HHH-13020 - When proxying an entity having a private default constructor, the log message is not very clear about the problem

hibernate-core/src/main/java/org/hibernate/internal/CoreMessageLogger.java

@@ -476,6 +476,9 @@ public interface CoreMessageLogger extends BasicLogger {
 	@Message(value = "Bytecode enhancement failed: %s", id = 142)
 	String bytecodeEnhancementFailed(String entityName);
 
+	@Message(value = "Bytecode enhancement failed because no public, protected or package-private default constructor was found for entity: %s. Private constructors don't work with runtime proxies!", id = 143)
+	String bytecodeEnhancementFailedBecauseOfDefaultConstructor(String entityName);
+
 	@LogMessage(level = WARN)
 	@Message(value = "%s = false breaks the EJB3 specification", id = 144)
 	void jdbcAutoCommitFalseBreaksEjb3Spec(String autocommit);

hibernate-core/src/main/java/org/hibernate/proxy/pojo/bytebuddy/ByteBuddyProxyFactory.java

@@ -6,14 +6,11 @@
  */
 package org.hibernate.proxy.pojo.bytebuddy;
 
-import static org.hibernate.internal.CoreLogging.messageLogger;
-
 import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.util.Set;
 
 import org.hibernate.HibernateException;
-import org.hibernate.cfg.Environment;
 import org.hibernate.engine.spi.SharedSessionContractImplementor;
 import org.hibernate.internal.CoreMessageLogger;
 import org.hibernate.internal.util.ReflectHelper;
@@ -23,6 +20,8 @@ import org.hibernate.proxy.ProxyConfiguration;
 import org.hibernate.proxy.ProxyFactory;
 import org.hibernate.type.CompositeType;
 
+import static org.hibernate.internal.CoreLogging.messageLogger;
+
 public class ByteBuddyProxyFactory implements ProxyFactory, Serializable {
 
 	private static final CoreMessageLogger LOG = messageLogger( ByteBuddyProxyFactory.class );
@@ -87,14 +86,20 @@ public class ByteBuddyProxyFactory implements ProxyFactory, Serializable {
 		);
 
 		try {
-			final HibernateProxy proxy = (HibernateProxy) proxyClass.newInstance();
+			final HibernateProxy proxy = (HibernateProxy) proxyClass.getConstructor().newInstance();
 			( (ProxyConfiguration) proxy ).$$_hibernate_set_interceptor( interceptor );
 
 			return proxy;
 		}
+		catch (NoSuchMethodException e) {
+			String logMessage = LOG.bytecodeEnhancementFailedBecauseOfDefaultConstructor( entityName );
+			LOG.error( logMessage, e );
+			throw new HibernateException( logMessage, e );
+		}
 		catch (Throwable t) {
-			LOG.error( LOG.bytecodeEnhancementFailed( entityName ), t );
+			String logMessage = LOG.bytecodeEnhancementFailed( entityName );
-			throw new HibernateException( LOG.bytecodeEnhancementFailed( entityName ), t );
+			LOG.error( logMessage, t );
+			throw new HibernateException( logMessage, t );
 		}
 	}
 }

hibernate-core/src/main/java/org/hibernate/proxy/pojo/javassist/JavassistProxyFactory.java

@@ -122,15 +122,21 @@ public class JavassistProxyFactory implements ProxyFactory, Serializable {
 		);
 
 		try {
-			final HibernateProxy proxy = (HibernateProxy) proxyClass.newInstance();
+			final HibernateProxy proxy = (HibernateProxy) proxyClass.getConstructor().newInstance();
 			( (Proxy) proxy ).setHandler( initializer );
 			initializer.constructed();
 
 			return proxy;
 		}
+		catch (NoSuchMethodException e) {
+			String logMessage = LOG.bytecodeEnhancementFailedBecauseOfDefaultConstructor( entityName );
+			LOG.error( logMessage, e );
+			throw new HibernateException( logMessage, e );
+		}
 		catch (Throwable t) {
-			LOG.error( LOG.bytecodeEnhancementFailed( entityName ), t );
+			String logMessage = LOG.bytecodeEnhancementFailed( entityName );
-			throw new HibernateException( LOG.bytecodeEnhancementFailed( entityName ), t );
+			LOG.error( logMessage, t );
+			throw new HibernateException( logMessage, t );
 		}
 	}
 

hibernate-core/src/test/java/org/hibernate/jpa/test/callbacks/PrivateConstructorTest.java

