HHH-18194 - Remove @Proxy

Author: sebersole

documentation/src/main/asciidoc/userguide/chapters/domain/entity.adoc

@@ -453,50 +453,6 @@ when executing an HQL or JPQL which selects from the `AccountSummary` entity,
 Hibernate will trigger a Persistence Context flush if there are pending `Account`, `Client` or `AccountTransaction` entity state transitions.
 ====
 
-[[entity-proxy]]
-==== Define a custom entity proxy
-
-By default, when it needs to use a proxy instead of the actual POJO, Hibernate is going to use a Bytecode manipulation library like
-https://bytebuddy.net/[Byte Buddy].
-
-However, if the entity class is final, a proxy will not be created; you will get a POJO even when you only need a proxy reference.
-In this case, you could proxy an interface that this particular entity implements, as illustrated by the following example.
-
-NOTE: Supplying a custom proxy class has been allowed historically, but has never seen much use. Also, setting the `lazy` property to `false`, effectively disallowing proxy creation for an entity type, can easily lead to performance degradation due to the N + 1 query issue. As of 6.2 `@Proxy` has been formally deprecated.
-
-See the <<concrete-proxy,@ConcreteProxy>> paragraph if you wish to resolve the concrete type of proxies for the purpose of `instanceof` checks and typecasts.
-
-[[entity-proxy-interface-mapping]]
-.Final entity class implementing the `Identifiable` interface
-====
-[source,java]
-----
-include::{example-dir-proxy}/ProxyInterfaceTest.java[tag=entity-proxy-interface-mapping,indent=0]
-----
-====
-
-The https://docs.jboss.org/hibernate/orm/{majorMinorVersion}/javadocs/org/hibernate/annotations/Proxy.html[`@Proxy`]
-annotation is used to specify a custom proxy implementation for the current annotated entity.
-
-When loading the `Book` entity proxy, Hibernate is going to proxy the `Identifiable` interface instead as illustrated by the following example:
-
-[[entity-proxy-persist-mapping]]
-.Proxying the final entity class implementing the `Identifiable` interface
-====
-[source,java]
-----
-include::{example-dir-proxy}/ProxyInterfaceTest.java[tag=entity-proxy-persist-mapping,indent=0]
-----
-
-[source,sql]
-----
-include::{extrasdir}/entity/entity-proxy-persist-mapping.sql[]
-----
-====
-
-As you can see in the associated SQL snippet, Hibernate issues no SQL SELECT query since the proxy can be
-constructed without needing to fetch the actual entity POJO.
-
 [[concrete-proxy]]
 ==== Create proxies that resolve their inheritance subtype
 

hibernate-core/src/main/java/org/hibernate/annotations/Proxy.java

@@ -37,7 +37,6 @@
 import org.hibernate.annotations.OnDelete;
 import org.hibernate.annotations.OptimisticLockType;
 import org.hibernate.annotations.OptimisticLocking;
-import org.hibernate.annotations.Proxy;
 import org.hibernate.annotations.QueryCacheLayout;
 import org.hibernate.annotations.RowId;
 import org.hibernate.annotations.SQLDelete;
@@ -1590,27 +1589,9 @@ else if ( "integer".equals( discriminator.getType().getName() ) ) {
 	}
 
 	public void bindProxy() {
-		final Proxy proxy = annotatedClass.getAnnotationUsage( Proxy.class, getSourceModelContext() );
-		if ( proxy != null ) {
-			lazy = proxy.lazy();
-			proxyClass = lazy ? resolveProxyClass( proxy, annotatedClass, getSourceModelContext() ) : null;
-		}
-		else {
-			//needed to allow association lazy loading.
-			lazy = true;
-			proxyClass = annotatedClass;
-		}
-	}
-
-	private static ClassDetails resolveProxyClass(
-			Proxy proxy,
-			ClassDetails annotatedClass,
-			SourceModelBuildingContext sourceModelContext) {
-		final Class<?> explicitProxyClass = proxy.proxyClass();
-		if ( explicitProxyClass == void.class ) {
-			return annotatedClass;
-		}
-		return sourceModelContext.getClassDetailsRegistry().resolveClassDetails( explicitProxyClass.getName() );
+		//needed to allow association lazy loading.
+		lazy = true;
+		proxyClass = annotatedClass;
 	}
 
