HHH-18815 @Generated should not imply @Immutable

Signed-off-by: Gavin King <gavin@hibernate.org>

hibernate-core/src/main/java/org/hibernate/generator/Assigned.java

@@ -34,6 +34,11 @@ public class Assigned implements Generator {
 		return true;
 	}
 
+	@Override
+	public boolean allowMutation() {
+		return true;
+	}
+
 	@Override
 	public EnumSet<EventType> getEventTypes() {
 		return EventTypeSets.NONE;

hibernate-core/src/main/java/org/hibernate/tuple/entity/CompositeGeneratorBuilder.java

@@ -70,16 +70,7 @@ class CompositeGeneratorBuilder {
 			return createCompositeOnExecutionGenerator();
 		}
 		else {
-			return new Generator() {
+			return DummyGenerator.INSTANCE;
-				@Override
-				public EnumSet<EventType> getEventTypes() {
-					return NONE;
-				}
-				@Override
-				public boolean generatedOnExecution() {
-					return false;
-				}
-			};
 		}
 	}
 
@@ -89,6 +80,8 @@ class CompositeGeneratorBuilder {
 		// the base-line values for the aggregated OnExecutionGenerator we will build here.
 		final EnumSet<EventType> eventTypes = EnumSet.noneOf(EventType.class);
 		boolean referenceColumns = false;
+		boolean writable = false;
+		boolean mutable = false;
 		final String[] columnValues = new String[composite.getColumnSpan()];
 
 		// start building the aggregate values
@@ -120,31 +113,16 @@ class CompositeGeneratorBuilder {
 					columnIndex += span;
 				}
 			}
+			if ( generator.writePropertyValue() ) {
+				writable = true;
+			}
+			if ( generator.allowMutation() ) {
+				mutable = true;
+			}
 		}
-		final boolean referenceColumnsInSql = referenceColumns;
 
 		// then use the aggregated values to build an OnExecutionGenerator
-		return new OnExecutionGenerator() {
+		return new CompositeOnExecutionGenerator( eventTypes, referenceColumns, columnValues, writable, mutable );
-			@Override
-			public EnumSet<EventType> getEventTypes() {
-				return eventTypes;
-			}
-
-			@Override
-			public boolean referenceColumnsInSql(Dialect dialect) {
-				return referenceColumnsInSql;
-			}
-
-			@Override
-			public String[] getReferencedColumnValues(Dialect dialect) {
-				return columnValues;
-			}
-
-			@Override
-			public boolean writePropertyValue() {
-				return false;
-			}
-		};
 	}
 
