Polishing.

Formatting.
Fix warnings.

See #2414
Original pull request #2419

Author: schauder

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

@@ -34,7 +34,6 @@
 import jakarta.persistence.TypedQuery;
 import jakarta.persistence.criteria.CriteriaBuilder;
 import jakarta.persistence.criteria.CriteriaQuery;
-import jakarta.persistence.criteria.Order;
 import jakarta.persistence.criteria.ParameterExpression;
 import jakarta.persistence.criteria.Path;
 import jakarta.persistence.criteria.Predicate;
@@ -212,13 +211,13 @@ public void deleteAllByIdInBatch(Iterable<ID> ids) {
 		}
 
 		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)));
+			// generate entity (proxies) without accessing the database.
+			ids.forEach(id -> entities.add(getReferenceById(id)));
 			deleteAllInBatch(entities);
 		} else {
+
 			String queryString = String.format(DELETE_ALL_QUERY_BY_ID_STRING, entityInformation.getEntityName(),
 					entityInformation.getIdAttribute().getName());
 
@@ -292,7 +291,6 @@ public Optional<T> findById(ID id) {
 	 * Returns {@link QueryHints} with the query hints based on the current {@link CrudMethodMetadata} and potential
 	 * {@link EntityGraph} information.
 	 *
-	 * @return
 	 */
 	protected QueryHints getQueryHints() {
 		return metadata == null ? NoHints.INSTANCE : DefaultQueryHints.of(entityInformation, metadata);
@@ -377,7 +375,7 @@ public List<T> findAllById(Iterable<ID> ids) {
 
 		if (entityInformation.hasCompositeId()) {
 
-			List<T> results = new ArrayList<T>();
+			List<T> results = new ArrayList<>();
 
 			for (ID id : ids) {
 				findById(id).ifPresent(results::add);
@@ -388,7 +386,7 @@ public List<T> findAllById(Iterable<ID> ids) {
 
 		Collection<ID> idCollection = Streamable.of(ids).toList();
 
-		ByIdsSpecification<T> specification = new ByIdsSpecification<T>(entityInformation);
+		ByIdsSpecification<T> specification = new ByIdsSpecification<>(entityInformation);
 		TypedQuery<T> query = getQuery(specification, Sort.unsorted());
 
 		return query.setParameter(specification.parameter, idCollection).getResultList();
@@ -403,7 +401,7 @@ public List<T> findAll(Sort sort) {
 	public Page<T> findAll(Pageable pageable) {
 
 		if (isUnpaged(pageable)) {
-			return new PageImpl<T>(findAll());
+			return new PageImpl<>(findAll());
 		}
 
 		return findAll((Specification<T>) null, pageable);
@@ -428,7 +426,7 @@ public List<T> findAll(@Nullable Specification<T> spec) {
 	public Page<T> findAll(@Nullable Specification<T> spec, Pageable pageable) {
 
 		TypedQuery<T> query = getQuery(spec, pageable);
-		return isUnpaged(pageable) ? new PageImpl<T>(query.getResultList())
+		return isUnpaged(pageable) ? new PageImpl<>(query.getResultList())
 				: readPage(query, getDomainClass(), pageable, spec);
 	}
 
@@ -442,7 +440,7 @@ public <S extends T> Optional<S> findOne(Example<S> example) {
 
 		try {
 			return Optional
-					.of(getQuery(new ExampleSpecification<S>(example, escapeCharacter), example.getProbeType(), Sort.unsorted())
+					.of(getQuery(new ExampleSpecification<>(example, escapeCharacter), example.getProbeType(), Sort.unsorted())
 							.getSingleResult());
 		} catch (NoResultException e) {
 			return Optional.empty();
@@ -452,7 +450,7 @@ public <S extends T> Optional<S> findOne(Example<S> example) {
 	@Override
 	public <S extends T> long count(Example<S> example) {
 		return executeCountQuery(
-				getCountQuery(new ExampleSpecification<S>(example, escapeCharacter), example.getProbeType()));
+				getCountQuery(new ExampleSpecification<>(example, escapeCharacter), example.getProbeType()));
 	}
 
 	@Override
@@ -468,13 +466,13 @@ public <S extends T> boolean exists(Example<S> example) {
 
 	@Override
 	public <S extends T> List<S> findAll(Example<S> example) {
-		return getQuery(new ExampleSpecification<S>(example, escapeCharacter), example.getProbeType(), Sort.unsorted())
+		return getQuery(new ExampleSpecification<>(example, escapeCharacter), example.getProbeType(), Sort.unsorted())
 				.getResultList();
 	}
 
 	@Override
 	public <S extends T> List<S> findAll(Example<S> example, Sort sort) {
-		return getQuery(new ExampleSpecification<S>(example, escapeCharacter), example.getProbeType(), sort)
+		return getQuery(new ExampleSpecification<>(example, escapeCharacter), example.getProbeType(), sort)
 				.getResultList();
 	}
 
