Gracefully skip non-assignable reactive lambda callbacks on Java 18+.

Closes #2808, #2809.

Author: michael-simons

src/main/java/org/springframework/data/mapping/callback/DefaultReactiveEntityCallbacks.java

@@ -37,6 +37,7 @@
  *
  * @author Mark Paluch
  * @author Christoph Strobl
+ * @author Michael J. Simons
  */
 class DefaultReactiveEntityCallbacks implements ReactiveEntityCallbacks {
 
@@ -112,7 +113,7 @@ public <T> Mono<T> invokeCallback(EntityCallback<T> callback, T entity,
 
 				throw new IllegalArgumentException(
 						String.format("Callback invocation on %s returned null value for %s", callback.getClass(), entity));
-			} catch (ClassCastException ex) {
+			} catch (IllegalArgumentException | ClassCastException ex) {
 
 				String msg = ex.getMessage();
 				if (msg == null || EntityCallbackInvoker.matchesClassCastMessage(msg, entity.getClass())) {

src/test/java/org/springframework/data/mapping/callback/DefaultReactiveEntityCallbacksUnitTests.java

@@ -17,6 +17,9 @@
 
 import static org.assertj.core.api.Assertions.*;
 
+import java.util.ArrayList;
+import java.util.List;
+
 import reactor.core.publisher.Mono;
 import reactor.test.StepVerifier;
 
@@ -26,6 +29,7 @@
 import org.springframework.context.annotation.Configuration;
 import org.springframework.data.mapping.Person;
 import org.springframework.data.mapping.PersonDocument;
+import org.springframework.data.mapping.PersonNoId;
 import org.springframework.data.mapping.callback.CapturingEntityCallback.FirstCallback;
 import org.springframework.data.mapping.callback.CapturingEntityCallback.SecondCallback;
 import org.springframework.data.mapping.callback.CapturingEntityCallback.ThirdCallback;
@@ -35,6 +39,7 @@
  *
  * @author Mark Paluch
  * @author Christoph Strobl
+ * @author Michael J. Simons
  */
 class DefaultReactiveEntityCallbacksUnitTests {
 
@@ -124,6 +129,24 @@ void errorsOnNullValueReturnedByCallbackEntity() {
 		assertThat(third.capturedValues()).isEmpty();
 	}
 
+	@Test // GH-2808
+	void skipsInvocationUsingJava18ReflectiveTypeRejection() {
+
+		DefaultReactiveEntityCallbacks callbacks = new DefaultReactiveEntityCallbacks();
+		callbacks.addEntityCallback(new DefaultEntityCallbacksUnitTests.Java18ClassCastStyle());
+
+		Person person = new PersonNoId(42, "Walter", "White");
+		List<Person> capturedPerson = new ArrayList<>();
+
+		callbacks.callback(DefaultEntityCallbacksUnitTests.BeforeConvertCallback.class, person) //
+			.as(StepVerifier::create)
+			.recordWith(() -> capturedPerson)
+			.expectNextCount(1)
+			.verifyComplete();
+
+		assertThat(capturedPerson.get(0)).isSameAs(person);
+	}
+
 	@Configuration
 	static class MyConfig {