test and document behavior of SS.get() when entity not found

gavinking · gavinking · commit cdbb8a023b03 · 2025-05-30T08:14:11.000+02:00
diff --git a/hibernate-core/src/main/java/org/hibernate/StatelessSession.java b/hibernate-core/src/main/java/org/hibernate/StatelessSession.java
@@ -240,7 +240,8 @@ public interface StatelessSession extends SharedSessionContract {
 	 * @param entityName The name of the entity to retrieve
 	 * @param id The id of the entity to retrieve
 	 *
-	 * @return a detached entity instance
+	 * @return a detached entity instance, or null if there
+	 *         is no instance with the given id
 	 */
 	Object get(String entityName, Object id);
 
@@ -250,7 +251,8 @@ public interface StatelessSession extends SharedSessionContract {
 	 * @param entityClass The class of the entity to retrieve
 	 * @param id The id of the entity to retrieve
 	 *
-	 * @return a detached entity instance
+	 * @return a detached entity instance, or null if there
+	 *         is no instance with the given id
 	 */
 	<T> T get(Class<T> entityClass, Object id);
 
@@ -261,7 +263,8 @@ public interface StatelessSession extends SharedSessionContract {
 	 * @param id The id of the entity to retrieve
 	 * @param lockMode The lock mode to apply to the entity
 	 *
-	 * @return a detached entity instance
+	 * @return a detached entity instance, or null if there
+	 *         is no instance with the given id
 	 */
 	Object get(String entityName, Object id, LockMode lockMode);
 
@@ -272,7 +275,8 @@ public interface StatelessSession extends SharedSessionContract {
 	 * @param id The id of the entity to retrieve
 	 * @param lockMode The lock mode to apply to the entity
 	 *
-	 * @return a detached entity instance
+	 * @return a detached entity instance, or null if there
+	 *         is no instance with the given id
 	 */
 	<T> T get(Class<T> entityClass, Object id, LockMode lockMode);
 
@@ -285,7 +289,8 @@ public interface StatelessSession extends SharedSessionContract {
 	 * {@linkplain org.hibernate.graph.GraphSemantic#LOAD load graph}
 	 * @param id The id of the entity to retrieve
 	 *
-	 * @return a detached entity instance
+	 * @return a detached entity instance, or null if there
+	 *         is no instance with the given id
 	 *
 	 * @since 7.0
 	 */
@@ -302,7 +307,8 @@ public interface StatelessSession extends SharedSessionContract {
 	 * @param id The id of the entity to retrieve
 	 * @param lockMode The lock mode to apply to the entity
 	 *
-	 * @return a detached entity instance
+	 * @return a detached entity instance, or null if there
+	 *         is no instance with the given id
 	 *
 	 * @since 7.0
 	 */
@@ -317,7 +323,8 @@ public interface StatelessSession extends SharedSessionContract {
 	 *                      how the graph should be interpreted
 	 * @param id The id of the entity to retrieve
 	 *
-	 * @return a detached entity instance
+	 * @return a detached entity instance, or null if there
+	 *         is no instance with the given id
 	 *
 	 * @since 6.3
 	 */
@@ -334,7 +341,8 @@ public interface StatelessSession extends SharedSessionContract {
 	 * @param id The id of the entity to retrieve
 	 * @param lockMode The lock mode to apply to the entity
 	 *
-	 * @return a detached entity instance
+	 * @return a detached entity instance, or null if there
+	 *         is no instance with the given id
 	 *
 	 * @since 6.3
 	 */
diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/bytecode/enhancement/lazy/proxy/LazyToOnesNoProxyFactoryWithSubclassesStatelessTest.java b/hibernate-core/src/test/java/org/hibernate/orm/test/bytecode/enhancement/lazy/proxy/LazyToOnesNoProxyFactoryWithSubclassesStatelessTest.java
@@ -73,7 +73,7 @@ public void testNewEnhancedProxyAssociation(SessionFactoryScope scope) {
 				session -> {
 					final Statistics stats = scope.getSessionFactory().getStatistics();
 					stats.clear();
-					final OtherEntity otherEntity = (OtherEntity) session.get( OtherEntity.class, "test1" );
+					final OtherEntity otherEntity = session.get( OtherEntity.class, "test1" );
 					assertTrue( Hibernate.isPropertyInitialized( otherEntity, "human" ) );
 					assertFalse( Hibernate.isInitialized( otherEntity.human ) );
 					assertFalse( HibernateProxy.class.isInstance( otherEntity.animal ) );
@@ -102,7 +102,7 @@ public void testExistingInitializedAssociationLeafSubclass(SessionFactoryScope s
 		scope.inStatelessSession(
 				session -> {
 
-					final OtherEntity otherEntity = (OtherEntity) session.get( OtherEntity.class, "test1" );
+					final OtherEntity otherEntity = session.get( OtherEntity.class, "test1" );
 					assertTrue( Hibernate.isPropertyInitialized( otherEntity, "animal" ) );
 					/*
 						The original test used
@@ -161,7 +161,7 @@ public void testExistingEnhancedProxyAssociationLeafSubclassOnly(SessionFactoryS
 					final Statistics stats = scope.getSessionFactory().getStatistics();
 					stats.clear();
 
