HHH-8646 use ServiceTracker in OsgiServiceUtil

hibernate-osgi/hibernate-osgi.gradle

@@ -24,6 +24,7 @@ dependencies {
 	// MUST use 4.3.1!  4.3.0 was compiled with "-target jsr14".
 	// http://blog.osgi.org/2012/10/43-companion-code-for-java-7.html
 	compile( "org.osgi:org.osgi.core:4.3.1" )
+	compile( "org.osgi:org.osgi.compendium:4.3.1" )
 	
 	testCompile( libraries.shrinkwrap_api )
 	testCompile( libraries.shrinkwrap )

hibernate-osgi/src/main/java/org/hibernate/osgi/OsgiJtaPlatform.java

@@ -30,7 +30,6 @@ import org.hibernate.TransactionException;
 import org.hibernate.engine.transaction.internal.jta.JtaStatusHelper;
 import org.hibernate.engine.transaction.jta.platform.spi.JtaPlatform;
 import org.osgi.framework.BundleContext;
-import org.osgi.framework.ServiceReference;
 
 /**
  * Offers the JTA Platform provided by the OSGi container. The Enterprise
@@ -55,14 +54,32 @@ public class OsgiJtaPlatform implements JtaPlatform {
 
 	@Override
 	public TransactionManager retrieveTransactionManager() {
-		final ServiceReference sr = bundleContext.getServiceReference( TransactionManager.class.getName() );
+		try {
-		return sr == null ? null : (TransactionManager) bundleContext.getService( sr );
+			final TransactionManager transactionManager = OsgiServiceUtil.getServiceImpl(
+					TransactionManager.class, bundleContext );
+			if (transactionManager == null) {
+				throw new TransactionException("Cannot retrieve the TransactionManager OSGi service!");
+			}
+			return transactionManager;
+		}
+		catch (Exception e) {
+			throw new TransactionException("Cannot retrieve the TransactionManager OSGi service!", e);
+		}
 	}
 
 	@Override
 	public UserTransaction retrieveUserTransaction() {
-		final ServiceReference sr = bundleContext.getServiceReference( UserTransaction.class.getName() );
+		try {
-		return sr == null ? null : (UserTransaction) bundleContext.getService( sr );
+			final UserTransaction userTransaction = OsgiServiceUtil.getServiceImpl(
+					UserTransaction.class, bundleContext );
+			if (userTransaction == null) {
+				throw new TransactionException("Cannot retrieve the UserTransaction OSGi service!");
+			}
+			return userTransaction;
+		}
+		catch (Exception e) {
+			throw new TransactionException("Cannot retrieve the UserTransaction OSGi service!", e);
+		}
 	}
 
 	@Override
@@ -73,7 +90,12 @@ public class OsgiJtaPlatform implements JtaPlatform {
 
 	@Override
 	public boolean canRegisterSynchronization() {
-		return JtaStatusHelper.isActive( retrieveTransactionManager() );
+		try {
+			return JtaStatusHelper.isActive( retrieveTransactionManager() );
+		}
+		catch (Exception e) {
+			return false;
+		}
 	}
 
 	@Override

hibernate-osgi/src/main/java/org/hibernate/osgi/OsgiPersistenceProvider.java

@@ -23,6 +23,7 @@
  */
 package org.hibernate.osgi;
 
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -121,30 +122,30 @@ public class OsgiPersistenceProvider extends HibernatePersistenceProvider {
 
 		settings.put( AvailableSettings.JTA_PLATFORM, osgiJtaPlatform );
 
-		final List<Integrator> integrators = OsgiServiceUtil.getServiceImpls( Integrator.class, context );
+		final Integrator[] integrators = OsgiServiceUtil.getServiceImpls( Integrator.class, context );
 		final IntegratorProvider integratorProvider = new IntegratorProvider() {
 			@Override
 			public List<Integrator> getIntegrators() {
-				return integrators;
+				return Arrays.asList( integrators );
 			}
 		};
 		settings.put( EntityManagerFactoryBuilderImpl.INTEGRATOR_PROVIDER, integratorProvider );
 
-		final List<StrategyRegistrationProvider> strategyRegistrationProviders = OsgiServiceUtil.getServiceImpls(
+		final StrategyRegistrationProvider[] strategyRegistrationProviders = OsgiServiceUtil.getServiceImpls(
 				StrategyRegistrationProvider.class, context );
 		final StrategyRegistrationProviderList strategyRegistrationProviderList = new StrategyRegistrationProviderList() {
 			@Override
 			public List<StrategyRegistrationProvider> getStrategyRegistrationProviders() {
-				return strategyRegistrationProviders;
+				return Arrays.asList( strategyRegistrationProviders );
 			}
 		};
 		settings.put( EntityManagerFactoryBuilderImpl.STRATEGY_REGISTRATION_PROVIDERS, strategyRegistrationProviderList );
 
