Make Batch JPA auto-configuration back off without a DataSource

Fixes gh-17465

spring-boot-project/spring-boot-autoconfigure/src/main/java/org/springframework/boot/autoconfigure/batch/BatchConfigurerConfiguration.java

@@ -35,12 +35,12 @@ import org.springframework.transaction.PlatformTransactionManager;
  * @author Stephane Nicoll
  */
 @ConditionalOnClass(PlatformTransactionManager.class)
+@ConditionalOnBean(DataSource.class)
 @ConditionalOnMissingBean(BatchConfigurer.class)
 @Configuration
 class BatchConfigurerConfiguration {
 
 	@Configuration
-	@ConditionalOnBean(DataSource.class)
 	@ConditionalOnMissingBean(name = "entityManagerFactory")
 	static class JdbcBatchConfiguration {
 

spring-boot-project/spring-boot-autoconfigure/src/test/java/org/springframework/boot/autoconfigure/batch/BatchAutoConfigurationTests.java

@@ -61,6 +61,7 @@ import org.springframework.transaction.PlatformTransactionManager;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
+import static org.mockito.Mockito.mock;
 
 /**
  * Tests for {@link BatchAutoConfiguration}.
@@ -94,6 +95,12 @@ public class BatchAutoConfigurationTests {
 				.run((context) -> assertThat(context).doesNotHaveBean(BatchConfigurer.class));
 	}
 
+	@Test
+	public void whenThereIsAnEntityManagerFactoryButNoDataSourceAutoConfigurationBacksOff() {
+		this.contextRunner.withUserConfiguration(TestConfiguration.class, EntityManagerFactoryConfiguration.class)
+				.run((context) -> assertThat(context).doesNotHaveBean(BatchConfigurer.class));
+	}
+
 	@Test
 	public void testCustomConfigurationWithNoDatabase() {
 		this.contextRunner.withUserConfiguration(TestCustomConfiguration.class).run((context) -> {
@@ -250,6 +257,16 @@ public class BatchAutoConfigurationTests {
 
 	}
 
+	@Configuration
+	static class EntityManagerFactoryConfiguration {
+
+		@Bean
+		EntityManagerFactory entityManagerFactory() {
+			return mock(EntityManagerFactory.class);
+		}
+
+	}
+
 	@EnableBatchProcessing
 	@TestAutoConfigurationPackage(City.class)
 	protected static class TestCustomConfiguration implements BatchConfigurer {