HHH-13614 Allow the IntegratorProvider to be supplied via its FQN in the JPA persistence.xml

hibernate-core/src/main/java/org/hibernate/jpa/boot/internal/EntityManagerFactoryBuilderImpl.java

@@ -276,37 +276,11 @@ public class EntityManagerFactoryBuilderImpl implements EntityManagerFactoryBuil
 			return;
 		}
 
-		MetadataBuilderContributor metadataBuilderContributor = null;
-		Class<? extends MetadataBuilderContributor> metadataBuilderContributorImplClass = null;
-
-		if ( metadataBuilderContributorSetting instanceof MetadataBuilderContributor ) {
-			metadataBuilderContributor = (MetadataBuilderContributor) metadataBuilderContributorSetting;
-		}
-		else if ( metadataBuilderContributorSetting instanceof Class ) {
-			metadataBuilderContributorImplClass = (Class<? extends MetadataBuilderContributor>) metadataBuilderContributorSetting;
-		}
-		else if ( metadataBuilderContributorSetting instanceof String ) {
-			final ClassLoaderService classLoaderService = standardServiceRegistry.getService( ClassLoaderService.class );
-
-			metadataBuilderContributorImplClass = classLoaderService.classForName( (String) metadataBuilderContributorSetting );
-		}
-		else {
-			throw new IllegalArgumentException(
-					"The provided " + METADATA_BUILDER_CONTRIBUTOR + " setting value [" + metadataBuilderContributorSetting + "] is not supported!"
+		MetadataBuilderContributor metadataBuilderContributor = loadSettingInstance(
+				METADATA_BUILDER_CONTRIBUTOR,
+				metadataBuilderContributorSetting,
+				MetadataBuilderContributor.class
 		);
-		}
-
-		if ( metadataBuilderContributorImplClass != null ) {
-			try {
-				metadataBuilderContributor = metadataBuilderContributorImplClass.newInstance();
-			}
-			catch (InstantiationException | IllegalAccessException e) {
-				throw new IllegalArgumentException(
-						"The MetadataBuilderContributor class [" + metadataBuilderContributorImplClass + "] could not be instantiated!",
-						e
-				);
-			}
-		}
 
 		if ( metadataBuilderContributor != null ) {
 			metadataBuilderContributor.contribute( metamodelBuilder );
@@ -394,7 +368,12 @@ public class EntityManagerFactoryBuilderImpl implements EntityManagerFactoryBuil
 			ClassLoaderService providedClassLoaderService) {
 		final BootstrapServiceRegistryBuilder bsrBuilder = new BootstrapServiceRegistryBuilder();
 
-		final IntegratorProvider integratorProvider = (IntegratorProvider) integrationSettings.get( INTEGRATOR_PROVIDER );
+		final IntegratorProvider integratorProvider = loadSettingInstance(
+				INTEGRATOR_PROVIDER,
+				integrationSettings.get( INTEGRATOR_PROVIDER ),
+				IntegratorProvider.class
+		);
+
 		if ( integratorProvider != null ) {
 			for ( Integrator integrator : integratorProvider.getIntegrators() ) {
 				bsrBuilder.applyIntegrator( integrator );
@@ -1394,4 +1373,55 @@ public class EntityManagerFactoryBuilderImpl implements EntityManagerFactoryBuil
 			this.cacheRegionDefinitions.add( cacheRegionDefinition );
 		}
 	}
+
+	private <T> T loadSettingInstance(String settingName, Object settingValue, Class<T> clazz) {
+		if ( settingValue == null ) {
+			return null;
+		}
+
+		T instance = null;
+		Class<? extends T> instanceClass = null;
+
+		if ( clazz.isAssignableFrom( settingValue.getClass() ) ) {
+			instance = (T) settingValue;
+		}
+		else if ( settingValue instanceof Class ) {
+			instanceClass = (Class<? extends T>) settingValue;
+		}
+		else if ( settingValue instanceof String ) {
+			String settingStringValue = (String) settingValue;
+			if ( standardServiceRegistry != null ) {
+				final ClassLoaderService classLoaderService = standardServiceRegistry.getService( ClassLoaderService.class );
+
+				instanceClass = classLoaderService.classForName( settingStringValue );
+			}
+			else {
+				try {
+					instanceClass = (Class<? extends T>) Class.forName( settingStringValue );
+				}
+				catch (ClassNotFoundException e) {
+					throw new IllegalArgumentException( "Can't load class: " + settingStringValue, e );
+				}
+			}
+		}
+		else {
+			throw new IllegalArgumentException(
+				"The provided " + settingName + " setting value [" + settingValue + "] is not supported!"
+			);
+		}
+
+		if ( instanceClass != null ) {
+			try {
+				instance = instanceClass.newInstance();
+			}
+			catch (InstantiationException | IllegalAccessException e) {
+				throw new IllegalArgumentException(
+						"The MetadataBuilderContributor class [" + instanceClass + "] could not be instantiated!",
+						e
+				);
+			}
+		}
+
+		return instance;
+	}
 }

