de.acosix.alfresco.utility.common.spring.ImplementationClassReplacingBeanFactoryPostProcessor.java Source code

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Here is the source code for de.acosix.alfresco.utility.common.spring.ImplementationClassReplacingBeanFactoryPostProcessor.java

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/*
 * Copyright 2016 Acosix GmbH
 *
 * 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 de.acosix.alfresco.utility.common.spring;

import java.util.function.Function;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanNameAware;
import org.springframework.beans.factory.config.BeanDefinition;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;

/**
 * {@link BeanFactoryPostProcessor Bean factory post processor} to alter the implementation class of a bean definition without requiring an
 * override that may conflict with custom Spring configuration.
 *
 * @author Axel Faust, <a href="http://acosix.de">Acosix GmbH</a>
 */
public class ImplementationClassReplacingBeanFactoryPostProcessor
        implements BeanFactoryPostProcessor, BeanNameAware {

    private static final Logger LOGGER = LoggerFactory
            .getLogger(ImplementationClassReplacingBeanFactoryPostProcessor.class);

    protected String beanName;

    protected String originalClassName;

    protected String replacementClassName;

    protected String targetBeanName;

    protected boolean enabled;

    /**
     * {@inheritDoc}
     */
    @Override
    public void setBeanName(final String name) {
        this.beanName = name;
    }

    /**
     * @param originalClassName
     *            the originalClassName to set
     */
    public void setOriginalClassName(final String originalClassName) {
        this.originalClassName = originalClassName;
    }

    /**
     * @param replacementClassName
     *            the replacementClassName to set
     */
    public void setReplacementClassName(final String replacementClassName) {
        this.replacementClassName = replacementClassName;
    }

    /**
     * @param targetBeanName
     *            the targetBeanName to set
     */
    public void setTargetBeanName(final String targetBeanName) {
        this.targetBeanName = targetBeanName;
    }

    /**
     * @param enabled
     *            the enabled to set
     */
    public void setEnabled(final boolean enabled) {
        this.enabled = enabled;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void postProcessBeanFactory(final ConfigurableListableBeanFactory beanFactory) throws BeansException {
        if (this.enabled && this.targetBeanName != null && this.replacementClassName != null) {
            this.applyChange(beanName -> {
                return beanFactory.getBeanDefinition(beanName);
            });
        } else if (!this.enabled) {
            LOGGER.info("[{}] patch will not be applied as it has been marked as inactive", this.beanName);
        } else {
            LOGGER.warn("[{}] patch cannnot be applied as its configuration is incomplete", this.beanName);
        }
    }

    protected void applyChange(final Function<String, BeanDefinition> getBeanDefinition) {
        final BeanDefinition beanDefinition = getBeanDefinition.apply(this.targetBeanName);
        if (beanDefinition != null) {
            if (this.originalClassName == null
                    || this.originalClassName.equals(beanDefinition.getBeanClassName())) {
                LOGGER.debug("[{}] Patching implementation class Spring bean {} to {}", this.beanName,
                        this.targetBeanName, this.replacementClassName);
                beanDefinition.setBeanClassName(this.replacementClassName);
            } else {
                LOGGER.info(
                        "[{}] patch will not be applied - class of bean {} does not match expected implementation {}",
                        this.beanName, this.targetBeanName, this.originalClassName);
            }
        } else {
            LOGGER.info("[{}] patch cannot be applied - no bean with name {} has been defined", this.beanName,
                    this.targetBeanName);
        }
    }

}