Consistent handling of undeclared checked exceptions in CGLIB proxies

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

@@ -19,7 +19,6 @@
 import java.io.Serializable;
 import java.lang.reflect.Method;
 import java.lang.reflect.Modifier;
-import java.lang.reflect.UndeclaredThrowableException;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -54,7 +53,6 @@
 import org.springframework.util.ClassUtils;
 import org.springframework.util.CollectionUtils;
 import org.springframework.util.ObjectUtils;
-import org.springframework.util.ReflectionUtils;
 
 /**
  * CGLIB-based {@link AopProxy} implementation for the Spring AOP framework.
@@ -761,27 +759,7 @@ public CglibMethodInvocation(Object proxy, @Nullable Object target, Method metho
 		@Override
 		@Nullable
 		public Object proceed() throws Throwable {
-			try {
 				return super.proceed();
-			}
-			catch (RuntimeException ex) {
-				throw ex;
-			}
-			catch (Exception ex) {
-				if (ReflectionUtils.declaresException(getMethod(), ex.getClass()) ||
-						KotlinDetector.isKotlinType(getMethod().getDeclaringClass())) {
-					// Propagate original exception if declared on the target method
-					// (with callers expecting it). Always propagate it for Kotlin code
-					// since checked exceptions do not have to be explicitly declared there.
-					throw ex;
-				}
-				else {
-					// Checked exception thrown in the interceptor but not declared on the
-					// target method signature -> apply an UndeclaredThrowableException,
-					// aligned with standard JDK dynamic proxy behavior.
-					throw new UndeclaredThrowableException(ex);
-				}
-			}
 		}
 	}
 

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

@@ -0,0 +1,211 @@
+/*
+ * Copyright 2002-2024 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.aop.framework;
+
+import java.io.Serial;
+import java.lang.reflect.Proxy;
+import java.lang.reflect.UndeclaredThrowableException;
+import java.util.Objects;
+
+import org.aopalliance.intercept.MethodInterceptor;
+import org.assertj.core.api.WithAssertions;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Nested;
+import org.junit.jupiter.api.Test;
+import org.mockito.Mockito;
+import org.mockito.stubbing.Answer;
+
+import org.springframework.cglib.proxy.Enhancer;
+import org.springframework.lang.Nullable;
+
+import static org.mockito.BDDMockito.doAnswer;
+import static org.mockito.BDDMockito.doThrow;
+import static org.mockito.BDDMockito.mock;
+
+abstract class ProxyExceptionHandlingTests implements WithAssertions {
+
+	private static final RuntimeException uncheckedException = new RuntimeException();
+	private static final DeclaredCheckedException declaredCheckedException = new DeclaredCheckedException();
+	private static final UndeclaredCheckedException undeclaredCheckedException = new UndeclaredCheckedException();
+
+	protected final MyClass target = mock(MyClass.class);
+	protected final ProxyFactory proxyFactory = new ProxyFactory(target);
+
+	@Nullable
+	protected MyInterface proxy;
+	@Nullable
+	private Throwable throwableSeenByCaller;
+
+	static class ObjenesisCglibAopProxyTests extends ProxyExceptionHandlingTests {
+		@BeforeEach
+		void beforeEach() {
+			proxyFactory.setProxyTargetClass(true);
+		}
+
+		@Override
+		protected void assertProxyType(Object proxy) {
+			assertThat(Enhancer.isEnhanced(proxy.getClass())).isTrue();
+		}
+	}
+
+	static class JdkAopProxyTests extends ProxyExceptionHandlingTests {
+		@Override
+		protected void assertProxyType(Object proxy) {
+			assertThat(Proxy.isProxyClass(proxy.getClass())).isTrue();
+		}
+	}
+
+	protected void assertProxyType(Object proxy) {
+	}
+
+	@BeforeEach
+	void beforeEach() {
+		Mockito.clearInvocations(target);
+	}
+
+	@Nested
+	class WhenThereIsOneInterceptor {
+
+		@Nullable
+		private Throwable throwableSeenByInterceptor;
+
+		@BeforeEach
+		void beforeEach() {
+			proxyFactory.addAdvice(captureThrowable());
+
+			proxy = (MyInterface) proxyFactory.getProxy();
+
+			assertProxyType(proxy);
+		}
+
+		@Test
+		void targetThrowsUndeclaredCheckedException() throws DeclaredCheckedException {
+			doAnswer(sneakyThrow(undeclaredCheckedException)).when(target).doSomething();
+
+			invokeProxy();
+
+			assertThat(throwableSeenByInterceptor).isSameAs(undeclaredCheckedException);
+			assertThat(throwableSeenByCaller)
+					.isInstanceOf(UndeclaredThrowableException.class)
+					.hasCauseReference(undeclaredCheckedException);
+		}
+
+		@Test
+		void targetThrowsDeclaredCheckedException() throws DeclaredCheckedException {
+			doThrow(declaredCheckedException).when(target).doSomething();
+
+			invokeProxy();
+
+			assertThat(throwableSeenByInterceptor).isSameAs(declaredCheckedException);
+			assertThat(throwableSeenByCaller).isSameAs(declaredCheckedException);
+		}
+
+		@Test
+		void targetThrowsUncheckedException() throws DeclaredCheckedException {
+			doThrow(uncheckedException).when(target).doSomething();
+
+			invokeProxy();
+
+			assertThat(throwableSeenByInterceptor).isSameAs(uncheckedException);
+			assertThat(throwableSeenByCaller).isSameAs(uncheckedException);
+		}
+
+		private MethodInterceptor captureThrowable() {
+			return invocation -> {
+				try {
+					return invocation.proceed();
+				}
+				catch (Exception e) {
+					throwableSeenByInterceptor = e;
+					throw e;
+				}
+			};
+		}
+	}
+
+	@Nested
+	class WhenThereAreNoInterceptors {
+
+		@BeforeEach
+		void beforeEach() {
+			proxy = (MyInterface) proxyFactory.getProxy();
+
+			assertProxyType(proxy);
+		}
+
+		@Test
+		void targetThrowsUndeclaredCheckedException() throws DeclaredCheckedException {
+			doAnswer(sneakyThrow(undeclaredCheckedException)).when(target).doSomething();
+
+			invokeProxy();
+
+			assertThat(throwableSeenByCaller)
+					.isInstanceOf(UndeclaredThrowableException.class)
+					.hasCauseReference(undeclaredCheckedException);
+		}
+
+		@Test
+		void targetThrowsDeclaredCheckedException() throws DeclaredCheckedException {
+			doThrow(declaredCheckedException).when(target).doSomething();
+
+			invokeProxy();
+
+			assertThat(throwableSeenByCaller).isSameAs(declaredCheckedException);
+		}
+
+		@Test
+		void targetThrowsUncheckedException() throws DeclaredCheckedException {
+			doThrow(uncheckedException).when(target).doSomething();
+
+			invokeProxy();
+
+			assertThat(throwableSeenByCaller).isSameAs(uncheckedException);
+		}
+	}
+
+	private void invokeProxy() {
+		throwableSeenByCaller = catchThrowable(() -> Objects.requireNonNull(proxy).doSomething());
+	}
+
+	private Answer<?> sneakyThrow(@SuppressWarnings("SameParameterValue") Throwable throwable) {
+		return invocation -> {
+			throw throwable;
+		};
+	}
+
+	static class MyClass implements MyInterface {
+		@Override
+		public void doSomething() throws DeclaredCheckedException {
+			throw declaredCheckedException;
+		}
+	}
+
+	protected interface MyInterface {
+		void doSomething() throws DeclaredCheckedException;
+	}
+
+	protected static class UndeclaredCheckedException extends Exception {
+		@Serial
+		private static final long serialVersionUID = -4199611059122356651L;
+	}
+
+	protected static class DeclaredCheckedException extends Exception {
+		@Serial
+		private static final long serialVersionUID = 8851375818059230518L;
+	}
+
+}

