Let Hibernate configure the transaction manager on WebSphere

Closes gh-8926

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaConfiguration.java

@@ -16,6 +16,7 @@
 
 package org.springframework.boot.autoconfigure.orm.jpa;
 
+import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.LinkedHashMap;
@@ -75,14 +76,6 @@ class HibernateJpaConfiguration extends JpaBaseConfiguration {
 			"org.hibernate.engine.transaction.jta.platform.internal.NoJtaPlatform",
 			"org.hibernate.service.jta.platform.internal.NoJtaPlatform" };
 
-	/**
-	 * {@code WebSphereExtendedJtaPlatform} implementations for various Hibernate
-	 * versions.
-	 */
-	private static final String[] WEBSPHERE_JTA_PLATFORM_CLASSES = {
-			"org.hibernate.engine.transaction.jta.platform.internal.WebSphereExtendedJtaPlatform",
-			"org.hibernate.service.jta.platform.internal.WebSphereExtendedJtaPlatform" };
-
 	private final HibernateProperties hibernateProperties;
 
 	private final HibernateDefaultDdlAutoProvider defaultDdlAutoProvider;
@@ -157,20 +150,15 @@ class HibernateJpaConfiguration extends JpaBaseConfiguration {
 	private void configureJtaPlatform(Map<String, Object> vendorProperties)
 			throws LinkageError {
 		JtaTransactionManager jtaTransactionManager = getJtaTransactionManager();
-		if (jtaTransactionManager != null) {
-			if (runningOnWebSphere()) {
-				// We can never use SpringJtaPlatform on WebSphere as
-				// WebSphereUowTransactionManager has a null TransactionManager
-				// which will cause Hibernate to NPE
-				configureWebSphereTransactionPlatform(vendorProperties);
-			}
-			else {
-				configureSpringJtaPlatform(vendorProperties, jtaTransactionManager);
-			}
-		}
-		else {
+		// Make sure Hibernate doesn't attempt to auto-detect a JTA platform
+		if (jtaTransactionManager == null) {
 			vendorProperties.put(JTA_PLATFORM, getNoJtaPlatformManager());
 		}
+		// As of Hibernate 5.2, Hibernate can fully integrate with the WebSphere
+		// transaction manager on its own.
+		else if (!runningOnWebSphere()) {
+			configureSpringJtaPlatform(vendorProperties, jtaTransactionManager);
+		}
 	}
 
 	private void configureProviderDisablesAutocommit(
@@ -193,15 +181,6 @@ class HibernateJpaConfiguration extends JpaBaseConfiguration {
 				getClass().getClassLoader());
 	}
 
-	private void configureWebSphereTransactionPlatform(
-			Map<String, Object> vendorProperties) {
-		vendorProperties.put(JTA_PLATFORM, getWebSphereJtaPlatformManager());
-	}
-
-	private Object getWebSphereJtaPlatformManager() {
-		return getJtaPlatformManager(WEBSPHERE_JTA_PLATFORM_CLASSES);
-	}
-
 	private void configureSpringJtaPlatform(Map<String, Object> vendorProperties,
 			JtaTransactionManager jtaTransactionManager) {
 		try {
@@ -233,11 +212,7 @@ class HibernateJpaConfiguration extends JpaBaseConfiguration {
 	}
 
 	private Object getNoJtaPlatformManager() {
-		return getJtaPlatformManager(NO_JTA_PLATFORM_CLASSES);
-	}
-
-	private Object getJtaPlatformManager(String[] candidates) {
-		for (String candidate : candidates) {
+		for (String candidate : NO_JTA_PLATFORM_CLASSES) {
 			try {
 				return Class.forName(candidate).newInstance();
 			}
@@ -245,7 +220,8 @@ class HibernateJpaConfiguration extends JpaBaseConfiguration {
 				// Continue searching
 			}
 		}
-		throw new IllegalStateException("Could not configure JTA platform");
+		throw new IllegalStateException("No available JtaPlatform candidates amongst"
+				+ Arrays.toString(NO_JTA_PLATFORM_CLASSES));
 	}
 
 	private static class NamingStrategiesHibernatePropertiesCustomizer

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/orm/jpa/HibernateJpaAutoConfigurationTests.java

@@ -35,7 +35,9 @@ import javax.transaction.UserTransaction;
 import com.zaxxer.hikari.HikariDataSource;
 import org.hibernate.boot.model.naming.ImplicitNamingStrategy;
 import org.hibernate.boot.model.naming.PhysicalNamingStrategy;
+import org.hibernate.engine.transaction.jta.platform.internal.NoJtaPlatform;
 import org.hibernate.engine.transaction.jta.platform.spi.JtaPlatform;
+import org.hibernate.internal.SessionFactoryImpl;
 import org.junit.Test;
 
 import org.springframework.beans.factory.BeanCreationException;
@@ -52,6 +54,8 @@ import org.springframework.boot.autoconfigure.transaction.jta.JtaAutoConfigurati
 import org.springframework.boot.orm.jpa.hibernate.SpringImplicitNamingStrategy;
 import org.springframework.boot.orm.jpa.hibernate.SpringJtaPlatform;
 import org.springframework.boot.orm.jpa.hibernate.SpringPhysicalNamingStrategy;
+import org.springframework.boot.test.context.assertj.AssertableApplicationContext;
+import org.springframework.boot.test.context.runner.ContextConsumer;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.orm.jpa.JpaTransactionManager;
@@ -148,13 +152,7 @@ public class HibernateJpaAutoConfigurationTests
 	public void jtaDefaultPlatform() {
 		contextRunner()
 				.withConfiguration(AutoConfigurations.of(JtaAutoConfiguration.class))
-				.run((context) -> {
-					Map<String, Object> jpaPropertyMap = context
-							.getBean(LocalContainerEntityManagerFactoryBean.class)
-							.getJpaPropertyMap();
-					assertThat(jpaPropertyMap.get("hibernate.transaction.jta.platform"))
-							.isInstanceOf(SpringJtaPlatform.class);
-				});
+				.run(assertJtaPlatform(SpringJtaPlatform.class));
 	}
 
 	@Test
@@ -164,14 +162,23 @@ public class HibernateJpaAutoConfigurationTests
 						"spring.jpa.properties.hibernate.transaction.jta.platform:"
 								+ TestJtaPlatform.class.getName())
 				.withConfiguration(AutoConfigurations.of(JtaAutoConfiguration.class))
-				.run((context) -> {
-					Map<String, Object> jpaPropertyMap = context
-							.getBean(LocalContainerEntityManagerFactoryBean.class)
-							.getJpaPropertyMap();
-					assertThat((String) jpaPropertyMap
-							.get("hibernate.transaction.jta.platform"))
-									.isEqualTo(TestJtaPlatform.class.getName());
-				});
+				.run(assertJtaPlatform(TestJtaPlatform.class));
+	}
+
+	@Test
+	public void jtaNotUsedByTheApplication() {
+		contextRunner().run(assertJtaPlatform(NoJtaPlatform.class));
+	}
+
+	private ContextConsumer<AssertableApplicationContext> assertJtaPlatform(
+			Class<? extends JtaPlatform> expectedType) {
+		return (context) -> {
+			SessionFactoryImpl sessionFactory = context
+					.getBean(LocalContainerEntityManagerFactoryBean.class)
+					.getNativeEntityManagerFactory().unwrap(SessionFactoryImpl.class);
+			assertThat(sessionFactory.getServiceRegistry().getService(JtaPlatform.class))
+					.isInstanceOf(expectedType);
+		};
 	}
 
 	@Test