Avoid early initialization of empty interceptor names

Closes gh-12238

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

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -421,11 +421,7 @@ public class ProxyFactoryBean extends ProxyCreatorSupport
 	 * are unaffected by such changes.
 	 */
 	private synchronized void initializeAdvisorChain() throws AopConfigException, BeansException {
-		if (this.advisorChainInitialized) {
-			return;
-		}
-
-		if (!ObjectUtils.isEmpty(this.interceptorNames)) {
+		if (!this.advisorChainInitialized && !ObjectUtils.isEmpty(this.interceptorNames)) {
 			if (this.beanFactory == null) {
 				throw new IllegalStateException("No BeanFactory available anymore (probably due to serialization) " +
 						"- cannot resolve interceptor names " + Arrays.asList(this.interceptorNames));
@@ -464,9 +460,9 @@ public class ProxyFactoryBean extends ProxyCreatorSupport
 					addAdvisorOnChainCreation(advice);
 				}
 			}
-		}
 
-		this.advisorChainInitialized = true;
+			this.advisorChainInitialized = true;
+		}
 	}
 
 

spring-context/src/test/java/org/springframework/aop/framework/ProxyFactoryBeanTests.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2020 the original author or authors.
+ * Copyright 2002-2021 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.
@@ -65,10 +65,10 @@ import static org.assertj.core.api.Assertions.assertThatExceptionOfType;
 import static org.assertj.core.api.Assertions.assertThatIOException;
 
 /**
- * @since 13.03.2003
  * @author Rod Johnson
  * @author Juergen Hoeller
  * @author Chris Beams
+ * @since 13.03.2003
  */
 public class ProxyFactoryBeanTests {
 
@@ -633,20 +633,50 @@ public class ProxyFactoryBeanTests {
 		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
 		new XmlBeanDefinitionReader(bf).loadBeanDefinitions(new ClassPathResource(FROZEN_CONTEXT, CLASS));
 
-		Advised advised = (Advised)bf.getBean("frozen");
+		Advised advised = (Advised) bf.getBean("frozen");
 		assertThat(advised.isFrozen()).as("The proxy should be frozen").isTrue();
 	}
 
 	@Test
-	public void testDetectsInterfaces() throws Exception {
+	public void testDetectsInterfaces() {
 		ProxyFactoryBean fb = new ProxyFactoryBean();
 		fb.setTarget(new TestBean());
 		fb.addAdvice(new DebugInterceptor());
 		fb.setBeanFactory(new DefaultListableBeanFactory());
+
 		ITestBean proxy = (ITestBean) fb.getObject();
 		assertThat(AopUtils.isJdkDynamicProxy(proxy)).isTrue();
 	}
 
+	@Test
+	public void testWithInterceptorNames() {
+		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
+		bf.registerSingleton("debug", new DebugInterceptor());
+
+		ProxyFactoryBean fb = new ProxyFactoryBean();
+		fb.setTarget(new TestBean());
+		fb.setInterceptorNames("debug");
+		fb.setBeanFactory(bf);
+
+		Advised proxy = (Advised) fb.getObject();
+		assertThat(proxy.getAdvisorCount()).isEqualTo(1);
+	}
+
+	@Test
+	public void testWithLateInterceptorNames() {
+		DefaultListableBeanFactory bf = new DefaultListableBeanFactory();
+		bf.registerSingleton("debug", new DebugInterceptor());
+
+		ProxyFactoryBean fb = new ProxyFactoryBean();
+		fb.setTarget(new TestBean());
+		fb.setBeanFactory(bf);
+		fb.getObject();
+
+		fb.setInterceptorNames("debug");
+		Advised proxy = (Advised) fb.getObject();
+		assertThat(proxy.getAdvisorCount()).isEqualTo(1);
+	}
+
 
 	/**
 	 * Fires only on void methods. Saves list of methods intercepted.