Merge branch '5.3.x'

spring-aop/src/main/java/org/springframework/aop/framework/AopProxyUtils.java

@@ -128,7 +128,7 @@ static Class<?>[] completeProxiedInterfaces(AdvisedSupport advised, boolean deco
 				if (targetClass.isInterface()) {
 					advised.setInterfaces(targetClass);
 				}
-				else if (Proxy.isProxyClass(targetClass) || isLambda(targetClass)) {
+				else if (Proxy.isProxyClass(targetClass) || ClassUtils.isLambdaClass(targetClass)) {
 					advised.setInterfaces(targetClass.getInterfaces());
 				}
 				specifiedInterfaces = advised.getProxiedInterfaces();
@@ -239,18 +239,4 @@ static Object[] adaptArgumentsIfNecessary(Method method, @Nullable Object[] argu
 		return arguments;
 	}
 
-	/**
-	 * Determine if the supplied {@link Class} is a JVM-generated implementation
-	 * class for a lambda expression or method reference.
-	 * <p>This method makes a best-effort attempt at determining this, based on
-	 * checks that work on modern, main stream JVMs.
-	 * @param clazz the class to check
-	 * @return {@code true} if the class is a lambda implementation class
-	 * @since 5.3.16
-	 */
-	static boolean isLambda(Class<?> clazz) {
-		return (clazz.isSynthetic() && (clazz.getSuperclass() == Object.class) &&
-				(clazz.getInterfaces().length > 0) && clazz.getName().contains("$$Lambda"));
-	}
-
 }

spring-aop/src/main/java/org/springframework/aop/framework/DefaultAopProxyFactory.java

@@ -21,6 +21,7 @@
 
 import org.springframework.aop.SpringProxy;
 import org.springframework.core.NativeDetector;
+import org.springframework.util.ClassUtils;
 
 /**
  * Default {@link AopProxyFactory} implementation, creating either a CGLIB proxy
@@ -60,7 +61,7 @@ public AopProxy createAopProxy(AdvisedSupport config) throws AopConfigException
 				throw new AopConfigException("TargetSource cannot determine target class: " +
 						"Either an interface or a target is required for proxy creation.");
 			}
-			if (targetClass.isInterface() || Proxy.isProxyClass(targetClass) || AopProxyUtils.isLambda(targetClass)) {
+			if (targetClass.isInterface() || Proxy.isProxyClass(targetClass) || ClassUtils.isLambdaClass(targetClass)) {
 				return new JdkDynamicAopProxy(config);
 			}
 			return new ObjenesisCglibAopProxy(config);

spring-aop/src/main/java/org/springframework/aop/framework/autoproxy/AbstractAutoProxyCreator.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 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.
@@ -50,6 +50,7 @@
 import org.springframework.core.SmartClassLoader;
 import org.springframework.lang.Nullable;
 import org.springframework.util.Assert;
+import org.springframework.util.ClassUtils;
 import org.springframework.util.StringUtils;
 
 /**
@@ -85,6 +86,7 @@
  * @author Juergen Hoeller
  * @author Rod Johnson
  * @author Rob Harrop
+ * @author Sam Brannen
  * @since 13.10.2003
  * @see #setInterceptorNames
  * @see #getAdvicesAndAdvisorsForBean
@@ -442,8 +444,8 @@ protected Object createProxy(Class<?> beanClass, @Nullable String beanName,
 		proxyFactory.copyFrom(this);
 
 		if (proxyFactory.isProxyTargetClass()) {
-			// Explicit handling of JDK proxy targets (for introduction advice scenarios)
-			if (Proxy.isProxyClass(beanClass)) {
+			// Explicit handling of JDK proxy targets and lambdas (for introduction advice scenarios)
+			if (Proxy.isProxyClass(beanClass) || ClassUtils.isLambdaClass(beanClass)) {
 				// Must allow for introductions; can't just set interfaces to the proxy's interfaces only.
 				for (Class<?> ifc : beanClass.getInterfaces()) {
 					proxyFactory.addInterface(ifc);

spring-aop/src/test/java/org/springframework/aop/framework/AopProxyUtilsTests.java

