BeanDefinitionOverrideException in case of overriding not allowed

Issue: SPR-16982

spring-beans/src/main/java/org/springframework/beans/factory/BeanDefinitionStoreException.java

@@ -84,7 +84,7 @@ public class BeanDefinitionStoreException extends FatalBeanException {
 	/**
 	 * Create a new BeanDefinitionStoreException.
 	 * @param resourceDescription description of the resource that the bean definition came from
-	 * @param beanName the name of the bean requested
+	 * @param beanName the name of the bean
 	 * @param msg the detail message (appended to an introductory message that indicates
 	 * the resource and the name of the bean)
 	 */
@@ -95,21 +95,23 @@ public class BeanDefinitionStoreException extends FatalBeanException {
 	/**
 	 * Create a new BeanDefinitionStoreException.
 	 * @param resourceDescription description of the resource that the bean definition came from
-	 * @param beanName the name of the bean requested
+	 * @param beanName the name of the bean
 	 * @param msg the detail message (appended to an introductory message that indicates
 	 * the resource and the name of the bean)
 	 * @param cause the root cause (may be {@code null})
 	 */
-	public BeanDefinitionStoreException(@Nullable String resourceDescription, String beanName, String msg, @Nullable Throwable cause) {
-		super("Invalid bean definition with name '" + beanName + "' defined in " + resourceDescription + ": " + msg, cause);
+	public BeanDefinitionStoreException(
+			@Nullable String resourceDescription, String beanName, String msg, @Nullable Throwable cause) {
+
+		super("Invalid bean definition with name '" + beanName + "' defined in " + resourceDescription + ": " + msg,
+				cause);
 		this.resourceDescription = resourceDescription;
 		this.beanName = beanName;
 	}
 
 
 	/**
-	 * Return the description of the resource that the bean
-	 * definition came from, if any.
+	 * Return the description of the resource that the bean definition came from, if available.
 	 */
 	@Nullable
 	public String getResourceDescription() {
@@ -117,7 +119,7 @@ public class BeanDefinitionStoreException extends FatalBeanException {
 	}
 
 	/**
-	 * Return the name of the bean requested, if any.
+	 * Return the name of the bean, if available.
 	 */
 	@Nullable
 	public String getBeanName() {

spring-beans/src/main/java/org/springframework/beans/factory/support/BeanDefinitionOverrideException.java

@@ -0,0 +1,91 @@
+/*
+ * Copyright 2002-2018 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
+ *
+ *      http://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.beans.factory.support;
+
+import org.springframework.beans.factory.BeanDefinitionStoreException;
+import org.springframework.beans.factory.config.BeanDefinition;
+import org.springframework.lang.NonNull;
+
+/**
+ * Subclass of {@link BeanDefinitionStoreException} indicating an invalid override
+ * attempt: typically registering a new definition for the same bean name while
+ * {@link DefaultListableBeanFactory#isAllowBeanDefinitionOverriding()} is {@code false}.
+ *
+ * @author Juergen Hoeller
+ * @since 5.1
+ * @see DefaultListableBeanFactory#setAllowBeanDefinitionOverriding
+ * @see DefaultListableBeanFactory#registerBeanDefinition
+ */
+public class BeanDefinitionOverrideException extends BeanDefinitionStoreException {
+
+	private final BeanDefinition beanDefinition;
+
+	private final BeanDefinition existingDefinition;
+
+
+	/**
+	 * Create a new BeanDefinitionOverrideException for the given new and existing definition.
+	 * @param beanName the name of the bean
+	 * @param beanDefinition the newly registered bean definition
+	 * @param existingDefinition the existing bean definition for the same name
+	 */
+	public BeanDefinitionOverrideException(
+			String beanName, BeanDefinition beanDefinition, BeanDefinition existingDefinition) {
+
+		super(beanDefinition.getResourceDescription(), beanName,
+				"Cannot register bean definition [" + beanDefinition + "] for bean '" + beanName +
+				"': There is already [" + existingDefinition + "] bound.");
+		this.beanDefinition = beanDefinition;
+		this.existingDefinition = existingDefinition;
+	}
+
+
+	/**
+	 * Return the description of the resource that the bean definition came from.
+	 */
+	@Override
+	@NonNull
+	public String getResourceDescription() {
+		return String.valueOf(super.getResourceDescription());
+	}
+
+	/**
+	 * Return the name of the bean.
+	 */
+	@Override
+	@NonNull
+	public String getBeanName() {
+		return String.valueOf(super.getBeanName());
+	}
+
+	/**
+	 * Return the newly registered bean definition.
+	 * @see #getBeanName()
+	 */
+	public BeanDefinition getBeanDefinition() {
+		return this.beanDefinition;
+	}
+
+	/**
+	 * Return the existing bean definition for the same name.
+	 * @see #getBeanName()
+	 */
+	public BeanDefinition getExistingDefinition() {
+		return this.existingDefinition;
+	}
+
+}

