeration<?> enm) {
	List<String> urls = new ArrayList<String>(4);
	while (enm != null && enm.hasMoreElements()) {
	URL configURL = (URL) enm.nextElement();
	if (configURL != null) {
	String configURLAsString = configURL.toExternalForm();
	try {
	urls.add(URLDecoder.decode(configURLAsString, "UTF8"));
	} catch (UnsupportedEncodingException uee) {
	log.warn("UTF8 encoding not supported, using the platform default");
	urls.add(URLDecoder.decode(configURLAsString));
	}
	}
	}

	return urls.toArray(new String[urls.size()]);
	}

	private Properties createDefaultProperties() {
	Properties properties = new Properties();
	properties.setProperty(SHUTDOWN_WAIT_KEY, "" + DEFAULT_SHUTDOWN_WAIT);
	properties.setProperty(SHUTDOWN_ASYNCHRONOUS_KEY, "" + DEFAULT_SHUTDOWN_ASYNCHRONOUS);
	properties.setProperty(PROCESS_ANNOTATIONS_KEY, "" + DEFAULT_PROCESS_ANNOTATION);
	properties.setProperty(WAIT_FOR_DEPS_TIMEOUT_KEY, "" + DEFAULT_DEP_WAIT);

	return properties;
	}

	protected void addDefaultDependencyFactories() {
	boolean debug = log.isDebugEnabled();

	// default JDK 1.4 processor
	dependencyFactories.add(0, new MandatoryImporterDependencyFactory());

	// load through reflection the dependency and injection processors if running on JDK 1.5 and annotation
	// processing is enabled
	if (processAnnotation) {
	// dependency processor
	Class<?> annotationProcessor = null;
	try {
	annotationProcessor =
	Class.forName(ANNOTATION_DEPENDENCY_FACTORY, false, ExtenderConfiguration.class
	.getClassLoader());
	} catch (ClassNotFoundException cnfe) {
	log.warn("Gemini Blueprint extensions bundle not present, annotation processing disabled.");
	log.debug("Gemini Blueprint extensions bundle not present, annotation processing disabled.", cnfe);
	return;
	}
	Object processor = BeanUtils.instantiateClass(annotationProcessor);
	Assert.isInstanceOf(OsgiServiceDependencyFactory.class, processor);
	dependencyFactories.add(1, (OsgiServiceDependencyFactory) processor);

	if (debug)
	log.debug("Succesfully loaded annotation dependency processor [" + ANNOTATION_DEPENDENCY_FACTORY + "]");

	// add injection processor (first in line)
	postProcessors.add(0, new OsgiAnnotationPostProcessor());
	log.info("Gemini Blueprint extensions annotation processing enabled");
	} else {
	if (debug) {
	log.debug("Gemini Blueprint extensions annotation processing disabled; [" + ANNOTATION_DEPENDENCY_FACTORY
	+ "] not loaded");
	}
	}

	}

	private TaskExecutor createDefaultTaskExecutor() {
	// create thread-pool for starting contexts
	ThreadGroup threadGroup =
	new ThreadGroup("eclipse-gemini-blueprint-extender[" + ObjectUtils.getIdentityHexString(this) + "]-threads");
	threadGroup.setDaemon(false);

	ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
	taskExecutor.setMaxPoolSize(Runtime.getRuntime().availableProcessors());
	taskExecutor.setThreadGroup(threadGroup);
	taskExecutor.setThreadNamePrefix("EclipseGeminiBlueprintExtenderThread-");
	taskExecutor.initialize();

	isTaskExecutorManagedInternally = true;

	return taskExecutor;
	}

	private TaskExecutor createDefaultShutdownTaskExecutor() {
	ThreadPoolTaskExecutor taskExecutor = new ThreadPoolTaskExecutor();
	taskExecutor.setThreadNamePrefix("Gemini Blueprint context shutdown thread ");
	taskExecutor.setDaemon(true);
	taskExecutor.setMaxPoolSize(1);
	taskExecutor.initialize();

	isShutdownTaskExecutorManagedInternally = true;

	return taskExecutor;
	}

	private OsgiBundleApplicationContextEventMulticaster createDefaultEventMulticaster() {
	isMulticasterManagedInternally = true;
	return new OsgiBundleApplicationContextEventMulticasterAdapter(new SimpleApplicationEventMulticaster());
	}

