Add support for @Transactional in native images

This commit introduces a TransactionBeanRegistrationAotProcessor
in charge of creating the required proxy and reflection hints
when @Transactional is detected on beans.

It also refines DefaultAopProxyFactory to throw an exception
when a subclass-based proxy is created in native images
since that's unsupported for now (see gh-28115 related issue).

Closes gh-28717

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

@@ -0,0 +1,99 @@
+/*
+ * 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.
+ * You may obtain a copy of the License at
+ *
+ *      https://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.springframework.transaction.annotation;
+
+import java.lang.reflect.AnnotatedElement;
+import java.util.LinkedHashSet;
+import java.util.Set;
+
+import org.springframework.aop.SpringProxy;
+import org.springframework.aop.framework.Advised;
+import org.springframework.aot.generate.GenerationContext;
+import org.springframework.aot.hint.MemberCategory;
+import org.springframework.aot.hint.RuntimeHints;
+import org.springframework.beans.factory.aot.BeanRegistrationAotContribution;
+import org.springframework.beans.factory.aot.BeanRegistrationAotProcessor;
+import org.springframework.beans.factory.aot.BeanRegistrationCode;
+import org.springframework.beans.factory.support.RegisteredBean;
+import org.springframework.core.DecoratingProxy;
+import org.springframework.core.annotation.MergedAnnotations;
+import org.springframework.util.ClassUtils;
+import org.springframework.util.ReflectionUtils;
+
+/**
+ * AOT {@code BeanRegistrationAotProcessor} that detects the presence of
+ * {@link Transactional @Transactional} on annotated elements and creates
+ * the required proxy and reflection hints.
+ *
+ * @author Sebastien Deleuze
+ * @since 6.0
+ * @see TransactionRuntimeHintsRegistrar
+ */
+public class TransactionBeanRegistrationAotProcessor implements BeanRegistrationAotProcessor {
+
+	private final static String JAKARTA_TRANSACTIONAL_CLASS_NAME = "jakarta.transaction.Transactional";
+
+	@Override
+	public BeanRegistrationAotContribution processAheadOfTime(RegisteredBean registeredBean) {
+		Class<?> beanClass = registeredBean.getBeanClass();
+		if (isTransactional(beanClass)) {
+			return new TransactionBeanRegistrationAotContribution(beanClass);
+		}
+		return null;
+	}
+
+	private boolean isTransactional(Class<?> beanClass) {
+		Set<AnnotatedElement> elements = new LinkedHashSet<>();
+		elements.add(beanClass);
+		ReflectionUtils.doWithMethods(beanClass, elements::add);
+		for (Class<?> interfaceClass : ClassUtils.getAllInterfacesForClass(beanClass)) {
+			elements.add(interfaceClass);
+			ReflectionUtils.doWithMethods(interfaceClass, elements::add);
+		}
+		return elements.stream().anyMatch(element -> {
+			MergedAnnotations mergedAnnotations = MergedAnnotations.from(element, MergedAnnotations.SearchStrategy.TYPE_HIERARCHY);
+			return mergedAnnotations.isPresent(Transactional.class) || mergedAnnotations.isPresent(JAKARTA_TRANSACTIONAL_CLASS_NAME);
+		});
+	}
+
+	private static class TransactionBeanRegistrationAotContribution implements BeanRegistrationAotContribution {
+
+		private Class<?> beanClass;
+
+		public TransactionBeanRegistrationAotContribution(Class<?> beanClass) {
+			this.beanClass = beanClass;
+		}
+
+		@Override
+		public void applyTo(GenerationContext generationContext, BeanRegistrationCode beanRegistrationCode) {
+			RuntimeHints runtimeHints = generationContext.getRuntimeHints();
+			LinkedHashSet<Class<?>> interfaces = new LinkedHashSet<>();
+			Class<?>[] proxyInterfaces = ClassUtils.getAllInterfacesForClass(this.beanClass);
+			if (proxyInterfaces.length == 0) {
+				return;
+			}
+			for (Class<?> proxyInterface : proxyInterfaces) {
+				interfaces.add(proxyInterface);
+				runtimeHints.reflection().registerType(proxyInterface, builder -> builder.withMembers(MemberCategory.INVOKE_DECLARED_METHODS));
+			}
+			interfaces.add(SpringProxy.class);
+			interfaces.add(Advised.class);
+			interfaces.add(DecoratingProxy.class);
+			runtimeHints.proxies().registerJdkProxy(interfaces.toArray(Class[]::new));
+		}
+	}
+}

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

@@ -30,6 +30,7 @@ import static java.util.Arrays.asList;
  *
  * @author Sebastien Deleuze
  * @since 6.0
+ * @see TransactionBeanRegistrationAotProcessor
  */
 public class TransactionRuntimeHintsRegistrar implements RuntimeHintsRegistrar {