Merge branch '5.3.x'

spring-aop/src/main/java/org/springframework/aop/framework/AopProxyUtils.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.
@@ -43,6 +43,7 @@ import org.springframework.util.ObjectUtils;
  *
  * @author Rod Johnson
  * @author Juergen Hoeller
+ * @author Sam Brannen
  * @see org.springframework.aop.support.AopUtils
  */
 public abstract class AopProxyUtils {
@@ -127,7 +128,7 @@ public abstract class AopProxyUtils {
 				if (targetClass.isInterface()) {
 					advised.setInterfaces(targetClass);
 				}
-				else if (Proxy.isProxyClass(targetClass)) {
+				else if (Proxy.isProxyClass(targetClass) || isLambda(targetClass)) {
 					advised.setInterfaces(targetClass.getInterfaces());
 				}
 				specifiedInterfaces = advised.getProxiedInterfaces();
@@ -238,4 +239,18 @@ public abstract class AopProxyUtils {
 		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 5.2.16
+	 */
+	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

@@ -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.
@@ -40,6 +40,7 @@ import org.springframework.core.NativeDetector;
  * @author Rod Johnson
  * @author Juergen Hoeller
  * @author Sebastien Deleuze
+ * @author Sam Brannen
  * @since 12.03.2004
  * @see AdvisedSupport#setOptimize
  * @see AdvisedSupport#setProxyTargetClass
@@ -59,7 +60,7 @@ public class DefaultAopProxyFactory implements AopProxyFactory, Serializable {
 				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)) {
+			if (targetClass.isInterface() || Proxy.isProxyClass(targetClass) || AopProxyUtils.isLambda(targetClass)) {
 				return new JdkDynamicAopProxy(config);
 			}
 			return new ObjenesisCglibAopProxy(config);

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2019 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.
@@ -19,6 +19,7 @@ package org.springframework.aop.framework;
 import java.lang.reflect.Proxy;
 import java.util.Arrays;
 import java.util.List;
+import java.util.function.Supplier;
 
 import org.junit.jupiter.api.Test;
 
@@ -32,6 +33,7 @@ import static org.assertj.core.api.Assertions.assertThatIllegalArgumentException
 /**
  * @author Rod Johnson
  * @author Chris Beams
+ * @author Sam Brannen
  */
 public class AopProxyUtilsTests {
 
@@ -132,4 +134,61 @@ public class AopProxyUtilsTests {
 				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

@@ -19,6 +19,7 @@ package org.springframework.aop.aspectj.autoproxy;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.lang.reflect.Method;
+import java.util.function.Supplier;
 
 import org.aspectj.lang.JoinPoint;
 import org.aspectj.lang.ProceedingJoinPoint;
@@ -27,6 +28,8 @@ import org.aspectj.lang.annotation.Aspect;
 import org.aspectj.lang.annotation.Before;
 import org.aspectj.lang.annotation.Pointcut;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.ValueSource;
 
 import org.springframework.aop.MethodBeforeAdvice;
 import org.springframework.aop.aspectj.annotation.AnnotationAwareAspectJAutoProxyCreator;
@@ -42,6 +45,11 @@ import org.springframework.beans.factory.support.RootBeanDefinition;
 import org.springframework.beans.testfixture.beans.ITestBean;
 import org.springframework.beans.testfixture.beans.TestBean;
 import org.springframework.context.ApplicationContext;
+import org.springframework.context.ConfigurableApplicationContext;
+import org.springframework.context.annotation.AnnotationConfigApplicationContext;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.context.annotation.EnableAspectJAutoProxy;
 import org.springframework.context.support.ClassPathXmlApplicationContext;
 import org.springframework.context.support.GenericApplicationContext;
 import org.springframework.core.NestedRuntimeException;
@@ -292,6 +300,16 @@ public class AspectJAutoProxyCreatorTests {
 		assertThat(tb.getAge()).isEqualTo(68);
 	}
 
+	@ParameterizedTest(name = "[{index}] {0}")
+	@ValueSource(classes = {ProxyTargetClassFalseConfig.class, ProxyTargetClassTrueConfig.class})
+	void lambdaIsAlwaysProxiedWithJdkProxy(Class<?> configClass) {
+		try (ConfigurableApplicationContext context = new AnnotationConfigApplicationContext(configClass)) {
+			Supplier<?> 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");
+		}
+	}
 
 	/**
 	 * Returns a new {@link ClassPathXmlApplicationContext} for the file ending in <var>fileSuffix</var>.
@@ -566,3 +584,35 @@ class TestBeanAdvisor extends StaticMethodMatcherPointcutAdvisor {
 	}
 
 }
+
+abstract class AbstractProxyTargetClassConfig {
+
+	@Bean
+	Supplier<String> stringSupplier() {
+		return () -> "lambda";
+	}
+
+	@Bean
+	SupplierAdvice supplierAdvice() {
+		return new SupplierAdvice();
+	}
+
+	@Aspect
+	static class SupplierAdvice {
+
+		@Around("execution(public * org.springframework.aop.aspectj.autoproxy..*.*(..))")
+		Object aroundSupplier(ProceedingJoinPoint joinPoint) throws Throwable {
+			return "advised: " + joinPoint.proceed();
+		}
+	}
+}
+
+@Configuration(proxyBeanMethods = false)
+@EnableAspectJAutoProxy(proxyTargetClass = false)
+class ProxyTargetClassFalseConfig extends AbstractProxyTargetClassConfig {
+}
+
+@Configuration(proxyBeanMethods = false)
+@EnableAspectJAutoProxy(proxyTargetClass = true)
+class ProxyTargetClassTrueConfig extends AbstractProxyTargetClassConfig {
+}

src/checkstyle/checkstyle.xml

@@ -51,7 +51,7 @@
 
 		<!-- Type Names -->
 		<module name="TypeName">
-			<property name="format" value="^[A-Z][a-zA-Z0-9_]*(?&lt;!Test)$" />
+			<property name="format" value="^[A-Z][a-zA-Z0-9_$]*(?&lt;!Test)$" />
 			<property name="tokens" value="CLASS_DEF" />
 			<message key="name.invalidPattern"
 				value="Class name ''{0}'' must not end with ''Test'' (checked pattern ''{1}'')." />