@@ -19,7 +19,6 @@
 import java.lang.reflect.Proxy;
 import java.util.Arrays;
 import java.util.List;
-import java.util.function.Supplier;
 
 import org.junit.jupiter.api.Test;
 
@@ -134,61 +133,4 @@ public void testProxiedUserInterfacesWithNoInterface() {
 				AopProxyUtils.proxiedUserInterfaces(proxy));
 	}
 
-	@Test
-	void isLambda() {
-		assertIsLambda(AopProxyUtilsTests.staticLambdaExpression);
-		assertIsLambda(AopProxyUtilsTests::staticStringFactory);
-
-		assertIsLambda(this.instanceLambdaExpression);
-		assertIsLambda(this::instanceStringFactory);
-	}
-
-	@Test
-	void isNotLambda() {
-		assertIsNotLambda(new EnigmaSupplier());
-
-		assertIsNotLambda(new Supplier<String>() {
-			@Override
-			public String get() {
-				return "anonymous inner class";
-			}
-		});
-
-		assertIsNotLambda(new Fake$$LambdaSupplier());
-	}
-
-	private static void assertIsLambda(Supplier<String> supplier) {
-		assertThat(AopProxyUtils.isLambda(supplier.getClass())).isTrue();
-	}
-
-	private static void assertIsNotLambda(Supplier<String> supplier) {
-		assertThat(AopProxyUtils.isLambda(supplier.getClass())).isFalse();
-	}
-
-	private static final Supplier<String> staticLambdaExpression = () -> "static lambda expression";
-
-	private final Supplier<String> instanceLambdaExpression = () -> "instance lambda expressions";
-
-	private static String staticStringFactory() {
-		return "static string factory";
-	}
-
-	private String instanceStringFactory() {
-		return "instance string factory";
-	}
-
-	private static class EnigmaSupplier implements Supplier<String> {
-		@Override
-		public String get() {
-			return "enigma";
-		}
-	}
-
-	private static class Fake$$LambdaSupplier implements Supplier<String> {
-		@Override
-		public String get() {
-			return "fake lambda";
-		}
-	}
-
 }

spring-context/src/test/java/org/springframework/aop/aspectj/autoproxy/AspectJAutoProxyCreatorTests.java

@@ -21,6 +21,8 @@
 import java.lang.reflect.Method;
 import java.util.function.Supplier;
 
+import org.aopalliance.aop.Advice;
+import org.aopalliance.intercept.MethodInvocation;
 import org.aspectj.lang.JoinPoint;
 import org.aspectj.lang.ProceedingJoinPoint;
 import org.aspectj.lang.annotation.Around;
@@ -31,11 +33,17 @@
 import org.junit.jupiter.params.ParameterizedTest;
 import org.junit.jupiter.params.provider.ValueSource;
 