 	private BeforeExecutionGenerator createCompositeBeforeExecutionGenerator() {
@@ -157,19 +135,54 @@ class CompositeGeneratorBuilder {
 				eventTypes.addAll( generator.getEventTypes() );
 			}
 		}
-		return new BeforeExecutionGenerator() {
+		return new CompositeBeforeExecutionGenerator( entityName, generators, mappingProperty, properties, eventTypes );
+	}
+
+	private record CompositeOnExecutionGenerator(
+			EnumSet<EventType> eventTypes,
+			boolean referenceColumnsInSql,
+			String[] columnValues,
+			boolean writePropertyValue,
+			boolean allowMutation)
+				implements OnExecutionGenerator {
+		@Override
+		public boolean referenceColumnsInSql(Dialect dialect) {
+			return referenceColumnsInSql;
+		}
+		@Override
+		public String[] getReferencedColumnValues(Dialect dialect) {
+			return columnValues;
+		}
+
+		@Override
+		public EnumSet<EventType> getEventTypes() {
+			return eventTypes;
+		}
+	}
+
+	private record CompositeBeforeExecutionGenerator(
+			String entityName,
+			List<Generator> generators,
+			Property mappingProperty,
+			List<Property> properties,
+			EnumSet<EventType> eventTypes)
+				implements BeforeExecutionGenerator {
+		@Override
+		public EnumSet<EventType> getEventTypes() {
+			return eventTypes;
+		}
 		@Override
 		public Object generate(SharedSessionContractImplementor session, Object owner, Object currentValue, EventType eventType) {
 			final EntityPersister persister = session.getEntityPersister( entityName, owner );
 			final int index = persister.getPropertyIndex( mappingProperty.getName() );
 			final EmbeddableMappingType descriptor =
-						persister.getAttributeMapping(index).asEmbeddedAttributeMapping()
+					persister.getAttributeMapping( index ).asEmbeddedAttributeMapping()
 							.getEmbeddableTypeDescriptor();
 			final int size = properties.size();
 			if ( currentValue == null ) {
 				final Object[] generatedValues = new Object[size];
 				for ( int i = 0; i < size; i++ ) {
-						final Generator generator = generators.get(i);
+					final Generator generator = generators.get( i );
 					if ( generator != null ) {
 						generatedValues[i] = ((BeforeExecutionGenerator) generator)
 								.generate( session, owner, null, eventType );
@@ -180,7 +193,7 @@ class CompositeGeneratorBuilder {
 			}
 			else {
 				for ( int i = 0; i < size; i++ ) {
-						final Generator generator = generators.get(i);
+					final Generator generator = generators.get( i );
 					if ( generator != null ) {
 						final Object value = descriptor.getValue( currentValue, i );
 						final Object generatedValue = ((BeforeExecutionGenerator) generator)
@@ -191,11 +204,29 @@ class CompositeGeneratorBuilder {
 				return currentValue;
 			}
 		}
+	}
+
+	private record DummyGenerator() implements Generator {
+		private static final Generator INSTANCE = new DummyGenerator();
 
 		@Override
 		public EnumSet<EventType> getEventTypes() {
-				return eventTypes;
+			return NONE;
+		}
+
+		@Override
+		public boolean generatedOnExecution() {
+			return false;
+		}
+
+		@Override
+		public boolean allowMutation() {
+			return true;
+		}
+
+		@Override
+		public boolean allowAssignedIdentifiers() {
+			return true;
 		}
-		};
 	}
 }

hibernate-core/src/main/java/org/hibernate/tuple/entity/EntityMetamodel.java

@@ -235,9 +235,9 @@ public class EntityMetamodel implements Serializable {
 		boolean foundUpdateableNaturalIdProperty = false;
 		BeforeExecutionGenerator tempVersionGenerator = null;
 