@@ -548,7 +546,7 @@ public <S extends T> List<S> saveAll(Iterable<S> entities) {
 
 		Assert.notNull(entities, "Entities must not be null!");
 
-		List<S> result = new ArrayList<S>();
+		List<S> result = new ArrayList<>();
 
 		for (S entity : entities) {
 			result.add(save(entity));
@@ -580,7 +578,6 @@ public void flush() {
 	 * @param query must not be {@literal null}.
 	 * @param spec can be {@literal null}.
 	 * @param pageable must not be {@literal null}.
-	 * @return
 	 * @deprecated use {@link #readPage(TypedQuery, Class, Pageable, Specification)} instead
 	 */
 	@Deprecated
@@ -596,7 +593,6 @@ protected Page<T> readPage(TypedQuery<T> query, Pageable pageable, @Nullable Spe
 	 * @param domainClass must not be {@literal null}.
 	 * @param spec can be {@literal null}.
 	 * @param pageable can be {@literal null}.
-	 * @return
 	 */
 	protected <S extends T> Page<S> readPage(TypedQuery<S> query, final Class<S> domainClass, Pageable pageable,
 			@Nullable Specification<S> spec) {
@@ -615,7 +611,6 @@ protected <S extends T> Page<S> readPage(TypedQuery<S> query, final Class<S> dom
 	 *
 	 * @param spec can be {@literal null}.
 	 * @param pageable must not be {@literal null}.
-	 * @return
 	 */
 	protected TypedQuery<T> getQuery(@Nullable Specification<T> spec, Pageable pageable) {
 
@@ -629,7 +624,6 @@ protected TypedQuery<T> getQuery(@Nullable Specification<T> spec, Pageable pagea
 	 * @param spec can be {@literal null}.
 	 * @param domainClass must not be {@literal null}.
 	 * @param pageable must not be {@literal null}.
-	 * @return
 	 */
 	protected <S extends T> TypedQuery<S> getQuery(@Nullable Specification<S> spec, Class<S> domainClass,
 			Pageable pageable) {
@@ -643,7 +637,6 @@ protected <S extends T> TypedQuery<S> getQuery(@Nullable Specification<S> spec,
 	 *
 	 * @param spec can be {@literal null}.
 	 * @param sort must not be {@literal null}.
-	 * @return
 	 */
 	protected TypedQuery<T> getQuery(@Nullable Specification<T> spec, Sort sort) {
 		return getQuery(spec, getDomainClass(), sort);
@@ -655,7 +648,6 @@ protected TypedQuery<T> getQuery(@Nullable Specification<T> spec, Sort sort) {
 	 * @param spec can be {@literal null}.
 	 * @param domainClass must not be {@literal null}.
 	 * @param sort must not be {@literal null}.
-	 * @return
 	 */
 	protected <S extends T> TypedQuery<S> getQuery(@Nullable Specification<S> spec, Class<S> domainClass, Sort sort) {
 
@@ -676,7 +668,6 @@ protected <S extends T> TypedQuery<S> getQuery(@Nullable Specification<S> spec,
 	 * Creates a new count query for the given {@link Specification}.
 	 *
 	 * @param spec can be {@literal null}.
-	 * @return
 	 * @deprecated override {@link #getCountQuery(Specification, Class)} instead
 	 */
 	@Deprecated
@@ -689,7 +680,6 @@ protected TypedQuery<Long> getCountQuery(@Nullable Specification<T> spec) {
 	 *
 	 * @param spec can be {@literal null}.
 	 * @param domainClass must not be {@literal null}.
-	 * @return
 	 */
 	protected <S extends T> TypedQuery<Long> getCountQuery(@Nullable Specification<S> spec, Class<S> domainClass) {
 
@@ -705,7 +695,7 @@ protected <S extends T> TypedQuery<Long> getCountQuery(@Nullable Specification<S
 		}
 
 		// Remove all Orders the Specifications might have applied
-		query.orderBy(Collections.<Order> emptyList());
+		query.orderBy(Collections.emptyList());
 
 		return em.createQuery(query);
 	}
@@ -716,7 +706,6 @@ protected <S extends T> TypedQuery<Long> getCountQuery(@Nullable Specification<S
 	 * @param spec can be {@literal null}.
 	 * @param domainClass must not be {@literal null}.
 	 * @param query must not be {@literal null}.
-	 * @return
 	 */
 	private <S, U extends T> Root<U> applySpecificationToCriteria(@Nullable Specification<U> spec, Class<U> domainClass,
 			CriteriaQuery<S> query) {
@@ -762,7 +751,6 @@ private void applyQueryHints(Query query) {
 	 * Executes a count query and transparently sums up all values returned.
 	 *
 	 * @param query must not be {@literal null}.
-	 * @return
 	 */
 	private static long executeCountQuery(TypedQuery<Long> query) {
 
