Prevent Hibernate basics types to be treated as DTO projection

fixes #3929

Signed-off-by: Johannes Edmeier <[email protected]>

Author: joshiste

spring-data-jpa/src/main/java/org/springframework/data/jpa/repository/query/AbstractStringBasedJpaQuery.java

@@ -156,7 +156,7 @@ ReturnedType getReturnedType(ResultProcessor processor) {
 		}
 
 		if ((known != null && !known) || returnedJavaType.isArray() || getMetamodel().isJpaManaged(returnedJavaType)
-				|| !returnedType.needsCustomConstruction()) {
+				|| getMetamodel().isBasicType(returnedJavaType) || !returnedType.needsCustomConstruction()) {
 			if (known == null) {
 				knownProjections.put(returnedJavaType, false);
 			}

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

@@ -19,6 +19,8 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
+import java.util.Set;
+import java.util.HashSet;
 import java.util.concurrent.ConcurrentHashMap;
 
 import jakarta.persistence.Embeddable;
@@ -49,6 +51,7 @@ public class JpaMetamodel {
 
 	private final Lazy<Collection<Class<?>>> managedTypes;
 	private final Lazy<Collection<Class<?>>> jpaEmbeddables;
+	private final Lazy<Collection<Class<?>>> basicTypes;
 
 	/**
 	 * Creates a new {@link JpaMetamodel} for the given JPA {@link Metamodel}.
@@ -71,6 +74,16 @@ private JpaMetamodel(Metamodel metamodel) {
 				.filter(Objects::nonNull)
 				.filter(it -> AnnotatedElementUtils.isAnnotated(it, Embeddable.class))
 				.collect(StreamUtils.toUnmodifiableSet()));
+
+		this.basicTypes = Lazy.of(() -> {
+			if (metamodel instanceof org.hibernate.metamodel.model.domain.JpaMetamodel hibernateMetamodel) {
+				Set<Class<?>> result = new HashSet<>();
+				hibernateMetamodel.getTypeConfiguration().getJavaTypeRegistry()
+						.forEachDescriptor(d -> result.add(d.getJavaTypeClass()));
+				return result;
+			}
+			return Set.of();
+		});
 	}
 
 	public static JpaMetamodel of(Metamodel metamodel) {
@@ -154,4 +167,9 @@ static void clear() {
 				.filter(SingularAttribute::isId) //
 				.findFirst();
 	}
+
+	public boolean isBasicType(Class<?> type) {
+		Assert.notNull(type, "Type must not be null");
+		return basicTypes.get().contains(type);
+	}
 }