Support scoped @ControllerAdvice beans again

Spring Framework 5.2 introduced support for implementing the Ordered
interface in a @ControllerAdvice bean. This support requires that
@ControllerAdvice beans be eagerly resolved from the BeanFactory in
order to invoke the getOrder() method defined in the Ordered interface.
Unfortunately doing so resulted in a regression in that an attempt to
eagerly resolve a scoped @ControllerAdvice bean throws a
BeanCreationException due to the lack of an active scope (e.g., request
or session scope).

This commit fixes this regression by avoiding eager resolution of scoped
@ControllerAdvice beans. As a direct consequence, the Ordered interface
is not supported for scoped @ControllerAdvice beans.

Closes gh-23985

spring-web/src/main/java/org/springframework/web/bind/annotation/ControllerAdvice.java

@@ -42,10 +42,12 @@ import org.springframework.stereotype.Component;
  * Note, however, that {@code @ControllerAdvice} beans that implement
  * {@link org.springframework.core.PriorityOrdered PriorityOrdered} are <em>not</em>
  * given priority over {@code @ControllerAdvice} beans that implement {@code Ordered}.
- * For handling exceptions, an {@code @ExceptionHandler} will be picked on the
- * first advice with a matching exception handler method. For model attributes
- * and {@code InitBinder} initialization, {@code @ModelAttribute} and
- * {@code @InitBinder} methods will also follow {@code @ControllerAdvice} order.
+ * In addition, {@code Ordered} is not honored for scoped {@code @ControllerAdvice}
+ * beans &mdash; for example if such a bean has been configured as a request-scoped
+ * or session-scoped bean.  For handling exceptions, an {@code @ExceptionHandler}
+ * will be picked on the first advice with a matching exception handler method. For
+ * model attributes and data binding initialization, {@code @ModelAttribute} and
+ * {@code @InitBinder} methods will follow {@code @ControllerAdvice} order.
  *
  * <p>Note: For {@code @ExceptionHandler} methods, a root exception match will be
  * preferred to just matching a cause of the current exception, among the handler

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

@@ -19,6 +19,7 @@ package org.springframework.web.method;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.springframework.aop.scope.ScopedProxyUtils;
 import org.springframework.beans.factory.BeanFactory;
 import org.springframework.beans.factory.BeanFactoryUtils;
 import org.springframework.context.ApplicationContext;
@@ -124,19 +125,42 @@ public class ControllerAdviceBean implements Ordered {
 	/**
 	 * Get the order value for the contained bean.
 	 * <p>As of Spring Framework 5.2, the order value is lazily retrieved using
-	 * the following algorithm and cached.
+	 * the following algorithm and cached. Note, however, that a
+	 * {@link ControllerAdvice @ControllerAdvice} bean that is configured as a
+	 * scoped bean &mdash; for example, as a request-scoped or session-scoped
+	 * bean &mdash; will not be eagerly resolved. Consequently, {@link Ordered} is
+	 * not honored for scoped {@code @ControllerAdvice} beans.
 	 * <ul>
 	 * <li>If the {@linkplain #resolveBean resolved bean} implements {@link Ordered},
 	 * use the value returned by {@link Ordered#getOrder()}.</li>
-	 * <li>Otherwise use the value returned by {@link OrderUtils#getOrder(Class, int)}
-	 * with {@link Ordered#LOWEST_PRECEDENCE} used as the default order value.</li>
+	 * <li>If the {@linkplain #getBeanType() bean type} is known, use the value returned
+	 * by {@link OrderUtils#getOrder(Class, int)} with {@link Ordered#LOWEST_PRECEDENCE}
+	 * used as the default order value.</li>
+	 * <li>Otherwise use {@link Ordered#LOWEST_PRECEDENCE} as the default, fallback
+	 * order value.</li>
 	 * </ul>
 	 * @see #resolveBean()
 	 */
 	@Override
 	public int getOrder() {
 		if (this.order == null) {
-			Object resolvedBean = resolveBean();
+			Object resolvedBean = null;
+			if (this.beanOrName instanceof String) {
+				String beanName = (String) this.beanOrName;
+				String targetBeanName = ScopedProxyUtils.getTargetBeanName(beanName);
+				boolean isScopedProxy = this.beanFactory.containsBean(targetBeanName);
+				// Avoid eager @ControllerAdvice bean resolution for scoped proxies,
+				// since attempting to do so during context initialization would result
+				// in an exception due to the current absence of the scope. For example,
+				// an HTTP request or session scope is not active during initialization.
+				if (!isScopedProxy && !ScopedProxyUtils.isScopedTarget(beanName)) {
+					resolvedBean = resolveBean();
+				}
+			}
+			else {
+				resolvedBean = resolveBean();
+			}
+
 			if (resolvedBean instanceof Ordered) {
 				this.order = ((Ordered) resolvedBean).getOrder();
 			}

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

@@ -0,0 +1,91 @@
+/*
+ * Copyright 2002-2019 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.web.servlet.mvc.method.annotation;
+
+import java.util.List;
+
+import org.junit.jupiter.api.Test;
+
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+import org.springframework.core.Ordered;
+import org.springframework.core.annotation.Order;
+import org.springframework.mock.web.test.MockServletContext;
+import org.springframework.web.bind.annotation.ControllerAdvice;
+import org.springframework.web.context.annotation.RequestScope;
+import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
+import org.springframework.web.method.ControllerAdviceBean;
+import org.springframework.web.servlet.config.annotation.EnableWebMvc;
+
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.api.Assertions.assertThatCode;
+
+/**
+ * Integration tests for request-scoped {@link ControllerAdvice @ControllerAdvice} beans.
+ *
+ * @author Sam Brannen
+ * @since 5.2.2
+ */
+class RequestScopedControllerAdviceIntegrationTests {
+
+	@Test // gh-23985
+	@SuppressWarnings({ "rawtypes", "unchecked" })
+	void loadContextWithRequestScopedControllerAdvice() {
+		AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
+		context.setServletContext(new MockServletContext());
+		context.register(Config.class);
+
+		assertThatCode(context::refresh).doesNotThrowAnyException();
+
+		// Until gh-24017 is fixed, we expect the RequestScopedControllerAdvice to show up twice.
+		Class[] expectedTypes = { RequestScopedControllerAdvice.class, RequestScopedControllerAdvice.class };
+
+		List<ControllerAdviceBean> adviceBeans = ControllerAdviceBean.findAnnotatedBeans(context);
+		assertThat(adviceBeans)//
+				.extracting(ControllerAdviceBean::getBeanType)//
+				.containsExactly(expectedTypes);
+
+		assertThat(adviceBeans)//
+				.extracting(ControllerAdviceBean::getOrder)//
+				.containsExactly(42, 42);
+
+		context.close();
+	}
+
+
+	@Configuration
+	@EnableWebMvc
+	static class Config {
+
+		@Bean
+		@RequestScope
+		RequestScopedControllerAdvice requestScopedControllerAdvice() {
+			return new RequestScopedControllerAdvice();
+		}
+	}
+
+	@ControllerAdvice
+	@Order(42)
+	static class RequestScopedControllerAdvice implements Ordered {
+
+		@Override
+		public int getOrder() {
+			return 99;
+		}
+	}
+
+}