@@ -0,0 +1,160 @@
+/*
+ * 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.callbacks;
+
+import javax.persistence.CascadeType;
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.EntityManager;
+import javax.persistence.EntityTransaction;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.ManyToOne;
+
+import org.hibernate.internal.CoreMessageLogger;
+import org.hibernate.internal.SessionImpl;
+import org.hibernate.jpa.test.BaseEntityManagerFunctionalTestCase;
+import org.hibernate.proxy.pojo.bytebuddy.ByteBuddyProxyFactory;
+
+import org.hibernate.testing.TestForIssue;
+import org.hibernate.testing.logger.LoggerInspectionRule;
+import org.hibernate.testing.logger.Triggerable;
+import org.hibernate.testing.util.ExceptionUtil;
+import org.junit.Rule;
+import org.junit.Test;
+
+import org.jboss.logging.Logger;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+
+@TestForIssue( jiraKey = "HHH-13020" )
+public class PrivateConstructorTest extends BaseEntityManagerFunctionalTestCase {
+
+	@Rule
+	public LoggerInspectionRule logInspection = new LoggerInspectionRule( Logger.getMessageLogger( CoreMessageLogger.class, ByteBuddyProxyFactory.class.getName() ) );
+
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class<?>[] {
+				Parent.class,
+				Child.class
+		};
+	}
+
+	@Test
+	public void test() {
+		Child child = new Child();
+
+		EntityManager entityManager = null;
+		EntityTransaction txn = null;
+		try {
+			entityManager = createEntityManager();
+			txn = entityManager.getTransaction();
+			txn.begin();
+			entityManager.persist( child );
+			txn.commit();
+
+			entityManager.clear();
+
+			Integer childId = child.getId();
+
+			Triggerable triggerable = logInspection.watchForLogMessages( "HHH000143:" );
+
+			Child childReference = entityManager.getReference( Child.class, childId );
+			try {
+				assertEquals( child.getParent().getName(), childReference.getParent().getName() );
+			}
+			catch (Exception expected) {
+				assertEquals( NoSuchMethodException.class, ExceptionUtil.rootCause( expected ).getClass() );
+				assertTrue( expected.getMessage().contains(
+					"Bytecode enhancement failed because no public, protected or package-private default constructor was found for entity"
+				) );
+			}
+			assertTrue( triggerable.wasTriggered() );
+		}
+		catch (Throwable e) {
+			if ( txn != null && txn.isActive() ) {
+				txn.rollback();
+			}
+			throw e;
+		}
+		finally {
+			if ( entityManager != null ) {
+				entityManager.close();
+			}
+		}
+	}
+
+	@Entity(name = "Parent")
+	public static class Parent {
+
+		private Integer id;
+		private String name;
+
+		private Parent() {
+			name = "Empty";
+		}
+
+		public Parent(String s) {
+			this.name = s;
+		}
+
+		@Id
+		@Column(name = "id")
+		@GeneratedValue(strategy = GenerationType.AUTO)
+		public Integer getId() {
+			return id;
+		}
+
+		public void setId(Integer id) {
+			this.id = id;
+		}
+
+		public String getName() {
+			return name;
+		}
+
+		public void setName(String name) {
+			this.name = name;
+		}
+	}
+
+
+	@Entity(name = "Child")
+	public static class Child {
+
+		private Integer id;
+		private Parent parent;
+
+		public Child() {
+			this.parent = new Parent( "Name" );
+		}
+
+		@Id
+		@Column(name = "id")
+		@GeneratedValue(strategy = GenerationType.AUTO)
+		public Integer getId() {
+			return id;
+		}
+
+		public void setId(Integer id) {
+			this.id = id;
+		}
+
+		@ManyToOne(cascade = { CascadeType.PERSIST, CascadeType.MERGE }, fetch = FetchType.LAZY)
+		public Parent getParent() {
+			return parent;
+		}
+
+		public void setParent(Parent parent) {
+			this.parent = parent;
+		}
+	}
+}