@@ -830,8 +818,8 @@ private static class ExampleSpecification<T> implements Specification<T> {
 		/**
 		 * Creates new {@link ExampleSpecification}.
 		 *
-		 * @param example
-		 * @param escapeCharacter
+		 * @param example the example to base the specification of. Must not be {@literal null}.
+		 * @param escapeCharacter the escape character to use for like expressions. Must not be {@literal null}.
 		 */
 		ExampleSpecification(Example<T> example, EscapeCharacter escapeCharacter) {
 

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

@@ -18,6 +18,7 @@
 import static org.assertj.core.api.Assertions.*;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 import jakarta.persistence.EntityManager;
@@ -113,15 +114,15 @@ void shouldSupportSavingEntitiesWithCompositeKeyClassesWithEmbeddedIdsAndDerived
 	}
 
 	@Test // DATAJPA-472, DATAJPA-912
-	void shouldSupportFindAllWithPageableAndEntityWithIdClass() throws Exception {
+	void shouldSupportFindAllWithPageableAndEntityWithIdClass() {
 
 		IdClassExampleDepartment dep = new IdClassExampleDepartment();
 		dep.setName("TestDepartment");
 		dep.setDepartmentId(-1);
 
 		IdClassExampleEmployee emp = new IdClassExampleEmployee();
 		emp.setDepartment(dep);
-		emp = employeeRepositoryWithIdClass.save(emp);
+		employeeRepositoryWithIdClass.save(emp);
 
 		Page<IdClassExampleEmployee> page = employeeRepositoryWithIdClass.findAll(PageRequest.of(0, 1));
 
@@ -130,7 +131,7 @@ void shouldSupportFindAllWithPageableAndEntityWithIdClass() throws Exception {
 	}
 
 	@Test // DATAJPA-2414
-	void shouldSupportDeleteAllByIdInBatchWithIdClass() throws Exception {
+	void shouldSupportDeleteAllByIdInBatchWithIdClass() {
 
 		IdClassExampleDepartment dep = new IdClassExampleDepartment();
 		dep.setName("TestDepartment");
@@ -143,7 +144,7 @@ void shouldSupportDeleteAllByIdInBatchWithIdClass() throws Exception {
 		IdClassExampleEmployeePK key = new IdClassExampleEmployeePK(emp.getEmpId(), dep.getDepartmentId());
 		assertThat(employeeRepositoryWithIdClass.findById(key)).isNotEmpty();
 
-		employeeRepositoryWithIdClass.deleteAllByIdInBatch(Arrays.asList(key));
+		employeeRepositoryWithIdClass.deleteAllByIdInBatch(Collections.singletonList(key));
 
 		em.flush();
 		em.clear();
@@ -170,7 +171,7 @@ void sortByEmbeddedPkFieldInCompositePkWithEmbeddedIdInQueryDsl() {
 		EmbeddedIdExampleEmployee emp2 = new EmbeddedIdExampleEmployee();
 		emp2.setEmployeePk(new EmbeddedIdExampleEmployeePK(2L, null));
 		emp2.setDepartment(dep1);
-		emp2 = employeeRepositoryWithEmbeddedId.save(emp2);
+		employeeRepositoryWithEmbeddedId.save(emp2);
 
 		EmbeddedIdExampleEmployee emp3 = new EmbeddedIdExampleEmployee();
 		emp3.setEmployeePk(new EmbeddedIdExampleEmployeePK(1L, null));
@@ -206,7 +207,7 @@ void sortByEmbeddedPkFieldInCompositePkWithIdClassInQueryDsl() {
 		IdClassExampleEmployee emp2 = new IdClassExampleEmployee();
 		emp2.setEmpId(2L);
 		emp2.setDepartment(dep1);
-		emp2 = employeeRepositoryWithIdClass.save(emp2);
+		employeeRepositoryWithIdClass.save(emp2);
 
 		IdClassExampleEmployee emp3 = new IdClassExampleEmployee();
 		emp3.setEmpId(1L);
@@ -276,7 +277,7 @@ void shouldAllowFindAllWithIdsForEntitiesWithCompoundIdClassKeys() {
 		IdClassExampleEmployee emp1 = new IdClassExampleEmployee();
 		emp1.setEmpId(3L);
 		emp1.setDepartment(dep2);
-		emp1 = employeeRepositoryWithIdClass.save(emp1);
+		employeeRepositoryWithIdClass.save(emp1);
 
 		IdClassExampleDepartment dep1 = new IdClassExampleDepartment();
 		dep1.setDepartmentId(1L);
@@ -285,7 +286,7 @@ void shouldAllowFindAllWithIdsForEntitiesWithCompoundIdClassKeys() {
 		IdClassExampleEmployee emp2 = new IdClassExampleEmployee();
 		emp2.setEmpId(2L);
 		emp2.setDepartment(dep1);
-		emp2 = employeeRepositoryWithIdClass.save(emp2);
+		employeeRepositoryWithIdClass.save(emp2);
 
 		IdClassExampleEmployeePK emp1PK = new IdClassExampleEmployeePK();
 		emp1PK.setDepartment(2L);