org.sakaiproject.util.SakaiApplicationContext.java Source code

Introduction

Here is the source code for org.sakaiproject.util.SakaiApplicationContext.java

Source

/**********************************************************************************
*
* $Id$
*
***********************************************************************************
*
* Copyright (c) 2007 The Regents of the University of California
*
* Licensed under the Educational Community License, Version 1.0 (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.opensource.org/licenses/ecl1.php
*
* 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.sakaiproject.util;

import java.io.IOException;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanFactoryPostProcessor;
import org.springframework.beans.factory.config.ConfigurableListableBeanFactory;
import org.springframework.beans.factory.support.BeanDefinitionRegistry;
import org.springframework.beans.factory.xml.ResourceEntityResolver;
import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
import org.springframework.context.ApplicationContextException;
import org.springframework.context.support.GenericApplicationContext;

/**
 * Hook some Sakai-specific operations into the normal ApplicationContext
 * refresh cycle: read component manager configuration files, give creators of
 * PostProcessor objects (e.g., SakaiProperties) a chance to do their work,
 * and load a few central components before the rest.
 */
public class SakaiApplicationContext extends GenericApplicationContext {
    private String[] initialSingletonNames;
    private String[] configLocations;

    public SakaiApplicationContext() {
        super(new NoisierDefaultListableBeanFactory());
    }

    /**
     * Load component manager configurations. A more normal hook for this is
     * the "refreshBeanFactory" method, but it's declared final by GenericApplicationContext.
     */
    protected void prepareBeanFactory(ConfigurableListableBeanFactory beanFactory) {
        super.prepareBeanFactory(beanFactory);
        try {
            loadBeanDefinitions(beanFactory);
        } catch (IOException e) {
            throw new ApplicationContextException(
                    "I/O error parsing XML document for application context [" + getDisplayName() + "]", e);
        }
    }

    protected void loadBeanDefinitions(ConfigurableListableBeanFactory beanFactory) throws IOException {
        // Create a new XmlBeanDefinitionReader for the given BeanFactory.
        XmlBeanDefinitionReader beanDefinitionReader = new XmlBeanDefinitionReader(
                (BeanDefinitionRegistry) beanFactory);
        beanDefinitionReader.setBeanClassLoader(Thread.currentThread().getContextClassLoader());
        beanDefinitionReader.setResourceLoader(this);
        beanDefinitionReader.setEntityResolver(new ResourceEntityResolver(this));

        if (configLocations != null) {
            beanDefinitionReader.loadBeanDefinitions(configLocations);
        }
    }

    /**
     * Before post-processing, load beans which have declared that they want to add post-processors
     * dynamically.
     */
    protected void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) {
        invokePostProcessorCreators(beanFactory);
        super.postProcessBeanFactory(beanFactory);
    }

    /**
     * Load initial beans before going through the default logic.
     */
    protected void onRefresh() throws BeansException {
        if (initialSingletonNames != null) {
            for (int i = 0; i < initialSingletonNames.length; i++) {
                getBean(initialSingletonNames[i]);
            }
        }
        super.onRefresh();
    }

    /**
     * Add bean-created post processors.
     * @param beanFactory
     */
    public void invokePostProcessorCreators(ConfigurableListableBeanFactory beanFactory) {
        String[] postProcessorCreatorNames = beanFactory.getBeanNamesForType(BeanFactoryPostProcessorCreator.class,
                false, false);
        for (int i = 0; i < postProcessorCreatorNames.length; i++) {
            BeanFactoryPostProcessorCreator postProcessorCreator = (BeanFactoryPostProcessorCreator) beanFactory
                    .getBean(postProcessorCreatorNames[i]);
            for (BeanFactoryPostProcessor beanFactoryPostProcessor : postProcessorCreator
                    .getBeanFactoryPostProcessors()) {
                addBeanFactoryPostProcessor(beanFactoryPostProcessor);
            }
        }
    }

    /**
     * @param initialSingletonNames initial configuration beans to load, behaving
     * as universal "dependsOn" targets
     */
    public void setInitialSingletonNames(String[] initialSingletonNames) {
        this.initialSingletonNames = initialSingletonNames;
    }

    /**
     * @param configLocations file paths of XML bean definition files to load before refresh
     */
    public void setConfigLocations(String[] configLocations) {
        this.configLocations = configLocations;
    }
}