HHH-7555 - Add ability to query revision entity instances of an entity class without instantiating the entity instances.

(backport from wip/6.0)

hibernate-envers/src/main/java/org/hibernate/envers/query/AuditQueryCreator.java

@@ -6,6 +6,7 @@
  */
 package org.hibernate.envers.query;
 
+import org.hibernate.Incubating;
 import org.hibernate.envers.boot.internal.EnversService;
 import org.hibernate.envers.exception.NotAuditedException;
 import org.hibernate.envers.internal.reader.AuditReaderImplementor;
@@ -171,7 +172,8 @@ public class AuditQueryCreator {
 				auditReaderImplementor,
 				c,
 				selectEntitiesOnly,
-				selectDeletedEntities
+				selectDeletedEntities,
+				false
 		);
 	}
 
@@ -211,7 +213,60 @@ public class AuditQueryCreator {
 				c,
 				entityName,
 				selectEntitiesOnly,
-				selectDeletedEntities
+				selectDeletedEntities,
+				false
+		);
+	}
+
+	/**
+	 * Creates a query that selects the revision entities associated with the specified entity.  You may also
+	 * specify whether the revision entities list should include those for deletions of the entity class.
+	 *
+	 * @param clazz Class of the entities for which to query.
+	 * @param selectDeletedEntities If true, the result will include revision entities where deletions occurred.
+	 *
+	 * @return A query of revision entities based on the specified entity class.  The results of the query will
+	 * 		   be stored in ascending order by the revision number unless an order is specified.
+	 *
+	 * @since 5.3
+	 */
+	@Incubating
+	public AuditQuery forRevisionsOfEntity(Class<?> clazz, boolean selectDeletedEntities) {
+		clazz = getTargetClassIfProxied( clazz );
+		return new RevisionsOfEntityQuery(
+				enversService,
+				auditReaderImplementor,
+				clazz,
+				false,
+				selectDeletedEntities,
+				true
+		);
+	}
+
+	/**
+	 * Creates a query that selects the revision entities associated with the specified entity.  You may also
+	 * specify whether the revision entities list should include those for deletions of the entity class.
+	 *
+	 * @param clazz Class of the entities for which to query.
+	 * @param entityName Name of the entity (for cases where it cannot be guessed based on class clazz).
+	 * @param selectDeletedEntities If true, the result will include revision entities where deletions occurred.
+	 *
+	 * @return A query of revision entities based on the specified entity class.  The results of the query will
+	 * 		   be stored in ascending order by the revision number unless an order is specified.
+	 *
+	 * @since 5.3
+	 */
+	@Incubating
+	public AuditQuery forRevisionsOfEntity(Class<?> clazz, String entityName, boolean selectDeletedEntities) {
+		clazz = getTargetClassIfProxied( clazz );
+		return new RevisionsOfEntityQuery(
+				enversService,
+				auditReaderImplementor,
+				clazz,
+				entityName,
+				false,
+				selectDeletedEntities,
+				true
 		);
 	}
 

hibernate-envers/src/main/java/org/hibernate/envers/query/internal/impl/AbstractAuditQuery.java

@@ -21,6 +21,7 @@ import org.hibernate.LockMode;
 import org.hibernate.LockOptions;
 import org.hibernate.envers.boot.internal.EnversService;
 import org.hibernate.envers.exception.AuditException;
+import org.hibernate.envers.exception.NotAuditedException;
 import org.hibernate.envers.internal.entities.EntityInstantiator;
 import org.hibernate.envers.internal.reader.AuditReaderImplementor;
 import org.hibernate.envers.internal.tools.query.QueryBuilder;
@@ -79,6 +80,9 @@ public abstract class AbstractAuditQuery implements AuditQueryImplementor {
 		entityClassName = cls.getName();
 		this.entityName = entityName;
 		versionsEntityName = enversService.getAuditEntitiesConfiguration().getAuditEntityName( entityName );
+		if ( !enversService.getEntitiesConfigurations().isVersioned( entityName ) ) {
+			throw new NotAuditedException( entityName, "Entity [" + entityName + "] is not versioned" );
+		}
 		aliasToEntityNameMap.put( REFERENCED_ENTITY_ALIAS, entityName );
 
 		qb = new QueryBuilder( versionsEntityName, REFERENCED_ENTITY_ALIAS );

hibernate-envers/src/main/java/org/hibernate/envers/query/internal/impl/RevisionsOfEntityQuery.java

@@ -9,6 +9,7 @@ package org.hibernate.envers.query.internal.impl;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
+import java.util.stream.Collectors;
 
 import javax.persistence.criteria.JoinType;
 
