Polish contribution

See spring-projectsgh-24157

spring-web/src/main/java/org/springframework/web/method/ControllerAdviceBean.java

@@ -54,7 +54,8 @@ public class ControllerAdviceBean implements Ordered {
 	 */
 	private final Object beanOrName;
 
-	private final boolean isSingletonBean;
+	private final boolean isSingleton;
+
 	/**
 	 * Reference to the resolved bean instance, potentially lazily retrieved
 	 * via the {@code BeanFactory}.
@@ -81,11 +82,11 @@ public class ControllerAdviceBean implements Ordered {
 	public ControllerAdviceBean(Object bean) {
 		Assert.notNull(bean, "Bean must not be null");
 		this.beanOrName = bean;
+		this.isSingleton = true;
 		this.resolvedBean = bean;
 		this.beanType = ClassUtils.getUserClass(bean.getClass());
 		this.beanTypePredicate = createBeanTypePredicate(this.beanType);
 		this.beanFactory = null;
-		this.isSingletonBean = true;
 	}
 
 	/**
@@ -117,7 +118,7 @@ public ControllerAdviceBean(String beanName, BeanFactory beanFactory, @Nullable
 				"] does not contain specified controller advice bean '" + beanName + "'");
 
 		this.beanOrName = beanName;
-		this.isSingletonBean = beanFactory.isSingleton(beanName);
+		this.isSingleton = beanFactory.isSingleton(beanName);
 		this.beanType = getBeanType(beanName, beanFactory);
 		this.beanTypePredicate = (controllerAdvice != null ? createBeanTypePredicate(controllerAdvice) :
 				createBeanTypePredicate(this.beanType));
@@ -191,13 +192,19 @@ public Class<?> getBeanType() {
 	 * Get the bean instance for this {@code ControllerAdviceBean}, if necessary
 	 * resolving the bean name through the {@link BeanFactory}.
 	 * <p>As of Spring Framework 5.2, once the bean instance has been resolved it
-	 * will be cached, thereby avoiding repeated lookups in the {@code BeanFactory}.
+	 * will be cached if it is a singleton, thereby avoiding repeated lookups in
+	 * the {@code BeanFactory}.
 	 */
 	public Object resolveBean() {
-		if (!this.isSingletonBean || this.resolvedBean == null) {
+		if (this.resolvedBean == null) {
 			// this.beanOrName must be a String representing the bean name if
 			// this.resolvedBean is null.
-			this.resolvedBean = obtainBeanFactory().getBean((String) this.beanOrName);
+			Object resolvedBean = obtainBeanFactory().getBean((String) this.beanOrName);
+			// Don't cache non-singletons (e.g., prototypes).
+			if (!this.isSingleton) {
+				return resolvedBean;
+			}
+			this.resolvedBean = resolvedBean;
 		}
 		return this.resolvedBean;
 	}

spring-webmvc/src/test/java/org/springframework/web/servlet/mvc/method/annotation/RequestMappingHandlerAdapterTests.java

@@ -207,19 +207,18 @@ public void modelAttributeAdvice() throws Exception {
 	}
 
 	@Test
-	public void prototypePageControllerAdvice() throws Exception {
+	public void prototypeControllerAdvice() throws Exception {
 		this.webAppContext.registerPrototype("maa", ModelAttributeAdvice.class);
 		this.webAppContext.refresh();
 
 		HandlerMethod handlerMethod = handlerMethod(new SimpleController(), "handle");
 		this.handlerAdapter.afterPropertiesSet();
-		ModelAndView mav1 = this.handlerAdapter.handle(this.request, this.response, handlerMethod);
-		ModelAndView mav2 = this.handlerAdapter.handle(this.request, this.response, handlerMethod);
+		Map<String, Object> model1 = this.handlerAdapter.handle(this.request, this.response, handlerMethod).getModel();
+		Map<String, Object> model2 = this.handlerAdapter.handle(this.request, this.response, handlerMethod).getModel();
 
-		assertThat(mav1.getModel().get("modelAttributeAdviceInstance")).isNotEqualTo(mav2.getModel().get("modelAttributeAdviceInstance"));
+		assertThat(model1.get("instance")).isNotSameAs(model2.get("instance"));
 	}
 
-
 	@Test
 	public void modelAttributeAdviceInParentContext() throws Exception {
 		StaticWebApplicationContext parent = new StaticWebApplicationContext();
@@ -336,7 +335,7 @@ private static class ModelAttributeAdvice {
 		public void addAttributes(Model model) {
 			model.addAttribute("attr1", "gAttr1");
 			model.addAttribute("attr2", "gAttr2");
-			model.addAttribute("modelAttributeAdviceInstance", this);
+			model.addAttribute("instance", this);
 		}
 	}