org.jdal.aop.config.SerializableAnnotationBeanPostProcessor.java Source code

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Here is the source code for org.jdal.aop.config.SerializableAnnotationBeanPostProcessor.java

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/*
 * Copyright 2009-2014 Jose Luis Martin.
 *
 * 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.jdal.aop.config;

import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Field;
import java.lang.reflect.Method;
import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.jdal.annotation.AnnotatedElementAccessor;
import org.jdal.annotation.SerializableProxy;
import org.jdal.aop.SerializableProxyUtils;
import org.jdal.aop.SerializableAopProxy;
import org.springframework.aop.framework.AopInfrastructureBean;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.config.DependencyDescriptor;
import org.springframework.beans.factory.config.InstantiationAwareBeanPostProcessorAdapter;
import org.springframework.core.MethodParameter;
import org.springframework.core.ResolvableType;
import org.springframework.core.annotation.AnnotationUtils;

/**
 * BeanPostProcessor that process {@link org.jdal.annotation.SerializableProxy} annotation 
 * for replacing fields or properties with serializable proxies.
 * 
 * @author Jose Luis Martin
 * @since 2.0
 */
public class SerializableAnnotationBeanPostProcessor extends InstantiationAwareBeanPostProcessorAdapter
        implements BeanFactoryAware {

    private static final Log log = LogFactory.getLog(SerializableAnnotationBeanPostProcessor.class);
    private ConfigurableListableBeanFactory beanFactory;

    @Override
    public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException {

        // Check for already serializable, infraestructure or serializable proxy targets.
        if (bean instanceof SerializableAopProxy || bean instanceof AopInfrastructureBean
                || beanName.startsWith(SerializableProxyUtils.TARGET_NAME_PREFIX))
            return bean;

        SerializableProxy ann = AnnotationUtils.findAnnotation(bean.getClass(), SerializableProxy.class);

        if (ann != null) {
            if (log.isDebugEnabled())
                log.debug("Creating serializable proxy for bean [" + beanName + "]");

            boolean proxyTargetClass = !beanFactory.getType(beanName).isInterface() || ann.proxyTargetClass();
            return SerializableProxyUtils.createSerializableProxy(bean, proxyTargetClass, ann.useCache(),
                    beanFactory, beanName);
        }

        return bean;
    }

    /**
     * Create a serializable proxy from given object.
     * @param value object to proxy
     * @return a new serializable proxy
     */
    protected Object getProxy(Object target, boolean proxyTargetClass, boolean useCache,
            DependencyDescriptor descriptor, String beanName) {

        return SerializableProxyUtils.createSerializableProxy(target, proxyTargetClass, useCache, beanFactory,
                descriptor, beanName);
    }

    public BeanFactory getBeanFactory() {
        return this.beanFactory;
    }

    /**
     * {@inheritDoc}
     */
    @Override
    public void setBeanFactory(BeanFactory beanFactory) throws BeansException {
        this.beanFactory = (ConfigurableListableBeanFactory) beanFactory;
    }

    protected DependencyDescriptor getDependencyDescriptor(AnnotatedElement ae) {
        return new DependencyDescriptor((Field) ae, false);
    }

    /**
     * Lookup for {@link SerializableProxy} annotation on fields or methods and 
     * replace value with a Serializable proxy.
     */
    @Override
    public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException {

        List<AnnotatedElement> elements = AnnotatedElementAccessor.findAnnotatedElements(SerializableProxy.class,
                bean.getClass());

        for (AnnotatedElement element : elements) {
            ResolvableType type = getResolvableType(element);
            Object value = AnnotatedElementAccessor.getValue(element, bean);
            if (value != null && !(value instanceof SerializableAopProxy)) {
                SerializableProxy ann = AnnotationUtils.getAnnotation(element, SerializableProxy.class);
                boolean proxyTargetClass = !type.resolve().isInterface() || ann.proxyTargetClass();
                Object proxy = getProxy(value, proxyTargetClass, ann.useCache(), getDependencyDescriptor(element),
                        beanName);
                if (proxy != null)
                    AnnotatedElementAccessor.setValue(element, bean, proxy);
            }
        }

        return bean;
    }

    private ResolvableType getResolvableType(AnnotatedElement element) {
        if (element instanceof Field)
            return ResolvableType.forField((Field) element);
        else if (element instanceof Method)
            return ResolvableType.forMethodParameter(new MethodParameter((Method) element, 0));

        throw new IllegalArgumentException("SerializableProxy annotation should only be applied on types"
                + ", fields or methods but was found in [" + element.toString() + "]");
    }

}