@@ -30,17 +31,20 @@ import org.hibernate.proxy.HibernateProxy;
 public class RevisionsOfEntityQuery extends AbstractAuditQuery {
 	private final boolean selectEntitiesOnly;
 	private final boolean selectDeletedEntities;
+	private final boolean selectRevisionInfoOnly;
 
 	public RevisionsOfEntityQuery(
 			EnversService enversService,
 			AuditReaderImplementor versionsReader,
 			Class<?> cls,
 			boolean selectEntitiesOnly,
-			boolean selectDeletedEntities) {
+			boolean selectDeletedEntities,
+			boolean selectRevisionInfoOnly) {
 		super( enversService, versionsReader, cls );
 
 		this.selectEntitiesOnly = selectEntitiesOnly;
 		this.selectDeletedEntities = selectDeletedEntities;
+		this.selectRevisionInfoOnly = selectRevisionInfoOnly && !selectEntitiesOnly;
 	}
 
 	public RevisionsOfEntityQuery(
@@ -48,11 +52,13 @@ public class RevisionsOfEntityQuery extends AbstractAuditQuery {
 			AuditReaderImplementor versionsReader,
 			Class<?> cls, String entityName,
 			boolean selectEntitiesOnly,
-			boolean selectDeletedEntities) {
+			boolean selectDeletedEntities,
+			boolean selectRevisionInfoOnly) {
 		super( enversService, versionsReader, cls, entityName );
 
 		this.selectEntitiesOnly = selectEntitiesOnly;
 		this.selectDeletedEntities = selectDeletedEntities;
+		this.selectRevisionInfoOnly = selectRevisionInfoOnly && !selectEntitiesOnly;
 	}
 
 	private Number getRevisionNumber(Map versionsEntity) {
@@ -121,6 +127,9 @@ public class RevisionsOfEntityQuery extends AbstractAuditQuery {
 		if ( hasProjection() ) {
 			return queryResult;
 		}
+		else if ( selectRevisionInfoOnly ) {
+			return queryResult.stream().map( e -> ( (Object[]) e )[1] ).collect( Collectors.toList() );
+		}
 		else {
 			List entities = new ArrayList();
 			String revisionTypePropertyName = verEntCfg.getRevisionTypePropName();

hibernate-envers/src/test/java/org/hibernate/envers/test/integration/auditReader/AuditReaderAPITest.java

@@ -7,14 +7,23 @@
 package org.hibernate.envers.test.integration.auditReader;
 
 import java.util.Arrays;
+import java.util.List;
+
 import javax.persistence.EntityManager;
 
+import org.hibernate.envers.enhanced.SequenceIdRevisionEntity;
 import org.hibernate.envers.exception.NotAuditedException;
 import org.hibernate.envers.test.BaseEnversJPAFunctionalTestCase;
 import org.hibernate.envers.test.Priority;
 
+import org.hibernate.testing.TestForIssue;
 import org.junit.Test;
 
+import static org.hibernate.testing.junit4.ExtraAssertions.assertTyping;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
+
 /**
  * A test which checks the correct behavior of AuditReader.isEntityClassAudited(Class entityClass).
  *
@@ -45,13 +54,17 @@ public class AuditReaderAPITest extends BaseEnversJPAFunctionalTestCase {
 		ent1.setStr1( "str2" );
 		ent2.setStr1( "str2" );
 		em.getTransaction().commit();
+
+		em.getTransaction().begin();
+		ent1 = em.find( AuditedTestEntity.class, 1 );
+		em.remove( ent1 );
+		em.getTransaction().commit();
 	}
 
 	@Test
 	public void testIsEntityClassAuditedForAuditedEntity() {
-		assert getAuditReader().isEntityClassAudited( AuditedTestEntity.class );
+		assertTrue( getAuditReader().isEntityClassAudited( AuditedTestEntity.class ) );
-
+		assertEquals( Arrays.asList( 1, 2, 3 ), getAuditReader().getRevisions( AuditedTestEntity.class, 1 ) );
-		assert Arrays.asList( 1, 2 ).equals( getAuditReader().getRevisions( AuditedTestEntity.class, 1 ) );
 	}
 
 	@Test
@@ -68,5 +81,37 @@ public class AuditReaderAPITest extends BaseEnversJPAFunctionalTestCase {
 		}
 	}
 
+	@Test
+	@TestForIssue( jiraKey = "HHH-7555" )
+	public void testFindRevisionEntitiesWithoutDeletions() {
+		List<?> revisionInfos = getAuditReader().createQuery()
+				.forRevisionsOfEntity( AuditedTestEntity.class, false )
+				.getResultList();
+		assertEquals( 2, revisionInfos.size() );
+		revisionInfos.forEach( e -> assertTyping( SequenceIdRevisionEntity.class, e ) );
+	}
 
+	@Test
+	@TestForIssue( jiraKey = "HHH-7555" )
+	public void testFindRevisionEntitiesWithDeletions() {
+		List<?> revisionInfos = getAuditReader().createQuery()
+				.forRevisionsOfEntity( AuditedTestEntity.class, true )
+				.getResultList();
+		assertEquals( 3, revisionInfos.size() );
+		revisionInfos.forEach( e -> assertTyping( SequenceIdRevisionEntity.class, e ) );
+	}
+
+	@Test
+	@TestForIssue( jiraKey = "HHH-7555" )
+	public void testFindRevisionEntitiesNonAuditedEntity() {
+		try {
+			List<?> revisionInfos = getAuditReader().createQuery()
+					.forRevisionsOfEntity( NotAuditedTestEntity.class, false )
+					.getResultList();
+			fail( "Expected a NotAuditedException" );
+		}
+		catch ( NotAuditedException e ) {
+			// expected
+		}
+	}
 }