HSEARCH-3101 Add a way to define named beans from integrations (backe…

…nds, ...)

engine/src/main/java/org/hibernate/search/engine/common/impl/SearchIntegrationBuilderImpl.java

@@ -156,7 +156,7 @@ public SearchIntegration build() {
 				beanResolver = new ReflectionBeanResolver( classResolver );
 			}
 
-			BeanProvider beanProvider = new BeanProviderImpl( beanResolver );
+			BeanProvider beanProvider = new BeanProviderImpl( classResolver, beanResolver );
 			ServiceManager serviceManager = new ServiceManagerImpl( classResolver, resourceResolver, beanProvider );
 			RootBuildContext rootBuildContext = new RootBuildContext( serviceManager, failureCollector );
 

engine/src/main/java/org/hibernate/search/engine/environment/bean/impl/BeanConfigurationContextImpl.java

@@ -0,0 +1,33 @@
+/*
+ * Hibernate Search, full-text search for your domain model
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.search.engine.environment.bean.impl;
+
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+import org.hibernate.search.engine.environment.bean.spi.BeanConfigurationContext;
+import org.hibernate.search.engine.environment.bean.spi.BeanFactory;
+import org.hibernate.search.util.impl.common.Contracts;
+
+final class BeanConfigurationContextImpl implements BeanConfigurationContext {
+
+	private Map<ConfiguredBeanKey<?>, BeanFactory<?>> explicitlyConfiguredBeans = new HashMap<>();
+
+	@Override
+	public <T> void define(Class<T> exposedType, String name, BeanFactory<T> factory) {
+		Contracts.assertNotNull( exposedType, "exposedType" );
+		Contracts.assertNotNull( name, "name" );
+		Contracts.assertNotNull( factory, "factory" );
+		explicitlyConfiguredBeans.put( new ConfiguredBeanKey<>( exposedType, name ), factory );
+	}
+
+	Map<ConfiguredBeanKey<?>, BeanFactory<?>> getConfiguredBeans() {
+		return Collections.unmodifiableMap( explicitlyConfiguredBeans );
+	}
+
+}

engine/src/main/java/org/hibernate/search/engine/environment/bean/impl/BeanCreationContextImpl.java

@@ -0,0 +1,23 @@
+/*
+ * Hibernate Search, full-text search for your domain model
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.search.engine.environment.bean.impl;
+
+import org.hibernate.search.engine.environment.bean.BeanProvider;
+import org.hibernate.search.engine.environment.bean.spi.BeanCreationContext;
+
+final class BeanCreationContextImpl implements BeanCreationContext {
+	private final BeanProvider beanProvider;
+
+	BeanCreationContextImpl(BeanProvider beanProvider) {
+		this.beanProvider = beanProvider;
+	}
+
+	@Override
+	public BeanProvider getBeanProvider() {
+		return beanProvider;
+	}
+}

engine/src/main/java/org/hibernate/search/engine/environment/bean/impl/BeanProviderImpl.java

@@ -7,22 +7,40 @@
 package org.hibernate.search.engine.environment.bean.impl;
 
 import java.lang.invoke.MethodHandles;
+import java.util.Map;
 
 import org.hibernate.search.engine.environment.bean.BeanProvider;
 import org.hibernate.search.engine.environment.bean.BeanReference;
+import org.hibernate.search.engine.environment.bean.spi.BeanConfigurer;
+import org.hibernate.search.engine.environment.bean.spi.BeanCreationContext;
+import org.hibernate.search.engine.environment.bean.spi.BeanFactory;
 import org.hibernate.search.engine.environment.bean.spi.BeanResolver;
+import org.hibernate.search.engine.environment.classpath.spi.ClassResolver;
 import org.hibernate.search.engine.logging.impl.Log;
+import org.hibernate.search.util.SearchException;
 import org.hibernate.search.util.impl.common.LoggerFactory;
 import org.hibernate.search.util.impl.common.StringHelper;
 
-public class BeanProviderImpl implements BeanProvider {
+public final class BeanProviderImpl implements BeanProvider {
 
 	private static final Log log = LoggerFactory.make( Log.class, MethodHandles.lookup() );
 
 	private final BeanResolver beanResolver;
+	private final Map<ConfiguredBeanKey<?>, BeanFactory<?>> explicitlyConfiguredBeans;
 
-	public BeanProviderImpl(BeanResolver beanResolver) {
+	private final BeanCreationContext beanCreationContext;
+
+	public BeanProviderImpl(ClassResolver classResolver, BeanResolver beanResolver) {
 		this.beanResolver = beanResolver;
+
+		// TODO maybe also add a way to pass configurer through a configuration property?
+		BeanConfigurationContextImpl configurationContext = new BeanConfigurationContextImpl();
+		for ( BeanConfigurer beanConfigurer : classResolver.loadJavaServices( BeanConfigurer.class ) ) {
+			beanConfigurer.configure( configurationContext );
+		}
+		this.explicitlyConfiguredBeans = configurationContext.getConfiguredBeans();
+
+		this.beanCreationContext = new BeanCreationContextImpl( this );
 	}
 