-		List<Property> props = persistentClass.getPropertyClosure();
+		final List<Property> props = persistentClass.getPropertyClosure();
 		for ( int i=0; i<props.size(); i++ ) {
-			Property property = props.get(i);
+			final Property property = props.get(i);
 			final NonIdentifierAttribute attribute;
 			if ( property == persistentClass.getVersion() ) {
 				tempVersionProperty = i;
@@ -310,9 +310,11 @@ public class EntityMetamodel implements Serializable {
 			// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
 			// generated value strategies ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
 			final Generator generator = buildGenerator( name, property, creationContext );
 			if ( generator != null ) {
-				if ( i == tempVersionProperty && !generator.generatedOnExecution() ) {
+				final boolean generatedOnExecution = generator.generatedOnExecution();
+				if ( i == tempVersionProperty && !generatedOnExecution ) {
 					// when we have an in-memory generator for the version, we
 					// want to plug it in to the older infrastructure specific
 					// to version generation, instead of treating it like a
@@ -321,33 +323,33 @@ public class EntityMetamodel implements Serializable {
 				}
 				else {
 					generators[i] = generator;
-					if ( !generator.allowMutation() ) {
+					final boolean allowMutation = generator.allowMutation();
-						propertyInsertability[i] = false;
+					if ( !allowMutation ) {
-						propertyUpdateability[i] = false;
+						propertyCheckability[i] = false;
 					}
 					if ( generator.generatesOnInsert() ) {
-						propertyInsertability[i] = !generatedWithNoParameter( generator );
+						if ( generatedOnExecution ) {
-						if ( generator.generatedOnExecution() ) {
+							propertyInsertability[i] = writePropertyValue( (OnExecutionGenerator) generator );
-							foundPostInsertGeneratedValues = true;
-							if ( generator instanceof BeforeExecutionGenerator ) {
-								foundPreInsertGeneratedValues = true;
 						}
+						foundPostInsertGeneratedValues = foundPostInsertGeneratedValues
+								|| generator instanceof OnExecutionGenerator;
+						foundPreInsertGeneratedValues = foundPreInsertGeneratedValues
+								|| generator instanceof BeforeExecutionGenerator;
 					}
-						else {
+					else if ( !allowMutation ) {
-							foundPreInsertGeneratedValues = true;
+						propertyInsertability[i] = false;
-						}
 					}
 					if ( generator.generatesOnUpdate() ) {
-						propertyUpdateability[i] = !generatedWithNoParameter( generator );
+						if ( generatedOnExecution ) {
-						if ( generator.generatedOnExecution() ) {
+							propertyUpdateability[i] = writePropertyValue( (OnExecutionGenerator) generator );
-							foundPostUpdateGeneratedValues = true;
-							if ( generator instanceof BeforeExecutionGenerator ) {
-								foundPreUpdateGeneratedValues = true;
 						}
+						foundPostUpdateGeneratedValues = foundPostUpdateGeneratedValues
+								|| generator instanceof OnExecutionGenerator;
+						foundPreUpdateGeneratedValues = foundPreUpdateGeneratedValues
+								|| generator instanceof BeforeExecutionGenerator;
 					}
-						else {
+					else if ( !allowMutation ) {
-							foundPreUpdateGeneratedValues = true;
+						propertyUpdateability[i] = false;
-						}
 					}
 				}
 			}
@@ -472,6 +474,15 @@ public class EntityMetamodel implements Serializable {
 //		entityNameByInheritanceClassMap = toSmallMap( entityNameByInheritanceClassMapLocal );
 	}
 
+	private static boolean writePropertyValue(OnExecutionGenerator generator) {
+		final boolean writePropertyValue = generator.writePropertyValue();
+		// TODO: move this validation somewhere else!
+//		if ( !writePropertyValue && generator instanceof BeforeExecutionGenerator ) {
+//			throw new HibernateException( "BeforeExecutionGenerator returned false from OnExecutionGenerator.writePropertyValue()" );
+//		}
+		return writePropertyValue;
+	}
+
 	private Generator buildIdGenerator(PersistentClass persistentClass, RuntimeModelCreationContext creationContext) {
 		final Generator existing = creationContext.getGenerators().get( rootName );
 		if ( existing != null ) {
@@ -513,11 +524,6 @@ public class EntityMetamodel implements Serializable {
 		return getName() + "." + property.getName();
 	}
 
-	private static boolean generatedWithNoParameter(Generator generator) {
-		return generator.generatedOnExecution()
-			&& !((OnExecutionGenerator) generator).writePropertyValue();
-	}
-
 	private static Generator buildGenerator(
 			final String entityName,
 			final Property mappingProperty,

hibernate-core/src/test/java/org/hibernate/orm/test/customsql/CustomSqlOverrideTest.java

@@ -11,6 +11,7 @@ import jakarta.persistence.Id;
 import jakarta.persistence.Table;
 import org.hibernate.annotations.DialectOverride;
 import org.hibernate.annotations.Generated;
+import org.hibernate.annotations.Immutable;
 import org.hibernate.annotations.SQLInsert;
 import org.hibernate.annotations.SQLUpdate;
 import org.hibernate.dialect.H2Dialect;
@@ -82,7 +83,7 @@ public class CustomSqlOverrideTest {
 	static class Custom {
 		@Id @GeneratedValue(strategy = GenerationType.IDENTITY)
 		Long id;
-		@Generated
+		@Generated @Immutable
 		String uid;
 		String whatever;
 	}

hibernate-core/src/test/java/org/hibernate/orm/test/mapping/generated/sqldefault/DefaultTest.java

