Allow for customizing the Hibernate MetadataSources instance

Issue: SPR-13710

spring-orm-hibernate5/src/main/java/org/springframework/orm/hibernate5/LocalSessionFactoryBean.java

@@ -23,8 +23,10 @@ import javax.sql.DataSource;
 
 import org.hibernate.Interceptor;
 import org.hibernate.SessionFactory;
+import org.hibernate.boot.MetadataSources;
 import org.hibernate.boot.model.naming.ImplicitNamingStrategy;
 import org.hibernate.boot.model.naming.PhysicalNamingStrategy;
+import org.hibernate.boot.registry.BootstrapServiceRegistryBuilder;
 import org.hibernate.cfg.Configuration;
 import org.hibernate.context.spi.CurrentTenantIdentifierResolver;
 
@@ -40,6 +42,7 @@ import org.springframework.core.io.support.ResourcePatternResolver;
 import org.springframework.core.io.support.ResourcePatternUtils;
 import org.springframework.core.task.AsyncTaskExecutor;
 import org.springframework.core.type.filter.TypeFilter;
+import org.springframework.util.Assert;
 
 /**
  * {@link FactoryBean} that creates a Hibernate
@@ -96,7 +99,9 @@ public class LocalSessionFactoryBean extends HibernateExceptionTranslator
 
 	private AsyncTaskExecutor bootstrapExecutor;
 
-	private ResourcePatternResolver resourcePatternResolver = new PathMatchingResourcePatternResolver();
+	private MetadataSources metadataSources;
+
+	private ResourcePatternResolver resourcePatternResolver;
 
 	private Configuration configuration;
 
@@ -318,15 +323,58 @@ public class LocalSessionFactoryBean extends HibernateExceptionTranslator
 		this.bootstrapExecutor = bootstrapExecutor;
 	}
 
+	/**
+	 * Specify a Hibernate {@link MetadataSources} service to use (e.g. reusing an
+	 * existing one), potentially populated with a custom Hibernate bootstrap
+	 * {@link org.hibernate.service.ServiceRegistry} as well.
+	 * @since 4.3
+	 */
+	public void setMetadataSources(MetadataSources metadataSources) {
+		Assert.notNull(metadataSources, "MetadataSources must not be null");
+		this.metadataSources = metadataSources;
+	}
+
+	/**
+	 * Determine the Hibernate {@link MetadataSources} to use.
+	 * <p>Can also be externally called to initialize and pre-populate a {@link MetadataSources}
+	 * instance which is then going to be used for {@link SessionFactory} building.
+	 * @return the MetadataSources to use (never {@code null})
+	 * @since 4.3
+	 * @see LocalSessionFactoryBuilder#LocalSessionFactoryBuilder(DataSource, ResourceLoader, MetadataSources)
+	 */
+	public MetadataSources getMetadataSources() {
+		if (this.metadataSources == null) {
+			this.metadataSources = new MetadataSources(new BootstrapServiceRegistryBuilder().build());
+		}
+		return this.metadataSources;
+	}
+
+	/**
+	 * Specify a Spring {@link ResourceLoader} to use for Hibernate metadata.
+	 * @param resourceLoader the ResourceLoader to use (never {@code null})
+	 */
 	@Override
 	public void setResourceLoader(ResourceLoader resourceLoader) {
 		this.resourcePatternResolver = ResourcePatternUtils.getResourcePatternResolver(resourceLoader);
 	}
 
+	/**
+	 * Determine the Spring {@link ResourceLoader} to use for Hibernate metadata.
+	 * @return the ResourceLoader to use (never {@code null})
+	 * @since 4.3
+	 */
+	public ResourceLoader getResourceLoader() {
+		if (this.resourcePatternResolver == null) {
+			this.resourcePatternResolver = new PathMatchingResourcePatternResolver();
+		}
+		return this.resourcePatternResolver;
+	}
+
 
 	@Override
 	public void afterPropertiesSet() throws IOException {
-		LocalSessionFactoryBuilder sfb = new LocalSessionFactoryBuilder(this.dataSource, this.resourcePatternResolver);
+		LocalSessionFactoryBuilder sfb = new LocalSessionFactoryBuilder(
+				this.dataSource, getResourceLoader(), getMetadataSources());
 
 		if (this.configLocations != null) {
 			for (Resource resource : this.configLocations) {

spring-orm-hibernate5/src/main/java/org/springframework/orm/hibernate5/LocalSessionFactoryBuilder.java

@@ -38,6 +38,8 @@ import javax.transaction.TransactionManager;
 import org.hibernate.HibernateException;
 import org.hibernate.MappingException;
 import org.hibernate.SessionFactory;
+import org.hibernate.boot.MetadataSources;
+import org.hibernate.boot.registry.BootstrapServiceRegistryBuilder;
 import org.hibernate.cfg.AvailableSettings;
 import org.hibernate.cfg.Configuration;
 import org.hibernate.cfg.Environment;
@@ -116,6 +118,20 @@ public class LocalSessionFactoryBuilder extends Configuration {
 	 * @param resourceLoader the ResourceLoader to load application classes from
 	 */
 	public LocalSessionFactoryBuilder(DataSource dataSource, ResourceLoader resourceLoader) {
+		this(dataSource, resourceLoader, new MetadataSources(new BootstrapServiceRegistryBuilder().build()));
+	}
+
+	/**
+	 * Create a new LocalSessionFactoryBuilder for the given DataSource.
+	 * @param dataSource the JDBC DataSource that the resulting Hibernate SessionFactory should be using
+	 * (may be {@code null})
+	 * @param resourceLoader the ResourceLoader to load application classes from
+	 * @param metadataSources the Hibernate MetadataSources service to use (e.g. reusing an existing one)
+	 * @since 4.3
+	 */
+	public LocalSessionFactoryBuilder(DataSource dataSource, ResourceLoader resourceLoader, MetadataSources metadataSources) {
+		super(metadataSources);
+
 		getProperties().put(Environment.CURRENT_SESSION_CONTEXT_CLASS, SpringSessionContext.class.getName());
 		if (dataSource != null) {
 			getProperties().put(Environment.DATASOURCE, dataSource);
@@ -298,6 +314,7 @@ public class LocalSessionFactoryBuilder extends Configuration {
 	/**
 	 * Proxy invocation handler for background bootstrapping, only enforcing
 	 * a fully initialized target {@code SessionFactory} when actually needed.
+	 * @since 4.3
 	 */
 	private class BootstrapSessionFactoryInvocationHandler implements InvocationHandler {