Cleanup code

spring-data-jpa/src/main/java/org/springframework/data/jpa/mapping/JpaPersistentEntityImpl.java

@@ -59,6 +59,8 @@ public JpaPersistentEntityImpl(TypeInformation<T> information, ProxyIdAccessor p
 		super(information, null);
 
 		Assert.notNull(proxyIdAccessor, "ProxyIdAccessor must not be null");
+		Assert.notNull(metamodel, "JpaMetamodel must not be null");
+
 		this.proxyIdAccessor = proxyIdAccessor;
 		this.metamodel = metamodel;
 	}

spring-data-jpa/src/main/java/org/springframework/data/jpa/provider/JpaClassUtils.java

@@ -47,7 +47,7 @@ private JpaClassUtils() {}
 	 */
 	public static boolean isEntityManagerOfType(EntityManager em, String type) {
 
-		EntityManager entityManagerToUse = em.getDelegate()instanceof EntityManager delegate //
+		EntityManager entityManagerToUse = em.getDelegate() instanceof EntityManager delegate //
 				? delegate //
 				: em;
 

spring-data-jpa/src/main/java/org/springframework/data/jpa/provider/PersistenceProvider.java

@@ -198,7 +198,7 @@ public String getCommentHintKey() {
 
 	private static final Collection<PersistenceProvider> ALL = List.of(HIBERNATE, ECLIPSELINK, GENERIC_JPA);
 
-	static ConcurrentReferenceHashMap<Class<?>, PersistenceProvider> CACHE = new ConcurrentReferenceHashMap<>();
+	final static ConcurrentReferenceHashMap<Class<?>, PersistenceProvider> CACHE = new ConcurrentReferenceHashMap<>();
 	private final Iterable<String> entityManagerClassNames;
 	private final Iterable<String> metamodelClassNames;
 

spring-data-jpa/src/main/java/org/springframework/data/jpa/util/BeanDefinitionUtils.java

@@ -35,6 +35,7 @@
 import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
 import org.springframework.jndi.JndiObjectFactoryBean;
 import org.springframework.orm.jpa.AbstractEntityManagerFactoryBean;
+import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
 import org.springframework.util.ObjectUtils;
 
@@ -97,6 +98,8 @@ public static Iterable<String> getEntityManagerFactoryBeanNames(ListableBeanFact
 	public static Collection<EntityManagerFactoryBeanDefinition> getEntityManagerFactoryBeanDefinitions(
 			ConfigurableListableBeanFactory beanFactory) {
 
+		Assert.notNull(beanFactory, "ConfigurableListableBeanFactory must not be null!");
+
 		Set<EntityManagerFactoryBeanDefinition> definitions = new HashSet<>();
 
 		for (Class<?> type : EMF_TYPES) {

spring-data-jpa/src/main/java/org/springframework/data/jpa/util/JpaMetamodelCacheCleanup.java

@@ -30,7 +30,7 @@
 class JpaMetamodelCacheCleanup implements DisposableBean {
 
 	@Override
-	public void destroy() throws Exception {
+	public void destroy() {
 		JpaMetamodel.clear();
 	}
 }