Deprecate SynthesizedAnnotation and related methods

Since Spring no longer adds the SynthesizedAnnotation interface to the
JDK dynamic proxy used to synthesize an annotation, this commit
officially deprecates SynthesizedAnnotation and related methods in
RuntimeHintsUtils.

See gh-29041, gh-29054
Closes gh-29053

Author: sbrannen

spring-beans/src/main/java/org/springframework/beans/factory/annotation/BeanFactoryAnnotationsRuntimeHints.java

@@ -30,6 +30,7 @@
 class BeanFactoryAnnotationsRuntimeHints implements RuntimeHintsRegistrar {
 
 	@Override
+	@SuppressWarnings("deprecation")
 	public void registerHints(RuntimeHints hints, @Nullable ClassLoader classLoader) {
 		RuntimeHintsUtils.registerSynthesizedAnnotation(hints, Qualifier.class);
 	}

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

@@ -66,6 +66,7 @@ public void registerRuntimeHints(RuntimeHints runtimeHints, Class<?>... types) {
 		});
 	}
 
+	@SuppressWarnings("deprecation")
 	private void registerAnnotationIfNecessary(RuntimeHints hints, AnnotatedElement element) {
 		MergedAnnotation<Reflective> reflectiveAnnotation = MergedAnnotations.from(element)
 				.get(Reflective.class);

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

@@ -24,7 +24,6 @@
 import org.springframework.aot.hint.TypeHint.Builder;
 import org.springframework.core.annotation.AliasFor;
 import org.springframework.core.annotation.MergedAnnotation;
-import org.springframework.core.annotation.SynthesizedAnnotation;
 
 /**
  * Utility methods for runtime hints support code.
@@ -49,7 +48,7 @@ public abstract class RuntimeHintsUtils {
 	 * at runtime.
 	 * @param hints the {@link RuntimeHints} instance to use
 	 * @param annotationType the annotation type
-	 * @deprecated as annotation attributes are visible without additional hints
+	 * @deprecated For removal prior to Spring Framework 6.0
 	 */
 	@Deprecated
 	public static void registerAnnotation(RuntimeHints hints, Class<?> annotationType) {
@@ -69,9 +68,13 @@ public static void registerAnnotation(RuntimeHints hints, Class<?> annotationTyp
 	 * that determines if the hints are required.
 	 * @param hints the {@link RuntimeHints} instance to use
 	 * @param annotationType the annotation type
+	 * @deprecated For removal prior to Spring Framework 6.0
 	 */
+	@Deprecated
+	@SuppressWarnings("deprecation")
 	public static void registerSynthesizedAnnotation(RuntimeHints hints, Class<?> annotationType) {
-		hints.proxies().registerJdkProxy(annotationType, SynthesizedAnnotation.class);
+		hints.proxies().registerJdkProxy(annotationType,
+				org.springframework.core.annotation.SynthesizedAnnotation.class);
 	}
 
 	/**
@@ -80,7 +83,9 @@ public static void registerSynthesizedAnnotation(RuntimeHints hints, Class<?> an
 	 * @param hints the {@link RuntimeHints} instance to use
 	 * @param annotation the annotation
 	 * @see #registerSynthesizedAnnotation(RuntimeHints, Class)
+	 * @deprecated For removal prior to Spring Framework 6.0
 	 */
+	@Deprecated
 	public static void registerAnnotationIfNecessary(RuntimeHints hints, MergedAnnotation<?> annotation) {
 		if (annotation.isSynthesizable()) {
 			registerSynthesizedAnnotation(hints, annotation.getType());

spring-core/src/main/java/org/springframework/core/annotation/SynthesizedAnnotation.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2015 the original author or authors.
+ * Copyright 2002-2022 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -23,6 +23,10 @@
  *
  * @author Sam Brannen
  * @since 4.2
+ * @deprecated For removal prior to Spring Framework 6.0; use
+ * {@link AnnotationUtils#isSynthesizedAnnotation(java.lang.annotation.Annotation)}
+ * instead.
  */
+@Deprecated
 public interface SynthesizedAnnotation {
 }

spring-core/src/test/java/org/springframework/aot/hint/annotation/ReflectiveRuntimeHintsRegistrarTests.java