-		final List<TypeContributor> typeContributors = OsgiServiceUtil.getServiceImpls( TypeContributor.class, context );
+		final TypeContributor[] typeContributors = OsgiServiceUtil.getServiceImpls( TypeContributor.class, context );
 		final TypeContributorList typeContributorList = new TypeContributorList() {
 			@Override
 			public List<TypeContributor> getTypeContributors() {
-				return typeContributors;
+				return Arrays.asList( typeContributors );
 			}
 		};
 		settings.put( EntityManagerFactoryBuilderImpl.TYPE_CONTRIBUTORS, typeContributorList );

hibernate-osgi/src/main/java/org/hibernate/osgi/OsgiServiceUtil.java

@@ -20,13 +20,11 @@
  */
 package org.hibernate.osgi;
 
-import java.util.ArrayList;
+import java.lang.reflect.Array;
-import java.util.Collection;
-import java.util.List;
 
 import org.jboss.logging.Logger;
 import org.osgi.framework.BundleContext;
-import org.osgi.framework.ServiceReference;
+import org.osgi.util.tracker.ServiceTracker;
 
 /**
  * Utilities for dealing with OSGi environments
@@ -37,28 +35,47 @@ public class OsgiServiceUtil {
 	private static final Logger LOG = Logger.getLogger( OsgiServiceUtil.class );
 
 	/**
-	 * Locate all implementors of the given service contract in the given OSGi buindle context
+	 * Locate all implementors of the given service contract in the given OSGi buindle context.  Utilizes
+	 * {@link ServiceTracker} (best practice, automatically handles a lot of boilerplate and error conditions).
 	 *
 	 * @param contract The service contract for which to locate implementors
 	 * @param context The OSGi bundle context
-	 * @param <T> The Java type of the service to locate
+	 * @param T[] The Java type of the service to locate
 	 *
 	 * @return All know implementors
 	 */
-	public static <T> List<T> getServiceImpls(Class<T> contract, BundleContext context) {
+	public static <T> T[] getServiceImpls(Class<T> contract, BundleContext bundleContext) {
-		final List<T> serviceImpls = new ArrayList<T>();
+		final ServiceTracker<T, T> serviceTracker = new ServiceTracker<T, T>( bundleContext, contract, null );
 		try {
-			final Collection<ServiceReference<T>> serviceRefs = context.getServiceReferences( contract, null );
+			T[] services = (T[]) serviceTracker.getServices();
-			for ( ServiceReference<T> serviceRef : serviceRefs ) {
+			if (services != null) {
-				serviceImpls.add( context.getService( serviceRef ) );
+				return services;
 			}
 		}
 		catch ( Exception e ) {
 			LOG.warnf( e, "Exception while discovering OSGi service implementations : %s", contract.getName() );
 		}
-		return serviceImpls;
+		return (T[]) Array.newInstance(contract, 0);
 	}
 
-	private OsgiServiceUtil() {
+	/**
+	 * Locate the single implementor of the given service contract in the given OSGi buindle context.  Utilizes
+	 * {@link ServiceTracker#waitForService(long)}
+	 *
+	 * @param contract The service contract for which to locate implementors
+	 * @param context The OSGi bundle context
+	 * @param T[] The Java type of the service to locate
+	 *
+	 * @return All know implementors
+	 */
+	public static <T> T getServiceImpl(Class<T> contract, BundleContext bundleContext) {
+		final ServiceTracker<T, T> serviceTracker = new ServiceTracker<T, T>( bundleContext, contract, null );
+		try {
+			return (T) serviceTracker.waitForService( 1000 );
+		}
+		catch ( Exception e ) {
+			LOG.warnf( e, "Exception while discovering OSGi service implementations : %s", contract.getName() );
+			return null;
+		}
 	}
 }

hibernate-osgi/src/main/java/org/hibernate/osgi/OsgiSessionFactoryService.java

@@ -21,7 +21,6 @@
 package org.hibernate.osgi;
 
 import java.util.Collection;
-import java.util.List;
 
 import org.hibernate.SessionFactory;
 import org.hibernate.boot.registry.BootstrapServiceRegistryBuilder;
@@ -107,18 +106,18 @@ public class OsgiSessionFactoryService implements ServiceFactory {
 		final BootstrapServiceRegistryBuilder builder = new BootstrapServiceRegistryBuilder();
 		builder.with( osgiClassLoader );
 
-		final List<Integrator> integrators = OsgiServiceUtil.getServiceImpls( Integrator.class, context );
+		final Integrator[] integrators = OsgiServiceUtil.getServiceImpls( Integrator.class, context );
 		for ( Integrator integrator : integrators ) {
 			builder.with( integrator );
 		}
 
-		final List<StrategyRegistrationProvider> strategyRegistrationProviders
+		final StrategyRegistrationProvider[] strategyRegistrationProviders
 				= OsgiServiceUtil.getServiceImpls( StrategyRegistrationProvider.class, context );
 		for ( StrategyRegistrationProvider strategyRegistrationProvider : strategyRegistrationProviders ) {
 			builder.withStrategySelectors( strategyRegistrationProvider );
 		}
         
-		final List<TypeContributor> typeContributors = OsgiServiceUtil.getServiceImpls( TypeContributor.class, context );
+		final TypeContributor[] typeContributors = OsgiServiceUtil.getServiceImpls( TypeContributor.class, context );
 		for ( TypeContributor typeContributor : typeContributors ) {
 			configuration.registerTypeContributor( typeContributor );
 		}