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/* * 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 * * 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.beans.factory.support; import org.springframework.beans.factory.BeanDefinitionStoreException; import org.springframework.beans.factory.BeanFactoryUtils; import org.springframework.beans.factory.config.BeanDefinition; import org.springframework.beans.factory.config.BeanDefinitionHolder; import org.springframework.lang.Nullable; import org.springframework.util.ClassUtils; import org.springframework.util.ObjectUtils; import org.springframework.util.StringUtils; /** * Utility methods that are useful for bean definition reader implementations. * Mainly intended for internal use. * * @author Juergen Hoeller * @author Rob Harrop * @since 1.1 * @see PropertiesBeanDefinitionReader * @see org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader */ public abstract class BeanDefinitionReaderUtils { /** * Separator for generated bean names. If a class name or parent name is not * unique, "#1", "#2" etc will be appended, until the name becomes unique. */ public static final String GENERATED_BEAN_NAME_SEPARATOR = BeanFactoryUtils.GENERATED_BEAN_NAME_SEPARATOR; /** * Create a new GenericBeanDefinition for the given parent name and class name, * eagerly loading the bean class if a ClassLoader has been specified. * @param parentName the name of the parent bean, if any * @param className the name of the bean class, if any * @param classLoader the ClassLoader to use for loading bean classes * (can be {@code null} to just register bean classes by name) * @return the bean definition * @throws ClassNotFoundException if the bean class could not be loaded */ public static AbstractBeanDefinition createBeanDefinition(@Nullable String parentName, @Nullable String className, @Nullable ClassLoader classLoader) throws ClassNotFoundException { GenericBeanDefinition bd = new GenericBeanDefinition(); bd.setParentName(parentName); if (className != null) { if (classLoader != null) { bd.setBeanClass(ClassUtils.forName(className, classLoader)); } else { bd.setBeanClassName(className); } } return bd; } /** * Generate a bean name for the given top-level bean definition, * unique within the given bean factory. * @param beanDefinition the bean definition to generate a bean name for * @param registry the bean factory that the definition is going to be * registered with (to check for existing bean names) * @return the generated bean name * @throws BeanDefinitionStoreException if no unique name can be generated * for the given bean definition * @see #generateBeanName(BeanDefinition, BeanDefinitionRegistry, boolean) */ public static String generateBeanName(BeanDefinition beanDefinition, BeanDefinitionRegistry registry) throws BeanDefinitionStoreException { return generateBeanName(beanDefinition, registry, false); } /** * Generate a bean name for the given bean definition, unique within the * given bean factory. * @param definition the bean definition to generate a bean name for * @param registry the bean factory that the definition is going to be * registered with (to check for existing bean names) * @param isInnerBean whether the given bean definition will be registered * as inner bean or as top-level bean (allowing for special name generation * for inner beans versus top-level beans) * @return the generated bean name * @throws BeanDefinitionStoreException if no unique name can be generated * for the given bean definition */ public static String generateBeanName(BeanDefinition definition, BeanDefinitionRegistry registry, boolean isInnerBean) throws BeanDefinitionStoreException { String generatedBeanName = definition.getBeanClassName(); if (generatedBeanName == null) { if (definition.getParentName() != null) { generatedBeanName = definition.getParentName() + "$child"; } else if (definition.getFactoryBeanName() != null) { generatedBeanName = definition.getFactoryBeanName() + "$created"; } } if (!StringUtils.hasText(generatedBeanName)) { throw new BeanDefinitionStoreException("Unnamed bean definition specifies neither " + "'class' nor 'parent' nor 'factory-bean' - can't generate bean name"); } String id = generatedBeanName; if (isInnerBean) { // Inner bean: generate identity hashcode suffix. id = generatedBeanName + GENERATED_BEAN_NAME_SEPARATOR + ObjectUtils.getIdentityHexString(definition); } else { // Top-level bean: use plain class name with unique suffix if necessary. return uniqueBeanName(generatedBeanName, registry); } return id; } /** * Turn the given bean name into a unique bean name for the given bean factory, * appending a unique counter as suffix if necessary. * @param beanName the original bean name * @param registry the bean factory that the definition is going to be * registered with (to check for existing bean names) * @return the unique bean name to use * @since 5.1 */ public static String uniqueBeanName(String beanName, BeanDefinitionRegistry registry) { String id = beanName; int counter = -1; // Increase counter until the id is unique. while (counter == -1 || registry.containsBeanDefinition(id)) { counter++; id = beanName + GENERATED_BEAN_NAME_SEPARATOR + counter; } return id; } /** * Register the given bean definition with the given bean factory. * @param definitionHolder the bean definition including name and aliases * @param registry the bean factory to register with * @throws BeanDefinitionStoreException if registration failed */ public static void registerBeanDefinition(BeanDefinitionHolder definitionHolder, BeanDefinitionRegistry registry) throws BeanDefinitionStoreException { // Register bean definition under primary name. String beanName = definitionHolder.getBeanName(); registry.registerBeanDefinition(beanName, definitionHolder.getBeanDefinition()); // Register aliases for bean name, if any. String[] aliases = definitionHolder.getAliases(); if (aliases != null) { for (String alias : aliases) { registry.registerAlias(beanName, alias); } } } /** * Register the given bean definition with a generated name, * unique within the given bean factory. * @param definition the bean definition to generate a bean name for * @param registry the bean factory to register with * @return the generated bean name * @throws BeanDefinitionStoreException if no unique name can be generated * for the given bean definition or the definition cannot be registered */ public static String registerWithGeneratedName(AbstractBeanDefinition definition, BeanDefinitionRegistry registry) throws BeanDefinitionStoreException { String generatedName = generateBeanName(definition, registry, false); registry.registerBeanDefinition(generatedName, definition); return generatedName; } }