org.sipfoundry.sipxconfig.common.SpringHibernateInstantiator.java Source code

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Here is the source code for org.sipfoundry.sipxconfig.common.SpringHibernateInstantiator.java

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/*
 *
 *
 * Copyright (C) 2007 Pingtel Corp., certain elements licensed under a Contributor Agreement.
 * Contributors retain copyright to elements licensed under a Contributor Agreement.
 * Licensed to the User under the LGPL license.
 *
 * $
 */
package org.sipfoundry.sipxconfig.common;

import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;

import org.apache.commons.collections.Transformer;
import org.apache.commons.collections.map.LazyMap;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.EmptyInterceptor;
import org.hibernate.EntityMode;
import org.hibernate.SessionFactory;
import org.hibernate.metadata.ClassMetadata;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.BeanFactoryAware;
import org.springframework.beans.factory.ListableBeanFactory;

/**
 * Enables Spring to create the hibernate object. Use to allow Spring to manage object
 * dependencies with hibernate.
 *
 * Note: it inherits from IndexingInterceptor: only one interceptor can be registered with
 * hibernate session.
 */
public class SpringHibernateInstantiator extends EmptyInterceptor implements BeanFactoryAware {
    private static final Log LOG = LogFactory.getLog(SpringHibernateInstantiator.class);
    private ListableBeanFactory m_beanFactory;
    private SessionFactory m_sessionFactory;
    private Map m_beanNamesCache;

    /**
     * This implementation only supports BeanWithId objects with integer ids
     */
    public Object instantiate(String entityName, EntityMode entityMode, Serializable id) {
        ClassMetadata classMetadata = m_sessionFactory.getClassMetadata(entityName);
        Class clazz = classMetadata.getMappedClass(entityMode);
        return instantiate(clazz, id);
    }

    Object instantiate(Class clazz, Serializable id) {
        String beanName = (String) m_beanNamesCache.get(clazz);
        if (beanName == null) {
            return null;
        }

        BeanWithId bean = (BeanWithId) m_beanFactory.getBean(beanName, BeanWithId.class);
        bean.setId((Integer) id);

        String decoratorName = clazz.getSimpleName().toLowerCase() + "Decorator";
        if (m_beanFactory.containsBean(decoratorName)) {
            EntityDecorator decorator = (EntityDecorator) m_beanFactory.getBean(decoratorName);
            decorator.decorateEntity(bean, id);
        }
        return bean;
    }

    private static class ClassToBeanName implements Transformer {
        private ListableBeanFactory m_beanFactory;

        ClassToBeanName(ListableBeanFactory beanFactory) {
            m_beanFactory = beanFactory;
        }

        public Object transform(Object input) {
            Class clazz = (Class) input;
            String[] beanDefinitionNames = m_beanFactory.getBeanNamesForType(clazz);
            LOG.debug(beanDefinitionNames.length + " beans registered for class: " + clazz.getName());
            for (int i = 0; i < beanDefinitionNames.length; i++) {
                Object bean = m_beanFactory.getBean(beanDefinitionNames[i]);

                if (clazz == bean.getClass()) {
                    // only return the bean name if class matches exactly - no
                    // subclasses
                    return beanDefinitionNames[i];
                }
            }
            return null;
        }
    }

    /**
     * This can only be used withy listeable bean factory
     */
    public void setBeanFactory(BeanFactory beanFactory) {
        m_beanFactory = (ListableBeanFactory) beanFactory;
        Transformer transformer = new ClassToBeanName(m_beanFactory);
        m_beanNamesCache = LazyMap.decorate(new HashMap(), transformer);
    }

    public BeanFactory getBeanFactory() {
        return m_beanFactory;
    }

    public void setSessionFactory(SessionFactory sessionFactory) {
        m_sessionFactory = sessionFactory;
    }

}