 	public void bindConcreteProxy() {

hibernate-core/src/main/java/org/hibernate/boot/model/internal/EntityBinder.java

@@ -488,10 +488,6 @@ public interface HibernateAnnotations {
 			PartitionKey.class,
 			PartitionKeyAnnotation.class
 	);
-	OrmAnnotationDescriptor<Proxy,ProxyAnnotation> PROXY = new OrmAnnotationDescriptor<>(
-			Proxy.class,
-			ProxyAnnotation.class
-	);
 	OrmAnnotationDescriptor<PropertyRef,PropertyRefAnnotation> PROPERTY_REF = new OrmAnnotationDescriptor<>(
 			PropertyRef.class,
 			PropertyRefAnnotation.class

hibernate-core/src/main/java/org/hibernate/boot/models/HibernateAnnotations.java

@@ -16,7 +16,6 @@
 import org.hibernate.annotations.DynamicInsert;
 import org.hibernate.annotations.DynamicUpdate;
 import org.hibernate.annotations.Immutable;
-import org.hibernate.annotations.Proxy;
 import org.hibernate.annotations.ResultCheckStyle;
 import org.hibernate.annotations.SQLDelete;
 import org.hibernate.annotations.SQLInsert;
@@ -40,7 +39,6 @@
 import jakarta.persistence.DiscriminatorValue;
 import jakarta.persistence.Entity;
 
-import static org.hibernate.boot.models.categorize.internal.CategorizationHelper.toClassDetails;
 import static org.hibernate.internal.util.StringHelper.EMPTY_STRINGS;
 import static org.hibernate.internal.util.StringHelper.isNotEmpty;
 import static org.hibernate.internal.util.StringHelper.unqualify;
@@ -106,29 +104,9 @@ public EntityTypeMetadataImpl(
 		this.customUpdateMap = extractCustomSql( classDetails, SQLUpdate.class );
 		this.customDeleteMap = extractCustomSql( classDetails, SQLDelete.class );
 
-		//noinspection deprecation
-		final Proxy proxyAnnotation = classDetails.getDirectAnnotationUsage( Proxy.class );
-		if ( proxyAnnotation != null ) {
-			this.isLazy = proxyAnnotation.lazy();
-
-			if ( this.isLazy ) {
-				final ClassDetails proxyClassDetails = toClassDetails( proxyAnnotation.proxyClass(), modelContext.getClassDetailsRegistry() );
-				if ( proxyClassDetails != null ) {
-					this.proxy = proxyClassDetails.getName();
-				}
-				else {
-					this.proxy = null;
-				}
-			}
-			else {
-				this.proxy = null;
-			}
-		}
-		else {
-			// defaults are that it is lazy and that the class itself is the proxy class
-			this.isLazy = true;
-			this.proxy = getEntityName();
-		}
+		// defaults are that it is lazy and that the class itself is the proxy class
+		this.isLazy = true;
+		this.proxy = getEntityName();
 
 		final DiscriminatorValue discriminatorValueAnn = classDetails.getDirectAnnotationUsage( DiscriminatorValue.class );
 		if ( discriminatorValueAnn != null ) {
@@ -175,29 +153,9 @@ public EntityTypeMetadataImpl(
 		this.customUpdateMap = extractCustomSql( classDetails, SQLUpdate.class );
 		this.customDeleteMap = extractCustomSql( classDetails, SQLDelete.class );
 