@@ -31,7 +31,6 @@
 import org.springframework.aot.hint.TypeReference;
 import org.springframework.aot.hint.predicate.RuntimeHintsPredicates;
 import org.springframework.core.annotation.AliasFor;
-import org.springframework.core.annotation.SynthesizedAnnotation;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.mockito.Mockito.mock;
@@ -95,11 +94,13 @@ void shouldNotRegisterAnnotationProxyIfNotNeeded() {
 	}
 
 	@Test
+	@SuppressWarnings("deprecation")
 	void shouldRegisterAnnotationProxy() {
 		process(SampleMethodMetaAnnotatedBeanWithAlias.class);
 		RuntimeHints runtimeHints = this.runtimeHints;
-		assertThat(RuntimeHintsPredicates.proxies().forInterfaces(
-				SampleInvoker.class, SynthesizedAnnotation.class)).accepts(runtimeHints);
+		assertThat(RuntimeHintsPredicates.proxies()
+				.forInterfaces(SampleInvoker.class, org.springframework.core.annotation.SynthesizedAnnotation.class))
+					.accepts(runtimeHints);
 	}
 
 	@Test

spring-core/src/test/java/org/springframework/aot/hint/support/RuntimeHintsUtilsTests.java

@@ -28,7 +28,6 @@
 import org.springframework.core.annotation.AliasFor;
 import org.springframework.core.annotation.MergedAnnotation;
 import org.springframework.core.annotation.MergedAnnotations;
-import org.springframework.core.annotation.SynthesizedAnnotation;
 
 import static org.assertj.core.api.Assertions.assertThat;
 
@@ -43,13 +42,15 @@ class RuntimeHintsUtilsTests {
 	private final RuntimeHints hints = new RuntimeHints();
 
 	@Test
+	@SuppressWarnings("deprecation")
 	void registerSynthesizedAnnotation() {
 		RuntimeHintsUtils.registerSynthesizedAnnotation(this.hints, SampleInvoker.class);
 		assertThat(this.hints.proxies().jdkProxies()).singleElement()
 				.satisfies(annotationProxy(SampleInvoker.class));
 	}
 
 	@Test
+	@SuppressWarnings("deprecation")
 	void registerAnnotationIfNecessaryWithNonSynthesizedAnnotation() throws NoSuchFieldException {
 		MergedAnnotation<SampleInvoker> annotation = MergedAnnotations
 				.from(TestBean.class.getField("sampleInvoker")).get(SampleInvoker.class);
@@ -58,6 +59,7 @@ void registerAnnotationIfNecessaryWithNonSynthesizedAnnotation() throws NoSuchFi
 	}
 
 	@Test
+	@SuppressWarnings("deprecation")
 	void registerAnnotationIfNecessaryWithLocalAliases() throws NoSuchFieldException {
 		MergedAnnotation<LocalMapping> annotation = MergedAnnotations
 				.from(TestBean.class.getField("localMapping")).get(LocalMapping.class);
@@ -67,6 +69,7 @@ void registerAnnotationIfNecessaryWithLocalAliases() throws NoSuchFieldException
 	}
 
 	@Test
+	@SuppressWarnings("deprecation")
 	void registerAnnotationIfNecessaryWithMetaAttributeOverride() throws NoSuchFieldException {
 		MergedAnnotation<SampleInvoker> annotation = MergedAnnotations
 				.from(TestBean.class.getField("retryInvoker")).get(SampleInvoker.class);
@@ -76,6 +79,7 @@ void registerAnnotationIfNecessaryWithMetaAttributeOverride() throws NoSuchField
 	}
 
 	@Test
+	@SuppressWarnings("deprecation")
 	void registerAnnotationIfNecessaryWithSynthesizedAttribute() throws NoSuchFieldException {
 		MergedAnnotation<RetryContainer> annotation = MergedAnnotations
 				.from(TestBean.class.getField("retryContainer")).get(RetryContainer.class);
@@ -84,9 +88,11 @@ void registerAnnotationIfNecessaryWithSynthesizedAttribute() throws NoSuchFieldE
 				.satisfies(annotationProxy(RetryContainer.class));
 	}
 
+	@SuppressWarnings("deprecation")
 	private Consumer<JdkProxyHint> annotationProxy(Class<?> type) {
 		return jdkProxyHint -> assertThat(jdkProxyHint.getProxiedInterfaces())
-				.containsExactly(TypeReference.of(type), TypeReference.of(SynthesizedAnnotation.class));
+				.containsExactly(TypeReference.of(type),
+						TypeReference.of(org.springframework.core.annotation.SynthesizedAnnotation.class));
 	}
 