spring-core/src/main/java/org/springframework/cglib/core/ClassLoaderAwareGeneratorStrategy.java

@@ -16,6 +16,10 @@
 
 package org.springframework.cglib.core;
 
+import java.lang.reflect.UndeclaredThrowableException;
+
+import org.springframework.cglib.transform.impl.UndeclaredThrowableStrategy;
+
 /**
  * CGLIB GeneratorStrategy variant which exposes the application ClassLoader
  * as current thread context ClassLoader for the time of class generation.
@@ -25,11 +29,12 @@
  * @author Juergen Hoeller
  * @since 5.2
  */
-public class ClassLoaderAwareGeneratorStrategy extends DefaultGeneratorStrategy {
+public class ClassLoaderAwareGeneratorStrategy extends UndeclaredThrowableStrategy {
 
 	private final ClassLoader classLoader;
 
 	public ClassLoaderAwareGeneratorStrategy(ClassLoader classLoader) {
+		super(UndeclaredThrowableException.class);
 		this.classLoader = classLoader;
 	}
 

spring-core/src/main/java/org/springframework/cglib/transform/impl/UndeclaredThrowableTransformer.java

@@ -27,7 +27,7 @@
 import org.springframework.cglib.core.TypeUtils;
 import org.springframework.cglib.transform.ClassEmitterTransformer;
 
-@SuppressWarnings({"rawtypes", "unchecked"})
+@SuppressWarnings({"rawtypes" })
 public class UndeclaredThrowableTransformer extends ClassEmitterTransformer {
 
     private final Type wrapper;
@@ -55,10 +55,20 @@ public CodeEmitter begin_method(int access, final Signature sig, final Type[] ex
             return e;
         }
         return new CodeEmitter(e) {
-            private Block handler;
-            /* init */ {
-                handler = begin_block();
-            }
+	        private final boolean isConstructor = Constants.CONSTRUCTOR_NAME.equals(sig.getName());
+            private Block handler = begin_block();
+	        private boolean calToSuperWasSeen;
+
+	        @Override
+	        public void visitMethodInsn(int opcode, String owner, String name, String descriptor, boolean isInterface) {
+		        super.visitMethodInsn(opcode, owner, name, descriptor, isInterface);
+		        if (isConstructor && !calToSuperWasSeen && Constants.CONSTRUCTOR_NAME.equals(name)) {
+			        // we start the entry in the exception table after the call to super
+			        handler = begin_block();
+			        calToSuperWasSeen = true;
+		        }
+	        }
+
             @Override
             public void visitMaxs(int maxStack, int maxLocals) {
                 handler.end();