-					final OtherEntity otherEntity = (OtherEntity) session.get( OtherEntity.class, "test1" );
+					final OtherEntity otherEntity = session.get( OtherEntity.class, "test1" );
 					assertNull( otherEntity.animal );
 					assertNull( otherEntity.primate );
 					assertTrue( Hibernate.isPropertyInitialized( otherEntity, "human" ) );
diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/stateless/StatelessSessionTest.java b/hibernate-core/src/test/java/org/hibernate/orm/test/stateless/StatelessSessionTest.java
@@ -8,8 +8,8 @@
 import jakarta.persistence.criteria.CriteriaBuilder;
 import jakarta.persistence.criteria.CriteriaQuery;
 
+import org.hibernate.LockMode;
 import org.hibernate.ScrollMode;
-import org.hibernate.ScrollableResults;
 import org.hibernate.Transaction;
 
 import org.hibernate.testing.orm.junit.DomainModel;
@@ -21,6 +21,7 @@
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertNotNull;
 import static org.junit.jupiter.api.Assertions.assertNotSame;
+import static org.junit.jupiter.api.Assertions.assertNull;
 
 /**
  * @author Gavin King
@@ -33,10 +34,7 @@ public class StatelessSessionTest {
 
 	@AfterEach
 	public void tearDown(SessionFactoryScope scope){
-		scope.inTransaction(
-				session ->
-						session.createQuery( "delete from Document" ).executeUpdate()
-		);
+		scope.getSessionFactory().getSchemaManager().truncate();
 	}
 
 	@Test
@@ -73,7 +71,7 @@ public void testCreateUpdateReadDelete(SessionFactoryScope scope) {
 						assertEquals( "Blahs", doc2.getName() );
 						assertEquals( doc.getText(), doc2.getText() );
 
-						try (ScrollableResults sr = statelessSession.createQuery( "from Document where text is not null" )
+						try (var sr = statelessSession.createQuery( "from Document where text is not null" )
 								.scroll( ScrollMode.FORWARD_ONLY )) {
 							sr.next();
 							doc2 = (Document) sr.get();
@@ -98,9 +96,9 @@ public void testCreateUpdateReadDelete(SessionFactoryScope scope) {
 						criteria = criteriaBuilder.createQuery( Document.class );
 						criteria.from( Document.class );
 
-						try (ScrollableResults sr = statelessSession.createQuery( criteria ).scroll( ScrollMode.FORWARD_ONLY )) {
+						try (var sr = statelessSession.createQuery( criteria ).scroll( ScrollMode.FORWARD_ONLY )) {
 							sr.next();
-							doc2 = (Document) sr.get();
+							doc2 = sr.get();
 						}
 						assertEquals( "Blahs", doc2.getName() );
 						assertEquals( doc.getText(), doc2.getText() );
@@ -118,6 +116,20 @@ public void testCreateUpdateReadDelete(SessionFactoryScope scope) {
 				} );
 	}
 
+	@Test
+	public void testGetNull(SessionFactoryScope scope) {
+		scope.inStatelessSession(
+				statelessSession -> {
+					assertNull( statelessSession.get( Document.class, "Blank" ) );
+				}
+		);
+		scope.inStatelessTransaction(
+				statelessSession -> {
+					assertNull( statelessSession.get( Document.class, "Blank", LockMode.PESSIMISTIC_WRITE ) );
+				}
+		);
+	}
+
 	@Test
 	public void testHqlBulk(SessionFactoryScope scope) {
 		scope.inStatelessSession(
diff --git a/hibernate-core/src/test/java/org/hibernate/orm/test/stateless/UpsertVersionedTest.java b/hibernate-core/src/test/java/org/hibernate/orm/test/stateless/UpsertVersionedTest.java
@@ -12,7 +12,7 @@
 import org.hibernate.testing.orm.junit.SessionFactoryScope;
 import org.junit.jupiter.api.Test;
 
-import static org.junit.Assert.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
 
 @SessionFactory
 @DomainModel(annotatedClasses = UpsertVersionedTest.Record.class)
@@ -23,22 +23,22 @@ public class UpsertVersionedTest {
 			s.upsert(new Record(456L,2L,"hello mars"));
 		});
 		scope.inStatelessTransaction(s-> {
-			assertEquals("hello earth",s.get(Record.class,123L).message);
-			assertEquals("hello mars",s.get(Record.class,456L).message);
+			assertEquals( "hello earth", s.get( Record.class,123L).message );
+			assertEquals( "hello mars", s.get( Record.class,456L).message );
 		});
 		scope.inStatelessTransaction(s-> {
 			s.upsert(new Record(123L,0L,"goodbye earth"));
 		});
 		scope.inStatelessTransaction(s-> {
-			assertEquals("goodbye earth",s.get(Record.class,123L).message);
-			assertEquals("hello mars",s.get(Record.class,456L).message);
+			assertEquals( "goodbye earth", s.get( Record.class,123L).message );
+			assertEquals( "hello mars", s.get( Record.class,456L).message );
 		});
 		scope.inStatelessTransaction(s-> {
 			s.upsert(new Record(456L,3L,"goodbye mars"));
 		});
 		scope.inStatelessTransaction(s-> {
-			assertEquals("goodbye earth",s.get(Record.class,123L).message);
-			assertEquals("goodbye mars",s.get(Record.class,456L).message);
+			assertEquals( "goodbye earth", s.get( Record.class,123L).message );
+			assertEquals( "goodbye mars", s.get( Record.class,456L).message );
 		});
 	}
 	@Entity(name = "Record")
