Restore ability to return original method for proxy-derived method

Closes gh-32365

Author: jhoeller

spring-aop/src/test/java/org/springframework/aop/support/AopUtilsTests.java

@@ -17,16 +17,19 @@
 package org.springframework.aop.support;
 
 import java.lang.reflect.Method;
+import java.util.List;
 
 import org.junit.jupiter.api.Test;
 
 import org.springframework.aop.ClassFilter;
 import org.springframework.aop.MethodMatcher;
 import org.springframework.aop.Pointcut;
+import org.springframework.aop.framework.ProxyFactory;
 import org.springframework.aop.interceptor.ExposeInvocationInterceptor;
 import org.springframework.aop.target.EmptyTargetSource;
 import org.springframework.aop.testfixture.interceptor.NopInterceptor;
 import org.springframework.beans.testfixture.beans.TestBean;
+import org.springframework.core.ResolvableType;
 import org.springframework.core.testfixture.io.SerializationTestUtils;
 import org.springframework.lang.Nullable;
 import org.springframework.util.ReflectionUtils;
@@ -37,6 +40,7 @@
  * @author Rod Johnson
  * @author Chris Beams
  * @author Sebastien Deleuze
+ * @author Juergen Hoeller
  */
 class AopUtilsTests {
 
@@ -99,4 +103,36 @@ void testInvokeJoinpointUsingReflection() throws Throwable {
 		assertThat(result).isEqualTo(name);
 	}
 
+	@Test  // gh-32365
+	void mostSpecificMethodBetweenJdkProxyAndTarget() throws Exception {
+		Class<?> proxyClass = new ProxyFactory(new WithInterface()).getProxyClass(getClass().getClassLoader());
+		Method specificMethod = AopUtils.getMostSpecificMethod(proxyClass.getMethod("handle", List.class), WithInterface.class);
+		assertThat(ResolvableType.forMethodParameter(specificMethod, 0).getGeneric().toClass()).isEqualTo(String.class);
+	}
+
+	@Test  // gh-32365
+	void mostSpecificMethodBetweenCglibProxyAndTarget() throws Exception {
+		Class<?> proxyClass = new ProxyFactory(new WithoutInterface()).getProxyClass(getClass().getClassLoader());
+		Method specificMethod = AopUtils.getMostSpecificMethod(proxyClass.getMethod("handle", List.class), WithoutInterface.class);
+		assertThat(ResolvableType.forMethodParameter(specificMethod, 0).getGeneric().toClass()).isEqualTo(String.class);
+	}
+
+
+	interface ProxyInterface {
+
+		void handle(List<String> list);
+	}
+
+	static class WithInterface implements ProxyInterface {
+
+		public void handle(List<String> list) {
+		}
+	}
+
+	static class WithoutInterface {
+
+		public void handle(List<String> list) {
+		}
+	}
+
 }

spring-core/src/main/java/org/springframework/core/BridgeMethodResolver.java

@@ -17,6 +17,7 @@
 package org.springframework.core;
 
 import java.lang.reflect.Method;
+import java.lang.reflect.Proxy;
 import java.lang.reflect.Type;
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -86,7 +87,10 @@ public static Method findBridgedMethod(Method bridgeMethod) {
 	 * @see org.springframework.util.ClassUtils#getMostSpecificMethod
 	 */
 	public static Method getMostSpecificMethod(Method bridgeMethod, @Nullable Class<?> targetClass) {
-		if (targetClass != null && !bridgeMethod.getDeclaringClass().isAssignableFrom(targetClass)) {
+		if (targetClass != null &&
+				!ClassUtils.getUserClass(bridgeMethod.getDeclaringClass()).isAssignableFrom(targetClass) &&
+				!Proxy.isProxyClass(bridgeMethod.getDeclaringClass())) {
+			// From a different class hierarchy, and not a JDK or CGLIB proxy either -> return as-is.
 			return bridgeMethod;
 		}