 	@Override
@@ -38,7 +56,7 @@ public <T> T getBean(Class<T> expectedClass, String nameReference) {
 		if ( StringHelper.isEmpty( nameReference ) ) {
 			throw log.emptyBeanReferenceNameNullOrEmpty();
 		}
-		return beanResolver.resolve( expectedClass, nameReference );
+		return getBeanFromBeanResolverOrConfiguredBeans( expectedClass, nameReference );
 	}
 
 	@Override
@@ -56,7 +74,8 @@ public <T> T getBean(Class<T> expectedClass, BeanReference reference) {
 			return beanResolver.resolve( expectedClass, nameReference, typeReference );
 		}
 		else if ( nameProvided ) {
-			return beanResolver.resolve( expectedClass, nameReference );
+			// This is the only situation where querying configured beans make sense
+			return getBeanFromBeanResolverOrConfiguredBeans( expectedClass, nameReference );
 		}
 		else if ( typeProvided ) {
 			return beanResolver.resolve( expectedClass, typeReference );
@@ -65,4 +84,41 @@ else if ( typeProvided ) {
 			throw log.emptyBeanReferenceNoNameNoType();
 		}
 	}
+
+	private <T> T getBeanFromBeanResolverOrConfiguredBeans(Class<T> expectedClass, String nameReference) {
+		try {
+			return beanResolver.resolve( expectedClass, nameReference );
+		}
+		catch (SearchException e) {
+			/*
+			 * Fall back to an explicitly configured bean.
+			 * It's important to do this *after* trying the bean resolver,
+			 * so that adding explicitly configured beans in a new version of Hibernate Search
+			 * doesn't break existing user's configuration.
+			 */
+			try {
+				T explicitlyConfiguredBean = getExplicitlyConfiguredBean( expectedClass, nameReference );
+				if ( explicitlyConfiguredBean != null ) {
+					return explicitlyConfiguredBean;
+				}
+			}
+			catch (RuntimeException e2) {
+				e.addSuppressed( e2 );
+			}
+			throw e;
+		}
+	}
+
+	private <T> T getExplicitlyConfiguredBean(Class<T> exposedType, String name) {
+		ConfiguredBeanKey<T> key = new ConfiguredBeanKey<>( exposedType, name );
+		@SuppressWarnings("unchecked") // We know the factory has the correct type, see BeanConfigurationContextImpl
+		BeanFactory<T> factory = (BeanFactory<T>) explicitlyConfiguredBeans.get( key );
+		if ( factory == null ) {
+			return null;
+		}
+		else {
+			return factory.create( beanCreationContext );
+		}
+	}
+
 }

engine/src/main/java/org/hibernate/search/engine/environment/bean/impl/ConfiguredBeanKey.java

@@ -0,0 +1,34 @@
+/*
+ * Hibernate Search, full-text search for your domain model
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.search.engine.environment.bean.impl;
+
+import java.util.Objects;
+
+final class ConfiguredBeanKey<T> {
+	private final Class<T> exposedType;
+	private final String name;
+
+	ConfiguredBeanKey(Class<T> exposedType, String name) {
+		this.exposedType = exposedType;
+		this.name = name;
+	}
+
+	@Override
+	public boolean equals(Object obj) {
+		if ( obj == null || getClass() != obj.getClass() ) {
+			return false;
+		}
+		ConfiguredBeanKey<?> other = (ConfiguredBeanKey<?>) obj;
+		return Objects.equals( exposedType, other.exposedType )
+				&& Objects.equals( name, other.name );
+	}
+
+	@Override
+	public int hashCode() {
+		return Objects.hash( exposedType, name );
+	}
+}

engine/src/main/java/org/hibernate/search/engine/environment/bean/spi/BeanConfigurationContext.java

@@ -0,0 +1,13 @@
+/*
+ * Hibernate Search, full-text search for your domain model
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.search.engine.environment.bean.spi;
+
+public interface BeanConfigurationContext {
+
+	<T> void define(Class<T> exposedType, String name, BeanFactory<T> factory);
+
+}

engine/src/main/java/org/hibernate/search/engine/environment/bean/spi/BeanConfigurer.java

@@ -0,0 +1,17 @@
+/*
+ * Hibernate Search, full-text search for your domain model
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.search.engine.environment.bean.spi;
+
+public interface BeanConfigurer {
+
+	/**
+	 * Configure beans as necessary using the given {@code context}.
+	 * @param context A context exposing methods to configure beans.
+	 */
+	void configure(BeanConfigurationContext context);
+
+}

engine/src/main/java/org/hibernate/search/engine/environment/bean/spi/BeanCreationContext.java

@@ -0,0 +1,15 @@
+/*
+ * Hibernate Search, full-text search for your domain model
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.search.engine.environment.bean.spi;
+
+import org.hibernate.search.engine.environment.bean.BeanProvider;
+
+public interface BeanCreationContext {
+
+	BeanProvider getBeanProvider();
+
+}

engine/src/main/java/org/hibernate/search/engine/environment/bean/spi/BeanFactory.java

@@ -0,0 +1,13 @@
+/*
+ * Hibernate Search, full-text search for your domain model
+ *
+ * License: GNU Lesser General Public License (LGPL), version 2.1 or later
+ * See the lgpl.txt file in the root directory or <http://www.gnu.org/licenses/lgpl-2.1.html>.
+ */
+package org.hibernate.search.engine.environment.bean.spi;
+
+public interface BeanFactory<T> {
+
+	T create(BeanCreationContext context);
+
+}