hibernate-core/src/test/java/org/hibernate/jpa/test/callbacks/ProtectedConstructorTest.java

@@ -0,0 +1,136 @@
+/*
+ * 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.callbacks;
+
+import javax.persistence.CascadeType;
+import javax.persistence.Column;
+import javax.persistence.Entity;
+import javax.persistence.EntityManager;
+import javax.persistence.EntityTransaction;
+import javax.persistence.FetchType;
+import javax.persistence.GeneratedValue;
+import javax.persistence.GenerationType;
+import javax.persistence.Id;
+import javax.persistence.ManyToOne;
+
+import org.hibernate.jpa.test.BaseEntityManagerFunctionalTestCase;
+
+import org.hibernate.testing.TestForIssue;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+@TestForIssue( jiraKey = "HHH-13020" )
+public class ProtectedConstructorTest extends BaseEntityManagerFunctionalTestCase {
+
+	@Override
+	protected Class<?>[] getAnnotatedClasses() {
+		return new Class<?>[] {
+				Parent.class,
+				Child.class
+		};
+	}
+
+	@Test
+	public void test() {
+		Child child = new Child();
+
+		EntityManager entityManager = null;
+		EntityTransaction txn = null;
+		try {
+			entityManager = createEntityManager();
+			txn = entityManager.getTransaction();
+			txn.begin();
+			entityManager.persist( child );
+			txn.commit();
+
+			entityManager.clear();
+
+			Integer childId = child.getId();
+
+			Child childReference = entityManager.getReference( Child.class, childId );
+			assertEquals( child.getParent().getName(), childReference.getParent().getName() );
+		}
+		catch (Throwable e) {
+			if ( txn != null && txn.isActive() ) {
+				txn.rollback();
+			}
+			throw e;
+		}
+		finally {
+			if ( entityManager != null ) {
+				entityManager.close();
+			}
+		}
+	}
+
+	@Entity(name = "Parent")
+	public static class Parent {
+
+		private Integer id;
+		private String name;
+
+		protected Parent() {
+			name = "Empty";
+		}
+
+		public Parent(String s) {
+			this.name = s;
+		}
+
+		@Id
+		@Column(name = "id")
+		@GeneratedValue(strategy = GenerationType.AUTO)
+		public Integer getId() {
+			return id;
+		}
+
+		public void setId(Integer id) {
+			this.id = id;
+		}
+
+		public String getName() {
+			return name;
+		}
+
+		public void setName(String name) {
+			this.name = name;
+		}
+	}
+
+
+	@Entity(name = "Child")
+	public static class Child {
+
+		private Integer id;
+		private Parent parent;
+
+		public Child() {
+			this.parent = new Parent( "Name" );
+		}
+
+		@Id
+		@Column(name = "id")
+		@GeneratedValue(strategy = GenerationType.AUTO)
+		public Integer getId() {
+			return id;
+		}
+
+		public void setId(Integer id) {
+			this.id = id;
+		}
+
+		@ManyToOne(cascade = { CascadeType.PERSIST, CascadeType.MERGE }, fetch = FetchType.LAZY)
+		public Parent getParent() {
+			return parent;
+		}
+
+		public void setParent(Parent parent) {
+			this.parent = parent;
+		}
+	}
+}