org.alfresco.util.bean.DynamicContextLoader.java Source code

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Here is the source code for org.alfresco.util.bean.DynamicContextLoader.java

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/*
 * Copyright (C) 2005-2012 Alfresco Software Limited.
 *
 * This file is part of Alfresco
 *
 * Alfresco is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Alfresco is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with Alfresco. If not, see <http://www.gnu.org/licenses/>.
 */
package org.alfresco.util.bean;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import java.util.List;

import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.support.GenericApplicationContext;

/**
 * Class which dynamically loads additional Spring contexts defined
 * in its list of {@link ContextLoaderEvaluator}s.
 * 
 * @author rgauss
 */
public class DynamicContextLoader implements ApplicationContextAware {

    private static final Log logger = LogFactory.getLog(DynamicContextLoader.class);

    protected ApplicationContext applicationContext;
    protected List<ContextLoaderEvaluator> contextLoaderEvaluators;

    /* (non-Javadoc)
     * @see org.springframework.context.ApplicationContextAware#setApplicationContext(org.springframework.context.ApplicationContext)
     */
    @Override
    public void setApplicationContext(ApplicationContext applicationContext) {
        this.applicationContext = applicationContext;
    }

    /**
     * Sets the list of ContextLoaderEvaluators to evaluate
     * 
     * @param contextLoaderEvaluators
     */
    public void setContextLoaderEvaluators(List<ContextLoaderEvaluator> contextLoaderEvaluators) {
        this.contextLoaderEvaluators = contextLoaderEvaluators;
    }

    /**
     * Iterates through the list of ContextLoaderEvaluators and loads the additional
     * contexts if appropriate.
     */
    public void init() {
        GenericApplicationContext childContext = new GenericApplicationContext(applicationContext);
        XmlBeanDefinitionReader xmlReader = new XmlBeanDefinitionReader(childContext);
        boolean isContextChanged = false;
        for (ContextLoaderEvaluator contextLoaderEvaluator : contextLoaderEvaluators) {
            if (contextLoaderEvaluator.loadContext()) {
                if (logger.isInfoEnabled()) {
                    logger.info(
                            "Loading dynamic context: " + contextLoaderEvaluator.getContextResource().toString());
                }
                xmlReader.loadBeanDefinitions(contextLoaderEvaluator.getContextResource());
                isContextChanged = true;
            } else {
                if (logger.isInfoEnabled()) {
                    logger.info(
                            "Skipping dynamic context: " + contextLoaderEvaluator.getContextResource().toString());
                }
            }
        }
        if (isContextChanged) {
            childContext.refresh();
        }
    }

}