Merge branch '6.0.x'

spring-orm/src/main/java/org/springframework/orm/jpa/vendor/EclipseLinkJpaDialect.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2018 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,6 +21,7 @@ import java.sql.SQLException;
 
 import jakarta.persistence.EntityManager;
 import jakarta.persistence.PersistenceException;
+import org.eclipse.persistence.sessions.DatabaseLogin;
 import org.eclipse.persistence.sessions.UnitOfWork;
 
 import org.springframework.jdbc.datasource.ConnectionHandle;
@@ -31,8 +32,7 @@ import org.springframework.transaction.TransactionException;
 
 /**
  * {@link org.springframework.orm.jpa.JpaDialect} implementation for Eclipse
- * Persistence Services (EclipseLink). Developed and tested against EclipseLink 2.7;
- * backwards-compatible with EclipseLink 2.5 and 2.6 at runtime.
+ * Persistence Services (EclipseLink). Compatible with EclipseLink 3.0/4.0.
  *
  * <p>By default, this class acquires an early EclipseLink transaction with an early
  * JDBC Connection for non-read-only transactions. This allows for mixing JDBC and
@@ -77,22 +77,40 @@ public class EclipseLinkJpaDialect extends DefaultJpaDialect {
 	public Object beginTransaction(EntityManager entityManager, TransactionDefinition definition)
 			throws PersistenceException, SQLException, TransactionException {
 
-		if (definition.getIsolationLevel() != TransactionDefinition.ISOLATION_DEFAULT) {
+		int currentIsolationLevel = definition.getIsolationLevel();
+		if (currentIsolationLevel != TransactionDefinition.ISOLATION_DEFAULT) {
 			// Pass custom isolation level on to EclipseLink's DatabaseLogin configuration
-			// (since Spring 4.1.2)
+			// (since Spring 4.1.2 / revised in 5.3.28)
 			UnitOfWork uow = entityManager.unwrap(UnitOfWork.class);
-			uow.getLogin().setTransactionIsolation(definition.getIsolationLevel());
+			DatabaseLogin databaseLogin = uow.getLogin();
+			// Synchronize on shared DatabaseLogin instance (-> concurrent transactions)
+			synchronized (databaseLogin) {
+				int originalIsolationLevel = databaseLogin.getTransactionIsolation();
+				// Apply current isolation level value, if necessary.
+				if (currentIsolationLevel != originalIsolationLevel) {
+					databaseLogin.setTransactionIsolation(currentIsolationLevel);
+				}
+				// Transaction begin including enforced JDBC Connection access
+				// (picking up current isolation level from DatabaseLogin)
+				entityManager.getTransaction().begin();
+				uow.beginEarlyTransaction();
+				entityManager.unwrap(Connection.class);
+				// Restore original isolation level value, if necessary.
+				if (currentIsolationLevel != originalIsolationLevel) {
+					databaseLogin.setTransactionIsolation(originalIsolationLevel);
+				}
+			}
 		}
-
-		entityManager.getTransaction().begin();
-
-		if (!definition.isReadOnly() && !this.lazyDatabaseTransaction) {
-			// Begin an early transaction to force EclipseLink to get a JDBC Connection
-			// so that Spring can manage transactions with JDBC as well as EclipseLink.
-			entityManager.unwrap(UnitOfWork.class).beginEarlyTransaction();
+		else {
+			entityManager.getTransaction().begin();
+			if (!definition.isReadOnly() && !this.lazyDatabaseTransaction) {
+				// Begin an early transaction to force EclipseLink to get a JDBC Connection
+				// so that Spring can manage transactions with JDBC as well as EclipseLink.
+				entityManager.unwrap(UnitOfWork.class).beginEarlyTransaction();
+			}
 		}
 
-		return null;
+		return entityManager;
 	}
 
 	@Override

spring-orm/src/main/java/org/springframework/orm/jpa/vendor/EclipseLinkJpaVendorAdapter.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2022 the original author or authors.
+ * Copyright 2002-2023 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -30,8 +30,7 @@ import org.springframework.lang.Nullable;
 
 /**
  * {@link org.springframework.orm.jpa.JpaVendorAdapter} implementation for Eclipse
- * Persistence Services (EclipseLink). Developed and tested against EclipseLink 2.7;
- * backwards-compatible with EclipseLink 2.5 and 2.6 at runtime.
+ * Persistence Services (EclipseLink). Compatible with EclipseLink 3.0/4.0.
  *
  * <p>Exposes EclipseLink's persistence provider and EntityManager extension interface,
  * and adapts {@link AbstractJpaVendorAdapter}'s common configuration settings.