HibernateJpaVendorAdapter sets connection release mode ON_CLOSE in non-PersistenceUnitInfo bootstrap scenario

Issue: SPR-16162

Author: jhoeller

spring-orm/src/main/java/org/springframework/orm/jpa/JpaVendorAdapter.java

@@ -63,6 +63,12 @@ default String getPersistenceProviderRootPackage() {
 	 * non-unit-dependent properties. Effectively, this PersistenceUnitInfo-based
 	 * variant only needs to be implemented if there is an actual need to react
 	 * to unit-specific characteristics such as the transaction type.
+	 * <p><b>NOTE:</b> This variant will only be invoked in case of Java EE style
+	 * container bootstrapping where a {@link PersistenceUnitInfo} is present
+	 * (i.e. {@link LocalContainerEntityManagerFactoryBean}. In case of simple
+	 * Java SE style bootstrapping via {@link javax.persistence.Persistence}
+	 * (i.e. {@link LocalEntityManagerFactoryBean}), the parameter-less
+	 * {@link #getJpaPropertyMap()} variant will be called directly.
 	 * @param pui the PersistenceUnitInfo for the current persistence unit
 	 * @return a Map of JPA properties, as accepted by the standard JPA bootstrap
 	 * facilities, or an empty Map if there are no properties to expose

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

@@ -115,32 +115,16 @@ public String getPersistenceProviderRootPackage() {
 
 	@Override
 	public Map<String, Object> getJpaPropertyMap(PersistenceUnitInfo pui) {
-		Map<String, Object> jpaProperties = getJpaPropertyMap();
-
-		if (this.jpaDialect.prepareConnection && pui.getTransactionType() != PersistenceUnitTransactionType.JTA) {
-			// Hibernate 5.1/5.2: manually enforce connection release mode ON_CLOSE (the former default)
-			try {
-				// Try Hibernate 5.2
-				AvailableSettings.class.getField("CONNECTION_HANDLING");
-				jpaProperties.put("hibernate.connection.handling_mode", "DELAYED_ACQUISITION_AND_HOLD");
-			}
-			catch (NoSuchFieldException ex) {
-				// Try Hibernate 5.1
-				try {
-					AvailableSettings.class.getField("ACQUIRE_CONNECTIONS");
-					jpaProperties.put("hibernate.connection.release_mode", "ON_CLOSE");
-				}
-				catch (NoSuchFieldException ex2) {
-					// on Hibernate 5.0.x or lower - no need to change the default there
-				}
-			}
-		}
-
-		return jpaProperties;
+		return buildJpaPropertyMap(this.jpaDialect.prepareConnection &&
+				pui.getTransactionType() != PersistenceUnitTransactionType.JTA);
 	}
 
 	@Override
 	public Map<String, Object> getJpaPropertyMap() {
+		return buildJpaPropertyMap(this.jpaDialect.prepareConnection);
+	}
+
+	private Map<String, Object> buildJpaPropertyMap(boolean connectionReleaseOnClose) {
 		Map<String, Object> jpaProperties = new HashMap<>();
 
 		if (getDatabasePlatform() != null) {
@@ -160,6 +144,25 @@ public Map<String, Object> getJpaPropertyMap() {
 			jpaProperties.put(AvailableSettings.SHOW_SQL, "true");
 		}
 
+		if (connectionReleaseOnClose) {
+			// Hibernate 5.1/5.2: manually enforce connection release mode ON_CLOSE (the former default)
+			try {
+				// Try Hibernate 5.2
+				AvailableSettings.class.getField("CONNECTION_HANDLING");
+				jpaProperties.put("hibernate.connection.handling_mode", "DELAYED_ACQUISITION_AND_HOLD");
+			}
+			catch (NoSuchFieldException ex) {
+				// Try Hibernate 5.1
+				try {
+					AvailableSettings.class.getField("ACQUIRE_CONNECTIONS");
+					jpaProperties.put("hibernate.connection.release_mode", "ON_CLOSE");
+				}
+				catch (NoSuchFieldException ex2) {
+					// on Hibernate 5.0.x or lower - no need to change the default there
+				}
+			}
+		}
+
 		return jpaProperties;
 	}