-		//noinspection deprecation
-		final Proxy proxyAnnotation = classDetails.getDirectAnnotationUsage( Proxy.class );
-		if ( proxyAnnotation != null ) {
-			this.isLazy = proxyAnnotation.lazy();
-
-			if ( this.isLazy ) {
-				final ClassDetails proxyClassDetails = toClassDetails( proxyAnnotation.proxyClass(), modelContext.getClassDetailsRegistry() );
-				if ( proxyClassDetails != null ) {
-					this.proxy = proxyClassDetails.getName();
-				}
-				else {
-					this.proxy = null;
-				}
-			}
-			else {
-				this.proxy = null;
-			}
-		}
-		else {
-			// defaults are that it is lazy and that the class itself is the proxy class
-			this.isLazy = true;
-			this.proxy = getEntityName();
-		}
+		// defaults are that it is lazy and that the class itself is the proxy class
+		this.isLazy = true;
+		this.proxy = getEntityName();
 
 		final DiscriminatorValue discriminatorValueAnn = classDetails.getDirectAnnotationUsage( DiscriminatorValue.class );
 		if ( discriminatorValueAnn != null ) {

hibernate-core/src/main/java/org/hibernate/boot/models/annotations/internal/ProxyAnnotation.java

@@ -228,27 +228,24 @@ public void testType() throws Exception {
 	}
 
 	@Test
-	public void testNonLazy() throws Exception {
-		Session s;
-		Transaction tx;
-		s = openSession();
-		tx = s.beginTransaction();
-		Forest f = new Forest();
-		Tree t = new Tree();
-		t.setName( "Basic one" );
-		s.persist( f );
-		s.persist( t );
-		tx.commit();
-		s.close();
-
-		s = openSession();
-		tx = s.beginTransaction();
-		f = (Forest) s.load( Forest.class, f.getId() );
-		t = (Tree) s.load( Tree.class, t.getId() );
-		assertFalse( "Default should be lazy", Hibernate.isInitialized( f ) );
-		assertTrue( "Tree is not lazy", Hibernate.isInitialized( t ) );
-		tx.commit();
-		s.close();
+	public void testLoading() throws Exception {
+		final Forest created = fromTransaction( (session) -> {
+			Forest f = new Forest();
+			session.persist( f );
+			return f;
+		} );
+
+		// getReference
+		inTransaction( (session) -> {
+			final Forest reference = session.getReference( Forest.class, created.getId() );
+			assertFalse( Hibernate.isInitialized( reference ) );
+		} );
+
+		// find
+		inTransaction( (session) -> {
+			final Forest reference = session.find( Forest.class, created.getId() );
+			assertTrue( Hibernate.isInitialized( reference ) );
+		} );
 	}
 
 	@Test

hibernate-core/src/main/java/org/hibernate/boot/models/categorize/internal/EntityTypeMetadataImpl.java

@@ -7,19 +7,15 @@
 
 //$Id$
 package org.hibernate.orm.test.annotations.entity;
+
 import jakarta.persistence.Entity;
 import jakarta.persistence.GeneratedValue;
 import jakarta.persistence.Id;
 
-import org.hibernate.annotations.Proxy;
-
 /**
- * Non lazy entity
- *
  * @author Emmanuel Bernard
  */
 @Entity
-@Proxy(lazy = false)
 public class Tree {
 	private Integer id;
 	private String name;

hibernate-core/src/test/java/org/hibernate/orm/test/annotations/entity/BasicHibernateAnnotationsTest.java

@@ -7,12 +7,12 @@
 
 //$
 package org.hibernate.orm.test.annotations.idmanytoone;
+
 import java.io.Serializable;
-import jakarta.persistence.Basic;
+
 import jakarta.persistence.CascadeType;
 import jakarta.persistence.Column;
 import jakarta.persistence.Entity;
-import jakarta.persistence.FetchType;
 import jakarta.persistence.Id;
 import jakarta.persistence.IdClass;
 import jakarta.persistence.JoinColumn;
@@ -21,7 +21,6 @@
 
 @Entity
 @Table(name="BasketItems")
-@org.hibernate.annotations.Proxy(lazy=false)
 @IdClass(BasketItemsPK.class)
 public class BasketItems implements Serializable {