hibernate-core/src/test/java/org/hibernate/jpa/test/query/ConstructorResultDtoTest.java

@@ -0,0 +1,139 @@
+/*
+ * Hibernate, Relational Persistence for Idiomatic Java
+ *
+ * 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.jpa.test.query;
+
+import java.util.*;
+import javax.persistence.*;
+
+import org.hibernate.FlushMode;
+import org.hibernate.Session;
+import org.hibernate.boot.Metadata;
+import org.hibernate.dialect.Oracle8iDialect;
+import org.hibernate.engine.spi.SessionFactoryImplementor;
+import org.hibernate.integrator.spi.Integrator;
+import org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl;
+import org.hibernate.jpa.boot.spi.IntegratorProvider;
+import org.hibernate.jpa.test.BaseEntityManagerFunctionalTestCase;
+
+import org.hibernate.service.spi.SessionFactoryServiceRegistry;
+import org.hibernate.testing.SkipForDialect;
+import org.junit.Test;
+
+import static org.hibernate.testing.junit4.ExtraAssertions.assertTyping;
+import static org.hibernate.testing.transaction.TransactionUtil.doInJPA;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * @author Vlad Mihalcea
+ */
+public class ConstructorResultDtoTest extends BaseEntityManagerFunctionalTestCase {
+
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class<?>[]{
+			Person.class
+		};
+	}
+
+	@Test
+	public void test() {
+		doInJPA(this::entityManagerFactory, entityManager -> {
+			List<PersonDto> dtos = entityManager.createQuery(
+                "select new PersonDto(id, name) " +
+                "from Person", PersonDto.class)
+            .getResultList();
+		});
+	}
+
+    @Override
+    protected void addMappings(Map settings) {
+        settings.put(EntityManagerFactoryBuilderImpl.INTEGRATOR_PROVIDER, DtoIntegratorProvider.class.getName());
+    }
+
+    public static class DtoIntegratorProvider implements IntegratorProvider {
+		@Override
+		public List<Integrator> getIntegrators() {
+			return Collections.singletonList(
+					new Integrator() {
+						@Override
+						public void integrate(Metadata metadata, SessionFactoryImplementor sessionFactory, SessionFactoryServiceRegistry serviceRegistry) {
+							metadata.getImports().put("PersonDto", PersonDto.class.getName());
+						}
+
+						@Override
+						public void disintegrate(SessionFactoryImplementor sessionFactory, SessionFactoryServiceRegistry serviceRegistry) {
+
+						}
+					}
+			);
+		}
+	}
+
+    @Entity(name = "Person")
+	public static class Person {
+
+		@Id
+		@GeneratedValue
+		private Long id;
+
+		private String name;
+
+		private int age;
+
+		public Person() {
+		}
+
+		public Person(String name) {
+			this.name = name;
+		}
+
+		public Long getId() {
+			return id;
+		}
+
+		public String getName() {
+			return name;
+		}
+
+		public int getAge() {
+			return age;
+		}
+
+		public void setAge(int age) {
+			this.age = age;
+		}
+	}
+
+	public static class PersonDto {
+
+		private Long id;
+
+		private String name;
+
+		public PersonDto(Long id, String name) {
+			this.id = id;
+			this.name = name;
+		}
+
+		public void setId(Long id) {
+			this.id = id;
+		}
+
+		public void setName(String name) {
+			this.name = name;
+		}
+
+		public Long getId() {
+			return id;
+		}
+
+		public String getName() {
+			return name;
+		}
+	}
+}