@

fix: support Java records as JPA @IdClass

createPrimaryKeyInstance() assumed the primary key class could be
built via a no-arg constructor followed by field reflection. Records
have neither a no-arg constructor nor writable fields. Detect a record
pkClass and build it via RecordInstantiationPolicy and its canonical
constructor.
@

Author: hantsy

foundation/org.eclipse.persistence.core/src/main/java/org/eclipse/persistence/descriptors/CMPPolicy.java

@@ -27,6 +27,7 @@
 import org.eclipse.persistence.exceptions.DescriptorException;
 import org.eclipse.persistence.exceptions.ValidationException;
 import org.eclipse.persistence.internal.descriptors.ObjectBuilder;
+import org.eclipse.persistence.internal.descriptors.RecordInstantiationPolicy;
 import org.eclipse.persistence.internal.helper.DatabaseField;
 import org.eclipse.persistence.internal.identitymaps.CacheId;
 import org.eclipse.persistence.internal.security.PrivilegedAccessHelper;
@@ -38,6 +39,7 @@
 import org.eclipse.persistence.queries.UpdateObjectQuery;
 
 import java.io.Serializable;
+import java.util.ArrayList;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -462,7 +464,10 @@ public Object createPrimaryKeyInstance(Object object, AbstractSession session) {
             return  fieldValue;
         }
 
-        Object keyInstance = getPKClassInstance();
+        Class<?> pkClass = getPKClass();
+        boolean isRecord = pkClass != null && pkClass.isRecord();
+        Object keyInstance = isRecord ? null : getPKClassInstance();
+        List<Object> recordValues = isRecord ? new ArrayList<>(pkElementArray.length) : null;
         Set<ObjectReferenceMapping> usedObjectReferenceMappings = new HashSet<>();
         for (int index = 0; index < pkElementArray.length; index++) {
             Object keyObj = object;
@@ -492,11 +497,27 @@ public Object createPrimaryKeyInstance(Object object, AbstractSession session) {
                     fieldValue = mapping.getReferenceDescriptor().getCMPPolicy().createPrimaryKeyInstance(fieldValue, session);
                     usedObjectReferenceMappings.add((ObjectReferenceMapping)mapping);
                 }
-                accessor.setValue(nestedKeyInstance, fieldValue);
+                if (isRecord) {
+                    recordValues.add(fieldValue);
+                } else {
+                    accessor.setValue(nestedKeyInstance, fieldValue);
+                }
             }
         }
 
-        return keyInstance;
+        return isRecord ? createRecordInstance(pkClass, recordValues) : keyInstance;
+    }
+
+    /**
+     * Build a record primary key class instance from its component values using
+     * its canonical constructor. Records are immutable, so the default
+     * no-arg-constructor + field-reflection approach used for bean id classes
+     * cannot be applied.
+     */
+    private Object createRecordInstance(Class<?> recordClass, List<?> values) {
+        RecordInstantiationPolicy policy = new RecordInstantiationPolicy(recordClass);
+        policy.setValues(values);
+        return policy.buildNewInstance();
     }
 
     /**

jpa/eclipselink.jpa.test.jse/src/it/java/org/eclipse/persistence/jpa/test/record/TestRecordIdClass.java

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2024 Oracle and/or its affiliates. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0,
+ * or the Eclipse Distribution License v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ */
+
+package org.eclipse.persistence.jpa.test.record;
+
+import jakarta.persistence.EntityManager;
+import jakarta.persistence.EntityManagerFactory;
+
+import org.eclipse.persistence.jpa.test.framework.DDLGen;
+import org.eclipse.persistence.jpa.test.framework.Emf;
+import org.eclipse.persistence.jpa.test.framework.EmfRunner;
+import org.eclipse.persistence.jpa.test.record.model.RecordIdClass;
+import org.eclipse.persistence.jpa.test.record.model.RecordIdClassEntity;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+/**
+ * Tests for a {@code java.lang.Record} used as a JPA {@code @IdClass}.
+ */
+@RunWith(EmfRunner.class)
+public class TestRecordIdClass {
+
+    @Emf(createTables = DDLGen.DROP_CREATE, classes = { RecordIdClassEntity.class })
+    private EntityManagerFactory emf;
+
+    @Test
+    public void testPersistAndFind() {
+        EntityManager em = emf.createEntityManager();
+        try {
+            em.getTransaction().begin();
+            RecordIdClassEntity entity = new RecordIdClassEntity("code-1", "description-1");
+            em.persist(entity);
+            em.getTransaction().commit();
+            em.clear();
+
+            RecordIdClass idClass = new RecordIdClass(entity.getId(), entity.getCode());
+            RecordIdClassEntity found = em.find(RecordIdClassEntity.class, idClass);
+            assertNotNull("Entity should be found after persist", found);
+            assertEquals("description-1", found.getDescription());
+        } finally {
+            if (em.getTransaction().isActive()) {
+                em.getTransaction().rollback();
+            }
+            em.close();
+        }
+    }
+
+    @Test
+    public void testGetIdentifier() {
+        RecordIdClassEntity entity = new RecordIdClassEntity("code-1", "description-1");
+
+        Object identifier = emf.getPersistenceUnitUtil().getIdentifier(entity);
+
+        assertNotNull("Identifier should not be null", identifier);
+        assertTrue("Identifier should be a RecordIdClass", identifier instanceof RecordIdClass);
+        RecordIdClass idClass = (RecordIdClass) identifier;
+        assertEquals(entity.getId(), idClass.id());
+        assertEquals("code-1", idClass.code());
+    }
+}

jpa/eclipselink.jpa.test.jse/src/it/java/org/eclipse/persistence/jpa/test/record/model/RecordIdClass.java

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2024 Oracle and/or its affiliates. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0,
+ * or the Eclipse Distribution License v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ */
+
+package org.eclipse.persistence.jpa.test.record.model;
+
+import java.util.Objects;
+import java.util.UUID;
+
+/**
+ * A two-component record used as a JPA {@code @IdClass}.
+ */
+public record RecordIdClass(UUID id, String code) {
+
+    public RecordIdClass {
+        Objects.requireNonNull(id, "id must not be null");
+        Objects.requireNonNull(code, "code must not be null");
+    }
+
+    public RecordIdClass(String code) {
+        this(UUID.randomUUID(), code);
+    }
+}

jpa/eclipselink.jpa.test.jse/src/it/java/org/eclipse/persistence/jpa/test/record/model/RecordIdClassEntity.java

@@ -0,0 +1,53 @@
+/*
+ * Copyright (c) 2024 Oracle and/or its affiliates. All rights reserved.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License v. 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0,
+ * or the Eclipse Distribution License v. 1.0 which is available at
+ * http://www.eclipse.org/org/documents/edl-v10.php.
+ *
+ * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
+ */
+
+package org.eclipse.persistence.jpa.test.record.model;
+
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.IdClass;
+
+import java.util.UUID;
+
+@Entity
+@IdClass(RecordIdClass.class)
+public class RecordIdClassEntity {
+
+    @Id
+    private UUID id;
+
+    @Id
+    private String code;
+
+    private String description;
+
+    protected RecordIdClassEntity() {
+    }
+
+    public RecordIdClassEntity(String code, String description) {
+        this.id = UUID.randomUUID();
+        this.code = code;
+        this.description = description;
+    }
+
+    public UUID getId() {
+        return id;
+    }
+
+    public String getCode() {
+        return code;
+    }
+
+    public String getDescription() {
+        return description;
+    }
+}