	private OsgiBundleApplicationContextListener createDefaultApplicationContextListener() {
	return new DefaultOsgiBundleApplicationContextListener(log);
	}

	private long getShutdownWaitTime(Properties properties) {
	return Long.parseLong(properties.getProperty(SHUTDOWN_WAIT_KEY));
	}

	private boolean getShutdownAsynchronously(Properties properties) {
	return Boolean.valueOf(properties.getProperty(SHUTDOWN_ASYNCHRONOUS_KEY));
	}

	private long getDependencyWaitTime(Properties properties) {
	return Long.parseLong(properties.getProperty(WAIT_FOR_DEPS_TIMEOUT_KEY));
	}

	private boolean getProcessAnnotations(Properties properties) {
	return Boolean.valueOf(properties.getProperty(PROCESS_ANNOTATIONS_KEY)).booleanValue()
	\|\| Boolean.getBoolean(AUTO_ANNOTATION_PROCESSING);
	}

	/**
	* Returns the taskExecutor.
	*
	* @return Returns the taskExecutor
	*/
	public TaskExecutor getTaskExecutor() {
	synchronized (lock) {
	return taskExecutor;
	}
	}

	/**
	* Returns the shutdown task executor.
	*
	* @return Returns the shutdown task executor
	*/
	public TaskExecutor getShutdownTaskExecutor() {
	synchronized (lock) {
	return shutdownTaskExecutor;
	}
	}

	/**
	* Returns the contextEventListener.
	*
	* @return Returns the contextEventListener
	*/
	public OsgiBundleApplicationContextListener getContextEventListener() {
	synchronized (lock) {
	return contextEventListener;
	}
	}

	/**
	* Returns the shutdownWaitTime.
	*
	* @return Returns the shutdownWaitTime
	*/
	public long getShutdownWaitTime() {
	synchronized (lock) {
	return shutdownWaitTime;
	}
	}

	/**
	* Indicates if the process annotation is enabled or not.
	*
	* @return Returns true if the annotation should be processed or not otherwise.
	*/
	public boolean shouldProcessAnnotation() {
	synchronized (lock) {
	return processAnnotation;
	}
	}

	/**
	* @return whether the application context shutdown during the bundle stop phase shall be
	* performed asynchronously.
	*/
	public boolean shouldShutdownAsynchronously() {
	synchronized (lock) {
	return this.shutdownAsynchronously;
	}
	}

	/**
	* Returns the dependencyWaitTime.
	*
	* @return Returns the dependencyWaitTime
	*/
	public long getDependencyWaitTime() {
	synchronized (lock) {
	return dependencyWaitTime;
	}
	}

	/**
	* Returns the eventMulticaster.
	*
	* @return Returns the eventMulticaster
	*/
	public OsgiBundleApplicationContextEventMulticaster getEventMulticaster() {
	synchronized (lock) {
	return eventMulticaster;
	}
	}

	/**
	* Sets the flag to force the taskExtender to close up in case of runaway threads - this applies only if the
	* taskExecutor has been created internally.
	*
	* <p/> The flag will cause a best attempt to shutdown the threads.
	*
	* @param forceThreadShutdown The forceThreadShutdown to set.
	*/
	public void setForceThreadShutdown(boolean forceThreadShutdown) {
	synchronized (lock) {
	this.forceThreadShutdown = forceThreadShutdown;
	}
	}

	/**
	* Returns the contextCreator.
	*
	* @return Returns the contextCreator
	*/
	public OsgiApplicationContextCreator getContextCreator() {
	synchronized (lock) {
	return contextCreator;
	}
	}

	/**
	* Returns the postProcessors.
	*
	* @return Returns the postProcessors
	*/
	public List<OsgiBeanFactoryPostProcessor> getPostProcessors() {
	return postProcessors;
	}

	/**
	* Returns the class loader wrapped around the extender bundle.
	*
	* @return extender bundle class loader
	*/
	public ClassLoader getClassLoader() {
	return classLoader;
	}

	/**
	* Returns the dependencies factories declared by the extender configuration. The list automatically contains the
	* default listeners (such as the annotation one).
	*
	* @return list of dependency factories
	*/
	public List<OsgiServiceDependencyFactory> getDependencyFactories() {
	return dependencyFactories;
	}
	}