Support compound IdClass ID's when calling deleteAllByIdInBatch.

Convert ID's to entities and pass them to deleteAllInBatch.

Closes #2414
Original pull request #2419

Author: ejl888

src/main/java/org/springframework/data/jpa/repository/support/SimpleJpaRepository.java

@@ -81,6 +81,7 @@
  * @author Jesse Wouters
  * @author Greg Turnquist
  * @author Yanming Zhou
+ * @author Ernst-Jan van der Laan
  */
 @Repository
 @Transactional(readOnly = true)
@@ -226,13 +227,22 @@ public void deleteAllByIdInBatch(Iterable<ID> ids) {
 			return;
 		}
 
-		String queryString = String.format(DELETE_ALL_QUERY_BY_ID_STRING, entityInformation.getEntityName(),
-				entityInformation.getIdAttribute().getName());
+		if (entityInformation.hasCompositeId()) {
+			// XXX Hibernate just creates an empty Entity when doing the getById.
+			// Others might do a select right away causing a big performance penalty.
+			// See JavaDoc for getById.
+			List<T> entities = new ArrayList<>();
+			ids.forEach(id -> entities.add(getById(id)));
+			deleteAllInBatch(entities);
+		} else {
+			String queryString = String.format(DELETE_ALL_QUERY_BY_ID_STRING, entityInformation.getEntityName(),
+					entityInformation.getIdAttribute().getName());
 
-		Query query = em.createQuery(queryString);
-		query.setParameter("ids", ids);
+			Query query = em.createQuery(queryString);
+			query.setParameter("ids", ids);
 
-		query.executeUpdate();
+			query.executeUpdate();
+		}
 	}
 
 	/*

src/test/java/org/springframework/data/jpa/repository/RepositoryWithCompositeKeyTests.java

@@ -20,9 +20,10 @@
 import java.util.Arrays;
 import java.util.List;
 
+import javax.persistence.EntityManager;
+
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.extension.ExtendWith;
-
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.data.domain.Page;
 import org.springframework.data.domain.PageRequest;
@@ -47,6 +48,7 @@
  * @author Thomas Darimont
  * @author Mark Paluch
  * @author Jens Schauder
+ * @author Ernst-Jan van der Laan
  */
 @ExtendWith(SpringExtension.class)
 @ContextConfiguration(classes = SampleConfig.class)
@@ -55,6 +57,7 @@ public class RepositoryWithCompositeKeyTests {
 
 	@Autowired EmployeeRepositoryWithIdClass employeeRepositoryWithIdClass;
 	@Autowired EmployeeRepositoryWithEmbeddedId employeeRepositoryWithEmbeddedId;
+	@Autowired EntityManager em;
 
 	/**
 	 * @see <a href="download.oracle.com/otn-pub/jcp/persistence-2_1-fr-eval-spec/JavaPersistence.pdf">Final JPA 2.0
@@ -126,6 +129,28 @@ void shouldSupportFindAllWithPageableAndEntityWithIdClass() throws Exception {
 		assertThat(page.getTotalElements()).isEqualTo(1L);
 	}
 
+	@Test // DATAJPA-2414
+	void shouldSupportDeleteAllByIdInBatchWithIdClass() throws Exception {
+
+		IdClassExampleDepartment dep = new IdClassExampleDepartment();
+		dep.setName("TestDepartment");
+		dep.setDepartmentId(-1);
+
+		IdClassExampleEmployee emp = new IdClassExampleEmployee();
+		emp.setDepartment(dep);
+		emp = employeeRepositoryWithIdClass.save(emp);
+
+		IdClassExampleEmployeePK key = new IdClassExampleEmployeePK(emp.getEmpId(), dep.getDepartmentId());
+		assertThat(employeeRepositoryWithIdClass.findById(key)).isNotEmpty();
+
+		employeeRepositoryWithIdClass.deleteAllByIdInBatch(Arrays.asList(key));
+
+		em.flush();
+		em.clear();
+
+		assertThat(employeeRepositoryWithIdClass.findById(key)).isEmpty();
+	}
+
 	@Test // DATAJPA-497
 	void sortByEmbeddedPkFieldInCompositePkWithEmbeddedIdInQueryDsl() {