 

spring-messaging/src/main/java/org/springframework/messaging/handler/annotation/MessagingAnnotationsRuntimeHints.java

@@ -34,8 +34,10 @@
 public class MessagingAnnotationsRuntimeHints implements RuntimeHintsRegistrar {
 
 	@Override
+	@SuppressWarnings("deprecation")
 	public void registerHints(RuntimeHints hints, @Nullable ClassLoader classLoader) {
 		Stream.of(Controller.class, Header.class, Headers.class, Payload.class).forEach(annotationType ->
 				RuntimeHintsUtils.registerSynthesizedAnnotation(hints, annotationType));
 	}
+
 }

spring-messaging/src/main/java/org/springframework/messaging/simp/annotation/SimpAnnotationsRuntimeHints.java

@@ -30,7 +30,9 @@
 public class SimpAnnotationsRuntimeHints implements RuntimeHintsRegistrar {
 
 	@Override
+	@SuppressWarnings("deprecation")
 	public void registerHints(RuntimeHints hints, ClassLoader classLoader) {
 		RuntimeHintsUtils.registerSynthesizedAnnotation(hints, SendToUser.class);
 	}
+
 }

spring-test/src/main/java/org/springframework/test/context/aot/hint/TestContextRuntimeHints.java

@@ -169,7 +169,7 @@ private static List<TypeReference> listOf(String... classNames) {
 	}
 
 	@SafeVarargs
-	@SuppressWarnings("unchecked")
+	@SuppressWarnings({ "unchecked", "deprecation" })
 	private static void registerSynthesizedAnnotations(RuntimeHints runtimeHints, Class<? extends Annotation>... annotationTypes) {
 		for (Class<? extends Annotation> annotationType : annotationTypes) {
 			registerAnnotation(runtimeHints.reflection(), annotationType);

spring-test/src/test/java/org/springframework/test/context/aot/TestContextAotGeneratorTests.java

@@ -36,7 +36,6 @@
 import org.springframework.context.ApplicationContext;
 import org.springframework.context.ApplicationContextInitializer;
 import org.springframework.context.ConfigurableApplicationContext;
-import org.springframework.core.annotation.SynthesizedAnnotation;
 import org.springframework.javapoet.ClassName;
 import org.springframework.test.context.MergedContextConfiguration;
 import org.springframework.test.context.aot.samples.basic.BasicSpringJupiterSharedConfigTests;
@@ -210,9 +209,11 @@ private static void assertAnnotationRegistered(RuntimeHints runtimeHints, Class<
 			.anySatisfy(annotationProxy(annotationType));
 	}
 
+	@SuppressWarnings("deprecation")
 	private static Consumer<JdkProxyHint> annotationProxy(Class<? extends Annotation> type) {
 		return jdkProxyHint -> assertThat(jdkProxyHint.getProxiedInterfaces())
-				.containsExactly(TypeReference.of(type), TypeReference.of(SynthesizedAnnotation.class));
+				.containsExactly(TypeReference.of(type),
+						TypeReference.of(org.springframework.core.annotation.SynthesizedAnnotation.class));
 	}
 
 	@Test

spring-tx/src/main/java/org/springframework/transaction/annotation/TransactionRuntimeHints.java

@@ -35,6 +35,7 @@
 class TransactionRuntimeHints implements RuntimeHintsRegistrar {
 
 	@Override
+	@SuppressWarnings("deprecation")
 	public void registerHints(RuntimeHints hints, ClassLoader classLoader) {
 		RuntimeHintsUtils.registerSynthesizedAnnotation(hints, Transactional.class);
 		hints.reflection().registerTypes(TypeReference.listOf(

spring-web/src/main/java/org/springframework/web/bind/annotation/WebAnnotationsRuntimeHintsRegistrar.java

@@ -34,6 +34,7 @@
 public final class WebAnnotationsRuntimeHintsRegistrar implements RuntimeHintsRegistrar {
 
 	@Override
+	@SuppressWarnings("deprecation")
 	public void registerHints(RuntimeHints hints, @Nullable ClassLoader classLoader) {
 		Stream.of(Controller.class, ControllerAdvice.class, CookieValue.class,
 						CrossOrigin.class, MatrixVariable.class, ModelAttribute.class,