spring-beans/src/main/java/org/springframework/beans/factory/support/BeanDefinitionRegistry.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2002-2017 the original author or authors.
+ * Copyright 2002-2018 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.
@@ -53,8 +53,9 @@ public interface BeanDefinitionRegistry extends AliasRegistry {
 	 * @param beanName the name of the bean instance to register
 	 * @param beanDefinition definition of the bean instance to register
 	 * @throws BeanDefinitionStoreException if the BeanDefinition is invalid
-	 * or if there is already a BeanDefinition for the specified bean name
-	 * (and we are not allowed to override it)
+	 * @throws BeanDefinitionOverrideException if there is already a BeanDefinition
+	 * for the specified bean name and we are not allowed to override it
+	 * @see GenericBeanDefinition
 	 * @see RootBeanDefinition
 	 * @see ChildBeanDefinition
 	 */

spring-beans/src/main/java/org/springframework/beans/factory/support/DefaultListableBeanFactory.java

@@ -802,34 +802,30 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 			}
 		}
 
-		BeanDefinition oldBeanDefinition;
-
-		oldBeanDefinition = this.beanDefinitionMap.get(beanName);
-		if (oldBeanDefinition != null) {
+		BeanDefinition existingDefinition = this.beanDefinitionMap.get(beanName);
+		if (existingDefinition != null) {
 			if (!isAllowBeanDefinitionOverriding()) {
-				throw new BeanDefinitionStoreException(beanDefinition.getResourceDescription(), beanName,
-						"Cannot register bean definition [" + beanDefinition + "] for bean '" + beanName +
-						"': There is already [" + oldBeanDefinition + "] bound.");
+				throw new BeanDefinitionOverrideException(beanName, beanDefinition, existingDefinition);
 			}
-			else if (oldBeanDefinition.getRole() < beanDefinition.getRole()) {
+			else if (existingDefinition.getRole() < beanDefinition.getRole()) {
 				// e.g. was ROLE_APPLICATION, now overriding with ROLE_SUPPORT or ROLE_INFRASTRUCTURE
 				if (logger.isWarnEnabled()) {
 					logger.warn("Overriding user-defined bean definition for bean '" + beanName +
 							"' with a framework-generated bean definition: replacing [" +
-							oldBeanDefinition + "] with [" + beanDefinition + "]");
+							existingDefinition + "] with [" + beanDefinition + "]");
 				}
 			}
-			else if (!beanDefinition.equals(oldBeanDefinition)) {
+			else if (!beanDefinition.equals(existingDefinition)) {
 				if (logger.isInfoEnabled()) {
 					logger.info("Overriding bean definition for bean '" + beanName +
-							"' with a different definition: replacing [" + oldBeanDefinition +
+							"' with a different definition: replacing [" + existingDefinition +
 							"] with [" + beanDefinition + "]");
 				}
 			}
 			else {
 				if (logger.isDebugEnabled()) {
 					logger.debug("Overriding bean definition for bean '" + beanName +
-							"' with an equivalent definition: replacing [" + oldBeanDefinition +
+							"' with an equivalent definition: replacing [" + existingDefinition +
 							"] with [" + beanDefinition + "]");
 				}
 			}
@@ -860,7 +856,7 @@ public class DefaultListableBeanFactory extends AbstractAutowireCapableBeanFacto
 			this.frozenBeanDefinitionNames = null;
 		}
 
-		if (oldBeanDefinition != null || containsSingleton(beanName)) {
+		if (existingDefinition != null || containsSingleton(beanName)) {
 			resetBeanDefinition(beanName);
 		}
 	}