+import org.springframework.aop.ClassFilter;
+import org.springframework.aop.IntroductionAdvisor;
+import org.springframework.aop.IntroductionInterceptor;
 import org.springframework.aop.MethodBeforeAdvice;
+import org.springframework.aop.SpringProxy;
 import org.springframework.aop.aspectj.annotation.AnnotationAwareAspectJAutoProxyCreator;
 import org.springframework.aop.aspectj.annotation.AspectMetadata;
 import org.springframework.aop.config.AopConfigUtils;
+import org.springframework.aop.framework.Advised;
 import org.springframework.aop.framework.ProxyConfig;
+import org.springframework.aop.support.AbstractPointcutAdvisor;
 import org.springframework.aop.support.AopUtils;
 import org.springframework.aop.support.StaticMethodMatcherPointcutAdvisor;
 import org.springframework.beans.PropertyValue;
@@ -52,6 +60,7 @@
 import org.springframework.context.annotation.EnableAspectJAutoProxy;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
 import org.springframework.context.support.GenericApplicationContext;
+import org.springframework.core.DecoratingProxy;
 import org.springframework.core.NestedRuntimeException;
 import org.springframework.core.Ordered;
 import org.springframework.core.annotation.Order;
@@ -304,10 +313,26 @@ public void testWithBeanNameAutoProxyCreator() {
 	@ValueSource(classes = {ProxyTargetClassFalseConfig.class, ProxyTargetClassTrueConfig.class})
 	void lambdaIsAlwaysProxiedWithJdkProxy(Class<?> configClass) {
 		try (ConfigurableApplicationContext context = new AnnotationConfigApplicationContext(configClass)) {
-			Supplier<?> supplier = context.getBean(Supplier.class);
+			@SuppressWarnings("unchecked")
+			Supplier<String> supplier = context.getBean(Supplier.class);
 			assertThat(AopUtils.isAopProxy(supplier)).as("AOP proxy").isTrue();
 			assertThat(AopUtils.isJdkDynamicProxy(supplier)).as("JDK Dynamic proxy").isTrue();
-			assertThat(supplier.get()).asString().isEqualTo("advised: lambda");
+			assertThat(supplier.getClass().getInterfaces())
+				.containsExactlyInAnyOrder(Supplier.class, SpringProxy.class, Advised.class, DecoratingProxy.class);
+			assertThat(supplier.get()).isEqualTo("advised: lambda");
+		}
+	}
+
+	@ParameterizedTest(name = "[{index}] {0}")
+	@ValueSource(classes = {MixinProxyTargetClassFalseConfig.class, MixinProxyTargetClassTrueConfig.class})
+	void lambdaIsAlwaysProxiedWithJdkProxyWithIntroductions(Class<?> configClass) {
+		try (ConfigurableApplicationContext context = new AnnotationConfigApplicationContext(configClass)) {
+			MessageGenerator messageGenerator = context.getBean(MessageGenerator.class);
+			assertThat(AopUtils.isAopProxy(messageGenerator)).as("AOP proxy").isTrue();
+			assertThat(AopUtils.isJdkDynamicProxy(messageGenerator)).as("JDK Dynamic proxy").isTrue();
+			assertThat(messageGenerator.getClass().getInterfaces())
+				.containsExactlyInAnyOrder(MessageGenerator.class, Mixin.class, SpringProxy.class, Advised.class, DecoratingProxy.class);
+			assertThat(messageGenerator.generateMessage()).isEqualTo("mixin: lambda");
 		}
 	}
 
@@ -616,3 +641,79 @@ class ProxyTargetClassFalseConfig extends AbstractProxyTargetClassConfig {
 @EnableAspectJAutoProxy(proxyTargetClass = true)
 class ProxyTargetClassTrueConfig extends AbstractProxyTargetClassConfig {
 }
+
+@FunctionalInterface
+interface MessageGenerator {
+	String generateMessage();
+}
+
+interface Mixin {
+}
+
+class MixinIntroductionInterceptor implements IntroductionInterceptor {
+
+	@Override
+	public Object invoke(MethodInvocation invocation) throws Throwable {
+		return "mixin: " + invocation.proceed();
+	}
+
+	@Override
+	public boolean implementsInterface(Class<?> intf) {
+		return Mixin.class.isAssignableFrom(intf);
+	}
+
+}
+
+@SuppressWarnings("serial")
+class MixinAdvisor extends AbstractPointcutAdvisor implements IntroductionAdvisor {
+
+	@Override
+	public org.springframework.aop.Pointcut getPointcut() {
+		return org.springframework.aop.Pointcut.TRUE;
+	}
+
+	@Override
+	public Advice getAdvice() {
+		return new MixinIntroductionInterceptor();
+	}
+
+	@Override
+	public Class<?>[] getInterfaces() {
+		return new Class[] { Mixin.class };
+	}
+
+	@Override
+	public ClassFilter getClassFilter() {
+		return MessageGenerator.class::isAssignableFrom;
+	}
+
+	@Override
+	public void validateInterfaces() {
+		/* no-op */
+	}
+
+}
+
+abstract class AbstractMixinConfig {
+
+	@Bean
+	MessageGenerator messageGenerator() {
+		return () -> "lambda";
+	}
+
+	@Bean
+	MixinAdvisor mixinAdvisor() {
+		return new MixinAdvisor();
+	}
+
+}
+
+@Configuration(proxyBeanMethods = false)
+@EnableAspectJAutoProxy(proxyTargetClass = false)
+class MixinProxyTargetClassFalseConfig extends AbstractMixinConfig {
+}
+
+@Configuration(proxyBeanMethods = false)
+@EnableAspectJAutoProxy(proxyTargetClass = true)
+class MixinProxyTargetClassTrueConfig extends AbstractMixinConfig {
+}

