DATACMNS-1200 - Polishing.

Throw MappingInstantiationException from KotlinClassGeneratingEntityInstantiator if instantiation fails to align behavior with ClassGeneratingEntityInstantiator. Report Kotlin constructor instead of Java constructor if available.

Original pull request: #255.

src/main/java/org/springframework/data/convert/KotlinClassGeneratingEntityInstantiator.java

@@ -20,6 +20,7 @@ import kotlin.reflect.KParameter;
 import kotlin.reflect.jvm.ReflectJvmMapping;
 
 import java.lang.reflect.Constructor;
+import java.util.Arrays;
 import java.util.List;
 import java.util.stream.IntStream;
 
@@ -27,6 +28,7 @@ import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PersistentProperty;
 import org.springframework.data.mapping.PreferredConstructor;
 import org.springframework.data.mapping.PreferredConstructor.Parameter;
+import org.springframework.data.mapping.model.MappingInstantiationException;
 import org.springframework.data.mapping.model.ParameterValueProvider;
 import org.springframework.data.util.ReflectionUtils;
 import org.springframework.lang.Nullable;
@@ -197,7 +199,17 @@ public class KotlinClassGeneratingEntityInstantiator extends ClassGeneratingEnti
 		public <T, E extends PersistentEntity<? extends T, P>, P extends PersistentProperty<P>> T createInstance(E entity,
 				ParameterValueProvider<P> provider) {
 
-			PreferredConstructor<? extends T, P> preferredConstructor = entity.getPersistenceConstructor();
+			Object[] params = extractInvocationArguments(entity.getPersistenceConstructor(), provider);
+
+			try {
+				return (T) instantiator.newInstance(params);
+			} catch (Exception e) {
+				throw new MappingInstantiationException(entity, Arrays.asList(params), e);
+			}
+		}
+
+		private <P extends PersistentProperty<P>, T> Object[] extractInvocationArguments(
+				@Nullable PreferredConstructor<? extends T, P> preferredConstructor, ParameterValueProvider<P> provider) {
 
 			if (preferredConstructor == null) {
 				throw new IllegalArgumentException("PreferredConstructor must not be null!");
@@ -237,7 +249,7 @@ public class KotlinClassGeneratingEntityInstantiator extends ClassGeneratingEnti
 				params[userParameterCount + i] = defaulting[i];
 			}
 
-			return (T) instantiator.newInstance(params);
+			return params;
 		}
 	}
 }

src/main/java/org/springframework/data/mapping/model/MappingInstantiationException.java

@@ -15,6 +15,9 @@
  */
 package org.springframework.data.mapping.model;
 
+import kotlin.reflect.KFunction;
+import kotlin.reflect.jvm.ReflectJvmMapping;
+
 import java.lang.reflect.Constructor;
 import java.util.ArrayList;
 import java.util.List;
@@ -22,6 +25,7 @@ import java.util.Optional;
 
 import org.springframework.data.mapping.PersistentEntity;
 import org.springframework.data.mapping.PreferredConstructor;
+import org.springframework.data.util.ReflectionUtils;
 import org.springframework.lang.Nullable;
 import org.springframework.util.ObjectUtils;
 
@@ -88,12 +92,28 @@ public class MappingInstantiationException extends RuntimeException {
 			}
 
 			return String.format(TEXT_TEMPLATE, it.getType().getName(),
-					constructor.map(c -> c.getConstructor().toString()).orElse("NO_CONSTRUCTOR"), //
+					constructor.map(c -> toString(c)).orElse("NO_CONSTRUCTOR"), //
 					String.join(",", toStringArgs));
 
 		}).orElse(defaultMessage);
 	}
 
+	private static String toString(PreferredConstructor<?, ?> preferredConstructor) {
+
+		Constructor<?> constructor = preferredConstructor.getConstructor();
+
+		if (ReflectionUtils.isSupportedKotlinClass(constructor.getDeclaringClass())) {
+
+			KFunction<?> kotlinFunction = ReflectJvmMapping.getKotlinFunction(constructor);
+
+			if (kotlinFunction != null) {
+				return kotlinFunction.toString();
+			}
+		}
+
+		return constructor.toString();
+	}
+
 	/**
 	 * Returns the type of the entity that was attempted to instantiate.
 	 *