Polishing.

Guard usage of KotlinReflectUtils with type presence check.
Extend tests to cover primitive arrays.
Move methods from KotlinValueUtils to KotlinReflectUtils.
Move copy value cache to KotlinCopyMethod.

Original Pull Request: #2866

src/main/java/org/springframework/data/util/KotlinReflectionUtils.java

@@ -37,7 +37,7 @@ import org.springframework.lang.Nullable;
 
 /**
  * Reflection utility methods specific to Kotlin reflection. Requires Kotlin classes to be present to avoid linkage
- * errors.
+ * errors - ensure to guard usage with {@link KotlinDetector#isKotlinPresent()}.
  *
  * @author Mark Paluch
  * @author Christoph Strobl
@@ -132,6 +132,42 @@ public final class KotlinReflectionUtils {
 		return JvmClassMappingKt.getJavaClass(KTypesJvm.getJvmErasure(kotlinFunction.getReturnType()));
 	}
 
+	/**
+	 * Returns whether the given {@link KType} is a {@link KClass#isValue() value} class.
+	 *
+	 * @param type the kotlin type to inspect.
+	 * @return {@code true} the type is a value class.
+	 * @since 3.2
+	 */
+	public static boolean isValueClass(KType type) {
+
+		return type.getClassifier() instanceof KClass<?> kc && kc.isValue();
+	}
+
+	/**
+	 * Returns whether the given class makes uses Kotlin {@link KClass#isValue() value} classes.
+	 *
+	 * @param type the kotlin type to inspect.
+	 * @return {@code true} when at least one property uses Kotlin value classes.
+	 * @since 3.2
+	 */
+	public static boolean hasValueClassProperty(Class<?> type) {
+
+		if (!KotlinDetector.isKotlinType(type)) {
+			return false;
+		}
+
+		KClass<?> kotlinClass = JvmClassMappingKt.getKotlinClass(type);
+
+		for (KCallable<?> member : kotlinClass.getMembers()) {
+			if (member instanceof KProperty<?> kp && isValueClass(kp.getReturnType())) {
+				return true;
+			}
+		}
+
+		return false;
+	}
+
 	/**
 	 * Returns {@literal} whether the given {@link MethodParameter} is nullable. Its declaring method can reference a
 	 * Kotlin function, property or interface property.

src/main/java/org/springframework/data/util/Predicates.java

@@ -21,6 +21,7 @@ import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
 import java.util.function.Predicate;
 
+import org.springframework.core.KotlinDetector;
 import org.springframework.util.Assert;
 
 /**
@@ -45,7 +46,7 @@ public interface Predicates {
 	Predicate<Member> IS_PUBLIC = member -> Modifier.isPublic(member.getModifiers());
 	Predicate<Member> IS_SYNTHETIC = Member::isSynthetic;
 
-	Predicate<Class<?>> IS_KOTLIN = KotlinReflectionUtils::isSupportedKotlinClass;
+	Predicate<Class<?>> IS_KOTLIN =  KotlinDetector.isKotlinPresent() ? KotlinReflectionUtils::isSupportedKotlinClass : type -> false;
 	Predicate<Member> IS_STATIC = member -> Modifier.isStatic(member.getModifiers());
 
 	Predicate<Method> IS_BRIDGE_METHOD = Method::isBridge;