spring-core/src/main/java/org/springframework/util/ClassUtils.java

@@ -854,6 +854,20 @@ public static boolean isInnerClass(Class<?> clazz) {
 		return (clazz.isMemberClass() && !isStaticClass(clazz));
 	}
 
+	/**
+	 * Determine if the supplied {@link Class} is a JVM-generated implementation
+	 * class for a lambda expression or method reference.
+	 * <p>This method makes a best-effort attempt at determining this, based on
+	 * checks that work on modern, mainstream JVMs.
+	 * @param clazz the class to check
+	 * @return {@code true} if the class is a lambda implementation class
+	 * @since 5.3.19
+	 */
+	public static boolean isLambdaClass(Class<?> clazz) {
+		return (clazz.isSynthetic() && (clazz.getSuperclass() == Object.class) &&
+				(clazz.getInterfaces().length > 0) && clazz.getName().contains("$$Lambda"));
+	}
+
 	/**
 	 * Check whether the given object is a CGLIB proxy.
 	 * @param object the object to check

spring-core/src/test/java/org/springframework/util/ClassUtilsTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2021 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.
@@ -31,6 +31,7 @@
 import java.util.Collections;
 import java.util.List;
 import java.util.Set;
+import java.util.function.Supplier;
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Nested;
@@ -408,6 +409,29 @@ void isPrimitiveOrWrapperWithWrapper(Class<?> type) {
 		assertThat(ClassUtils.isPrimitiveOrWrapper(type)).isTrue();
 	}
 
+	@Test
+	void isLambda() {
+		assertIsLambda(ClassUtilsTests.staticLambdaExpression);
+		assertIsLambda(ClassUtilsTests::staticStringFactory);
+
+		assertIsLambda(this.instanceLambdaExpression);
+		assertIsLambda(this::instanceStringFactory);
+	}
+
+	@Test
+	void isNotLambda() {
+		assertIsNotLambda(new EnigmaSupplier());
+
+		assertIsNotLambda(new Supplier<String>() {
+			@Override
+			public String get() {
+				return "anonymous inner class";
+			}
+		});
+
+		assertIsNotLambda(new Fake$$LambdaSupplier());
+	}
+
 
 	@Nested
 	class GetStaticMethodTests {
@@ -500,4 +524,38 @@ void print(String header, String[] messages, String footer) {
 		}
 	}
 
+	private static void assertIsLambda(Supplier<String> supplier) {
+		assertThat(ClassUtils.isLambdaClass(supplier.getClass())).isTrue();
+	}
+
+	private static void assertIsNotLambda(Supplier<String> supplier) {
+		assertThat(ClassUtils.isLambdaClass(supplier.getClass())).isFalse();
+	}
+
+	private static final Supplier<String> staticLambdaExpression = () -> "static lambda expression";
+
+	private final Supplier<String> instanceLambdaExpression = () -> "instance lambda expressions";
+
+	private static String staticStringFactory() {
+		return "static string factory";
+	}
+
+	private String instanceStringFactory() {
+		return "instance string factory";
+	}
+
+	private static class EnigmaSupplier implements Supplier<String> {
+		@Override
+		public String get() {
+			return "enigma";
+		}
+	}
+
+	private static class Fake$$LambdaSupplier implements Supplier<String> {
+		@Override
+		public String get() {
+			return "fake lambda";
+		}
+	}
+
 }