Fix too restrictive entity callback matching.

We now properly support generic entity callbacks defined via lambda declarations.

Fixes #2822.

Author: odrotbohm

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

@@ -33,9 +33,7 @@
 import org.springframework.beans.factory.config.ConfigurableBeanFactory;
 import org.springframework.beans.factory.support.BeanDefinitionRegistry;
 import org.springframework.core.ResolvableType;
-import org.springframework.core.ResolvableTypeProvider;
 import org.springframework.core.annotation.AnnotationAwareOrderComparator;
-import org.springframework.lang.NonNull;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
 import org.springframework.util.ClassUtils;
@@ -291,12 +289,9 @@ static boolean supportsEvent(ResolvableType callbackType, ResolvableType entityT
 	static boolean supportsEvent(EntityCallback<?> callback, ResolvableType entityType,
 			ResolvableType callbackType) {
 
-		ResolvableType callbackInstanceType = callback instanceof EntityCallbackAdapter<?> provider
-				? provider.getResolvableType()
-				: ResolvableType.forInstance(callback);
-
-		return supportsEvent(callbackInstanceType, entityType)
-				&& callbackType.isAssignableFrom(callbackInstanceType);
+		return callback instanceof EntityCallbackAdapter<?> provider
+				? provider.supports(callbackType, entityType)
+				: callbackType.isInstance(callback) && supportsEvent(ResolvableType.forInstance(callback), entityType);
 	}
 
 	/**
@@ -346,12 +341,10 @@ void discoverEntityCallbacks(BeanFactory beanFactory) {
 	 * @author Oliver Drotbohm
 	 */
 	private static record EntityCallbackAdapter<T>(EntityCallback<T> delegate, ResolvableType type)
-			implements EntityCallback<T>, ResolvableTypeProvider {
+			implements EntityCallback<T> {
 
-		@NonNull
-		@Override
-		public ResolvableType getResolvableType() {
-			return type;
+		boolean supports(ResolvableType callbackType, ResolvableType entityType) {
+			return callbackType.isInstance(delegate) && supportsEvent(type, entityType);
 		}
 	}
 

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

@@ -169,8 +169,7 @@ void skipsInvocationUsingJava18ReflectiveTypeRejection() {
 	@Test // DATACMNS-1467
 	void detectsMultipleCallbacksWithinOneClass() {
 
-		var ctx = new AnnotationConfigApplicationContext(
-				MultipleCallbacksInOneClassConfig.class);
+		var ctx = new AnnotationConfigApplicationContext(MultipleCallbacksInOneClassConfig.class);
 
 		var callbacks = new DefaultEntityCallbacks(ctx);
 
@@ -184,6 +183,17 @@ void detectsMultipleCallbacksWithinOneClass() {
 		assertThat(ctx.getBean("callbacks", MultipleCallbacks.class).invocations).containsExactly("save", "convert");
 	}
 
+	@Test // GH-2822
+	void genericCallbackDiscoveredForObjectDeclaration() {
+
+		var ctx = new AnnotationConfigApplicationContext(SomeConfiguration.class);
+		var callbacks = new DefaultEntityCallbacks(ctx);
+
+		callbacks.callback(BeforeSaveCallback.class, new PersonDocument(null, "Walter", null));
+
+		assertThat(ctx.getBean(SomeConfiguration.class).invoked).isTrue();
+	}
+
 	@Configuration
 	static class MyConfig {
 
@@ -312,4 +322,18 @@ public Person onBeforeConvert(Person object) {
 
 	}
 
+	// GH-2822
+	@Configuration
+	static class SomeConfiguration {
+
+		boolean invoked = false;
+
+		@Bean
+		BeforeSaveCallback<Object> someGenericCallback() {
+			return it -> {
+				this.invoked = true;
+				return it;
+			};
+		}
+	}
 }