Add Kotlin data class components support to BindingReflectionHintsRegistrar

Closes gh-29316

Author: sdeleuze

spring-core/src/main/java/org/springframework/aot/hint/BindingReflectionHintsRegistrar.java

@@ -22,6 +22,8 @@
 import java.util.LinkedHashSet;
 import java.util.Set;
 
+import kotlin.jvm.JvmClassMappingKt;
+import kotlin.reflect.KClass;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 
@@ -101,6 +103,7 @@ else if ((methodName.startsWith("get") && method.getParameterCount() == 0 && met
 					}
 				}
 				if (KotlinDetector.isKotlinType(clazz)) {
+					KotlinDelegate.registerComponentHints(hints, clazz);
 					registerKotlinSerializationHints(hints, clazz);
 				}
 			});
@@ -148,4 +151,22 @@ private void collectReferencedTypes(Set<Class<?>> types, ResolvableType resolvab
 		}
 	}
 
+	/**
+	 * Inner class to avoid a hard dependency on Kotlin at runtime.
+	 */
+	private static class KotlinDelegate {
+
+		public static void registerComponentHints(ReflectionHints hints, Class<?> type) {
+			KClass<?> kClass = JvmClassMappingKt.getKotlinClass(type);
+			if (kClass.isData()) {
+				for (Method method : type.getMethods()) {
+					String methodName = method.getName();
+					if (methodName.startsWith("component") || methodName.equals("copy")) {
+						hints.registerMethod(method, ExecutableMode.INVOKE);
+					}
+				}
+			}
+		}
+	}
+
 }

spring-core/src/test/kotlin/org/springframework/aot/hint/KotlinBindingReflectionHintsRegistrarTests.kt

@@ -19,6 +19,7 @@ package org.springframework.aot.hint
 import org.assertj.core.api.Assertions.assertThat
 import org.assertj.core.api.ThrowingConsumer
 import org.junit.jupiter.api.Test
+import org.springframework.aot.hint.predicate.RuntimeHintsPredicates
 
 /**
  * Tests for Kotlin support in [BindingReflectionHintsRegistrar].
@@ -32,7 +33,7 @@ class KotlinBindingReflectionHintsRegistrarTests {
 	private val hints = RuntimeHints()
 
 	@Test
-	fun `Register type for Kotlinx serialization`() {
+	fun `Register reflection hints for Kotlinx serialization`() {
 		bindingRegistrar.registerReflectionHints(hints.reflection(), SampleSerializableClass::class.java)
 		assertThat(hints.reflection().typeHints()).satisfiesExactlyInAnyOrder(
 			ThrowingConsumer { typeHint: TypeHint ->
@@ -59,7 +60,17 @@ class KotlinBindingReflectionHintsRegistrarTests {
 					})
 			})
 	}
+
+	@Test
+	fun `Register reflection hints for Kotlin data class`() {
+		bindingRegistrar.registerReflectionHints(hints.reflection(), SampleDataClass::class.java)
+		assertThat(RuntimeHintsPredicates.reflection().onMethod(SampleDataClass::class.java, "component1")).accepts(hints)
+		assertThat(RuntimeHintsPredicates.reflection().onMethod(SampleDataClass::class.java, "copy")).accepts(hints)
+		assertThat(RuntimeHintsPredicates.reflection().onMethod(SampleDataClass::class.java, "getName")).accepts(hints)
+	}
 }
 
 @kotlinx.serialization.Serializable
 class SampleSerializableClass(val name: String)
+
+data class SampleDataClass(val name: String)