#232 - Added example to show JPA stream executions are rejected without surrounding transaction.

jpa/java8/pom.xml

@@ -10,5 +10,9 @@
 
 	<artifactId>spring-data-jpa-java8</artifactId>
 	<name>Spring Data JPA - Java 8 specific features</name>
+	
+	<properties>
+		<spring-data-releasetrain.version>Ingalls-BUILD-SNAPSHOT</spring-data-releasetrain.version>
+	</properties>
 
 </project>

jpa/java8/src/test/java/example/springdata/jpa/java8/Java8IntegrationTests.java

@@ -30,6 +30,7 @@ import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.dao.InvalidDataAccessApiUsageException;
 import org.springframework.test.context.junit4.SpringRunner;
 import org.springframework.transaction.annotation.Propagation;
 import org.springframework.transaction.annotation.Transactional;
@@ -106,6 +107,16 @@ public class Java8IntegrationTests {
 		}
 	}
 
+	/**
+	 * Query methods using streaming need to be used inside a surrounding transaction to keep the connection open while
+	 * the stream is consumed. We simulate that not being the case by actively disabling the transaction here.
+	 */
+	@Test(expected = InvalidDataAccessApiUsageException.class)
+	@Transactional(propagation = Propagation.NOT_SUPPORTED)
+	public void rejectsStreamExecutionIfNoSurroundingTransactionActive() {
+		repository.findAllByLastnameIsNotNull();
+	}
+
 	/**
 	 * Here we demonstrate the usage of {@link CompletableFuture} as a result wrapper for asynchronous repository query
 	 * methods. Note, that we need to disable the surrounding transaction to be able to asynchronously read the written