org.springframework.aop.scope.ScopedProxyUtils.java Source code

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/*
 * Copyright 2002-2017 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.aop.scope;

import org.springframework.aop.framework.autoproxy.AutoProxyUtils;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.BeanDefinitionHolder;
import org.springframework.beans.factory.support.AbstractBeanDefinition;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.support.RootBeanDefinition;
import org.springframework.lang.Nullable;

/**
 * Utility class for creating a scoped proxy.
 * Used by ScopedProxyBeanDefinitionDecorator and ClassPathBeanDefinitionScanner.
 *
 * @author Mark Fisher
 * @author Juergen Hoeller
 * @author Rob Harrop
 * @since 2.5
 */
public abstract class ScopedProxyUtils {

    private static final String TARGET_NAME_PREFIX = "scopedTarget.";

    /**
     * Generate a scoped proxy for the supplied target bean, registering the target
     * bean with an internal name and setting 'targetBeanName' on the scoped proxy.
     * @param definition the original bean definition
     * @param registry the bean definition registry
     * @param proxyTargetClass whether to create a target class proxy
     * @return the scoped proxy definition
     */
    public static BeanDefinitionHolder createScopedProxy(BeanDefinitionHolder definition,
            BeanDefinitionRegistry registry, boolean proxyTargetClass) {

        String originalBeanName = definition.getBeanName();
        BeanDefinition targetDefinition = definition.getBeanDefinition();
        String targetBeanName = getTargetBeanName(originalBeanName);

        // Create a scoped proxy definition for the original bean name,
        // "hiding" the target bean in an internal target definition.
        RootBeanDefinition proxyDefinition = new RootBeanDefinition(ScopedProxyFactoryBean.class);
        proxyDefinition.setDecoratedDefinition(new BeanDefinitionHolder(targetDefinition, targetBeanName));
        proxyDefinition.setOriginatingBeanDefinition(targetDefinition);
        proxyDefinition.setSource(definition.getSource());
        proxyDefinition.setRole(targetDefinition.getRole());

        proxyDefinition.getPropertyValues().add("targetBeanName", targetBeanName);
        if (proxyTargetClass) {
            targetDefinition.setAttribute(AutoProxyUtils.PRESERVE_TARGET_CLASS_ATTRIBUTE, Boolean.TRUE);
            // ScopedProxyFactoryBean's "proxyTargetClass" default is TRUE, so we don't need to set it explicitly here.
        } else {
            proxyDefinition.getPropertyValues().add("proxyTargetClass", Boolean.FALSE);
        }

        // Copy autowire settings from original bean definition.
        proxyDefinition.setAutowireCandidate(targetDefinition.isAutowireCandidate());
        proxyDefinition.setPrimary(targetDefinition.isPrimary());
        if (targetDefinition instanceof AbstractBeanDefinition) {
            proxyDefinition.copyQualifiersFrom((AbstractBeanDefinition) targetDefinition);
        }

        // The target bean should be ignored in favor of the scoped proxy.
        targetDefinition.setAutowireCandidate(false);
        targetDefinition.setPrimary(false);

        // Register the target bean as separate bean in the factory.
        registry.registerBeanDefinition(targetBeanName, targetDefinition);

        // Return the scoped proxy definition as primary bean definition
        // (potentially an inner bean).
        return new BeanDefinitionHolder(proxyDefinition, originalBeanName, definition.getAliases());
    }

    /**
     * Generate the bean name that is used within the scoped proxy to reference the target bean.
     * @param originalBeanName the original name of bean
     * @return the generated bean to be used to reference the target bean
     */
    public static String getTargetBeanName(String originalBeanName) {
        return TARGET_NAME_PREFIX + originalBeanName;
    }

    /**
     * Specify if the {@code beanName} is the name of a bean that references the target
     * bean within a scoped proxy.
     * @since 4.1.4
     */
    public static boolean isScopedTarget(@Nullable String beanName) {
        return (beanName != null && beanName.startsWith(TARGET_NAME_PREFIX));
    }

}