Rename em as entityManager in SimpleJpaRepository.

See #3120

Author: jeomxon

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

@@ -94,7 +94,7 @@ public class SimpleJpaRepository<T, ID> implements JpaRepositoryImplementation<T
 	private static final String ID_MUST_NOT_BE_NULL = "The given id must not be null";
 
 	private final JpaEntityInformation<T, ?> entityInformation;
-	private final EntityManager em;
+	private final EntityManager entityManager;
 	private final PersistenceProvider provider;
 
 	private @Nullable CrudMethodMetadata metadata;
@@ -112,18 +112,18 @@ public SimpleJpaRepository(JpaEntityInformation<T, ?> entityInformation, EntityM
 		Assert.notNull(entityManager, "EntityManager must not be null");
 
 		this.entityInformation = entityInformation;
-		this.em = entityManager;
+		this.entityManager = entityManager;
 		this.provider = PersistenceProvider.fromEntityManager(entityManager);
 	}
 
 	/**
 	 * Creates a new {@link SimpleJpaRepository} to manage objects of the given domain type.
 	 *
 	 * @param domainClass must not be {@literal null}.
-	 * @param em must not be {@literal null}.
+	 * @param entityManager must not be {@literal null}.
 	 */
-	public SimpleJpaRepository(Class<T> domainClass, EntityManager em) {
-		this(JpaEntityInformationSupport.getEntityInformation(domainClass, em), em);
+	public SimpleJpaRepository(Class<T> domainClass, EntityManager entityManager) {
+		this(JpaEntityInformationSupport.getEntityInformation(domainClass, entityManager), entityManager);
 	}
 
 	/**
@@ -183,14 +183,14 @@ public void delete(T entity) {
 
 		Class<?> type = ProxyUtils.getUserClass(entity);
 
-		T existing = (T) em.find(type, entityInformation.getId(entity));
+		T existing = (T) entityManager.find(type, entityInformation.getId(entity));
 
 		// if the entity to be deleted doesn't exist, delete is a NOOP
 		if (existing == null) {
 			return;
 		}
 
-		em.remove(em.contains(entity) ? entity : em.merge(entity));
+		entityManager.remove(entityManager.contains(entity) ? entity : entityManager.merge(entity));
 	}
 
 	@Override
@@ -225,7 +225,7 @@ public void deleteAllByIdInBatch(Iterable<ID> ids) {
 			String queryString = String.format(DELETE_ALL_QUERY_BY_ID_STRING, entityInformation.getEntityName(),
 					entityInformation.getIdAttribute().getName());
 
-			Query query = em.createQuery(queryString);
+			Query query = entityManager.createQuery(queryString);
 
 			/*
 			 * Some JPA providers require {@code ids} to be a {@link Collection} so we must convert if it's not already.
@@ -266,7 +266,8 @@ public void deleteAllInBatch(Iterable<T> entities) {
 			return;
 		}
 
-		applyAndBind(getQueryString(DELETE_ALL_QUERY_STRING, entityInformation.getEntityName()), entities, em)
+		applyAndBind(getQueryString(DELETE_ALL_QUERY_STRING, entityInformation.getEntityName()), entities,
+				entityManager)
 				.executeUpdate();
 	}
 
@@ -283,7 +284,7 @@ public void deleteAll() {
 	@Transactional
 	public void deleteAllInBatch() {
 
-		Query query = em.createQuery(getDeleteAllQueryString());
+		Query query = entityManager.createQuery(getDeleteAllQueryString());
 
 		applyQueryHints(query);
 
@@ -298,13 +299,13 @@ public Optional<T> findById(ID id) {
 		Class<T> domainType = getDomainClass();
 
 		if (metadata == null) {
-			return Optional.ofNullable(em.find(domainType, id));
+			return Optional.ofNullable(entityManager.find(domainType, id));
 		}
 
 		LockModeType type = metadata.getLockModeType();
 		Map<String, Object> hints = getHints();
 
-		return Optional.ofNullable(type == null ? em.find(domainType, id, hints) : em.find(domainType, id, type, hints));
+		return Optional.ofNullable(type == null ? entityManager.find(domainType, id, hints) : entityManager.find(domainType, id, type, hints));
 	}
 
 	@Deprecated
@@ -327,7 +328,7 @@ public T getById(ID id) {
 	public T getReferenceById(ID id) {
 
 		Assert.notNull(id, ID_MUST_NOT_BE_NULL);
-		return em.getReference(getDomainClass(), id);
+		return entityManager.getReference(getDomainClass(), id);
 	}
 
 	@Override
@@ -344,7 +345,7 @@ public boolean existsById(ID id) {
 		Iterable<String> idAttributeNames = entityInformation.getIdAttributeNames();
 		String existsQuery = QueryUtils.getExistsQueryString(entityName, placeholder, idAttributeNames);
 
-		TypedQuery<Long> query = em.createQuery(existsQuery, Long.class);
+		TypedQuery<Long> query = entityManager.createQuery(existsQuery, Long.class);
 
 		applyQueryHints(query);
 