@@ -44,13 +44,13 @@ public class DefaultTest {
 			assertEquals( unitPrice, entity.unitPrice );
 			assertEquals( 5, entity.quantity );
 			assertEquals( "new", entity.status );
-			entity.status = "old"; //should be ignored when fetch=true
+			entity.status = "old";
 		} );
 		scope.inTransaction( session -> {
 			OrderLine entity = session.createQuery("from WithDefault", OrderLine.class ).getSingleResult();
 			assertEquals( unitPrice, entity.unitPrice );
 			assertEquals( 5, entity.quantity );
-			assertEquals( "new", entity.status );
+			assertEquals( "old", entity.status );
 		} );
 	}
 

hibernate-core/src/test/java/org/hibernate/orm/test/mapping/generated/sqldefault/ImmutableDefaultTest.java

@@ -0,0 +1,77 @@
+/*
+ * SPDX-License-Identifier: LGPL-2.1-or-later
+ * Copyright Red Hat Inc. and Hibernate Authors
+ */
+package org.hibernate.orm.test.mapping.generated.sqldefault;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import org.hibernate.annotations.ColumnDefault;
+import org.hibernate.annotations.Generated;
+import org.hibernate.annotations.Immutable;
+import org.hibernate.testing.orm.junit.DomainModel;
+import org.hibernate.testing.orm.junit.SessionFactory;
+import org.hibernate.testing.orm.junit.SessionFactoryScope;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.Test;
+
+import java.math.BigDecimal;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author Gavin King
+ */
+@SuppressWarnings("JUnitMalformedDeclaration")
+@DomainModel(annotatedClasses = ImmutableDefaultTest.OrderLine.class)
+@SessionFactory
+public class ImmutableDefaultTest {
+
+	@Test
+	public void test(SessionFactoryScope scope) {
+		BigDecimal unitPrice = new BigDecimal("12.99");
+		scope.inTransaction( session -> {
+			OrderLine entity = new OrderLine( unitPrice, 5 );
+			session.persist(entity);
+			session.flush();
+			assertEquals( "new", entity.status );
+			assertEquals( unitPrice, entity.unitPrice );
+			assertEquals( 5, entity.quantity );
+		} );
+		scope.inTransaction( session -> {
+			OrderLine entity = session.createQuery("from WithDefault", OrderLine.class ).getSingleResult();
+			assertEquals( unitPrice, entity.unitPrice );
+			assertEquals( 5, entity.quantity );
+			assertEquals( "new", entity.status );
+			entity.status = "old"; //should be ignored due to @Immutable
+		} );
+		scope.inTransaction( session -> {
+			OrderLine entity = session.createQuery("from WithDefault", OrderLine.class ).getSingleResult();
+			assertEquals( unitPrice, entity.unitPrice );
+			assertEquals( 5, entity.quantity );
+			assertEquals( "new", entity.status );
+		} );
+	}
+
+	@AfterEach
+	public void dropTestData(SessionFactoryScope scope) {
+		scope.inTransaction( session -> session.createQuery( "delete WithDefault" ).executeUpdate() );
+	}
+
+	@Entity(name="WithDefault")
+	public static class OrderLine {
+		@Id
+		private BigDecimal unitPrice;
+		@Id @ColumnDefault(value = "1")
+		private int quantity;
+		@Generated @Immutable
+		@ColumnDefault(value = "'new'")
+		private String status;
+
+		public OrderLine() {}
+		public OrderLine(BigDecimal unitPrice, int quantity) {
+			this.unitPrice = unitPrice;
+			this.quantity = quantity;
+		}
+	}
+}

hibernate-core/src/test/java/org/hibernate/orm/test/mapping/generated/sqldefault/OverriddenDefaultTest.java

@@ -52,7 +52,7 @@ public class OverriddenDefaultTest {
 			OrderLine entity = session.createQuery("from WithDefault", OrderLine.class ).getSingleResult();
 			assertEquals( unitPrice, entity.unitPrice );
 			assertEquals( 5, entity.quantity );
-			assertEquals( getDefault(scope), entity.status );
+			assertEquals( "old", entity.status );
 		} );
 	}