@@ -470,13 +471,13 @@ public <S extends T> long count(Example<S> example) {
 	public <S extends T> boolean exists(Example<S> example) {
 
 		Specification<S> spec = new ExampleSpecification<>(example, this.escapeCharacter);
-		CriteriaQuery<Integer> cq = this.em.getCriteriaBuilder() //
+		CriteriaQuery<Integer> cq = this.entityManager.getCriteriaBuilder() //
 				.createQuery(Integer.class) //
-				.select(this.em.getCriteriaBuilder().literal(1));
+				.select(this.entityManager.getCriteriaBuilder().literal(1));
 
 		applySpecificationToCriteria(spec, example.getProbeType(), cq);
 
-		TypedQuery<Integer> query = applyRepositoryMethodMetadata(this.em.createQuery(cq));
+		TypedQuery<Integer> query = applyRepositoryMethodMetadata(this.entityManager.createQuery(cq));
 		return query.setMaxResults(1).getResultList().size() == 1;
 	}
 
@@ -565,7 +566,7 @@ public <S extends T, R> R findBy(Specification<T> spec, Function<FetchableFluent
 	@Override
 	public long count() {
 
-		TypedQuery<Long> query = em.createQuery(getCountQueryString(), Long.class);
+		TypedQuery<Long> query = entityManager.createQuery(getCountQueryString(), Long.class);
 
 		applyQueryHintsForCount(query);
 
@@ -584,10 +585,10 @@ public <S extends T> S save(S entity) {
 		Assert.notNull(entity, "Entity must not be null");
 
 		if (entityInformation.isNew(entity)) {
-			em.persist(entity);
+			entityManager.persist(entity);
 			return entity;
 		} else {
-			return em.merge(entity);
+			return entityManager.merge(entity);
 		}
 	}
 
@@ -629,7 +630,7 @@ public <S extends T> List<S> saveAllAndFlush(Iterable<S> entities) {
 	@Transactional
 	@Override
 	public void flush() {
-		em.flush();
+		entityManager.flush();
 	}
 
 	/**
@@ -712,7 +713,7 @@ protected TypedQuery<T> getQuery(@Nullable Specification<T> spec, Sort sort) {
 	 */
 	protected <S extends T> TypedQuery<S> getQuery(@Nullable Specification<S> spec, Class<S> domainClass, Sort sort) {
 
-		CriteriaBuilder builder = em.getCriteriaBuilder();
+		CriteriaBuilder builder = entityManager.getCriteriaBuilder();
 		CriteriaQuery<S> query = builder.createQuery(domainClass);
 
 		Root<S> root = applySpecificationToCriteria(spec, domainClass, query);
@@ -722,7 +723,7 @@ protected <S extends T> TypedQuery<S> getQuery(@Nullable Specification<S> spec,
 			query.orderBy(toOrders(sort, root, builder));
 		}
 
-		return applyRepositoryMethodMetadata(em.createQuery(query));
+		return applyRepositoryMethodMetadata(entityManager.createQuery(query));
 	}
 
 	/**
@@ -744,7 +745,7 @@ protected TypedQuery<Long> getCountQuery(@Nullable Specification<T> spec) {
 	 */
 	protected <S extends T> TypedQuery<Long> getCountQuery(@Nullable Specification<S> spec, Class<S> domainClass) {
 
-		CriteriaBuilder builder = em.getCriteriaBuilder();
+		CriteriaBuilder builder = entityManager.getCriteriaBuilder();
 		CriteriaQuery<Long> query = builder.createQuery(Long.class);
 
 		Root<S> root = applySpecificationToCriteria(spec, domainClass, query);
@@ -758,7 +759,7 @@ protected <S extends T> TypedQuery<Long> getCountQuery(@Nullable Specification<S
 		// Remove all Orders the Specifications might have applied
 		query.orderBy(Collections.emptyList());
 
-		return applyRepositoryMethodMetadataForCount(em.createQuery(query));
+		return applyRepositoryMethodMetadataForCount(entityManager.createQuery(query));
 	}
 
 	/**
@@ -795,7 +796,7 @@ private <S, U extends T> Root<U> applySpecificationToCriteria(@Nullable Specific
 			return root;
 		}
 
-		CriteriaBuilder builder = em.getCriteriaBuilder();
+		CriteriaBuilder builder = entityManager.getCriteriaBuilder();
 		Predicate predicate = spec.toPredicate(root, query, builder);
 
 		if (predicate != null) {
@@ -825,7 +826,7 @@ private void applyQueryHints(Query query) {
 			return;
 		}
 
-		getQueryHints().withFetchGraphs(em).forEach(query::setHint);
+		getQueryHints().withFetchGraphs(entityManager).forEach(query::setHint);
 		applyComment(metadata, query::setHint);
 	}
 
@@ -854,7 +855,7 @@ private Map<String, Object> getHints() {
 
 		Map<String, Object> hints = new HashMap<>();
 
-		getQueryHints().withFetchGraphs(em).forEach(hints::put);
+		getQueryHints().withFetchGraphs(entityManager).forEach(hints::put);
 
 		if (metadata != null) {
 			applyComment(metadata, hints::put);