org.impalaframework.module.beanset.ImportingBeanDefinitionDocumentReader.java Source code

Introduction

Here is the source code for org.impalaframework.module.beanset.ImportingBeanDefinitionDocumentReader.java

Source

/*
 * Copyright 2007-2010 the original author or authors.
 * 
 * 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.impalaframework.module.beanset;

import java.util.HashSet;
import java.util.Properties;
import java.util.Set;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.FatalBeanException;
import org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader;
import org.springframework.beans.factory.xml.XmlReaderContext;
import org.springframework.util.SystemPropertyUtils;
import org.w3c.dom.Document;
import org.w3c.dom.Element;

/**
 * Overrides <code>DefaultBeanDefinitionDocumentReader</code> to implement
 * smart importing using the <code>beanset:</code> prefix
 * @author Phil Zoio
 */
public class ImportingBeanDefinitionDocumentReader extends DefaultBeanDefinitionDocumentReader {

    static String BEANSET_PREFIX = "beanset:";

    private Set<String> importedResources;

    private Set<String> namedResources;

    Properties beanSetMappings;

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

    public ImportingBeanDefinitionDocumentReader(Properties beanSetMappings) {
        super();
        this.importedResources = new HashSet<String>();
        this.namedResources = new HashSet<String>();
        this.beanSetMappings = beanSetMappings;
    }

    @Override
    public void registerBeanDefinitions(Document doc, XmlReaderContext readerContext) {
        String filename = readerContext.getResource().getFilename();
        if (logger.isInfoEnabled())
            logger.info("Registering definitions for " + filename);

        if (!importedResources.contains(filename))
            namedResources.add(filename);
        doRegisterBeanDefinitions(filename, doc, readerContext);
    }

    @Override
    protected void importBeanDefinitionResource(Element element) {
        String location = element.getAttribute(RESOURCE_ATTRIBUTE);
        location = SystemPropertyUtils.resolvePlaceholders(location);

        if (logger.isDebugEnabled())
            logger.debug("Handling import definition location ... " + location);

        String beanSetName = null;

        if (location.startsWith(BEANSET_PREFIX)) {
            beanSetName = location.substring(BEANSET_PREFIX.length());

            if (logger.isDebugEnabled())
                logger.debug("Beanset key ... " + beanSetName);

            String beanSetLocation = beanSetMappings.getProperty(beanSetName);

            if (beanSetLocation == null) {
                throw new FatalBeanException("Unable to find methodName for beanset key " + beanSetName);
            }
            location = beanSetLocation;
            element.setAttribute(RESOURCE_ATTRIBUTE, beanSetLocation);
        }

        boolean ignore = true;

        boolean alreadyImported = importedResources.contains(location);
        boolean alreadyLoaded = false;

        if (alreadyImported)
            notifyAlreadyImported(location);

        if (!alreadyImported)
            alreadyLoaded = namedResources.contains(location);

        if (alreadyLoaded)
            notifyAlreadyLoaded(location);

        ignore = alreadyImported || alreadyLoaded;

        if (!ignore) {
            if (logger.isInfoEnabled())
                logger.info("Importing resource " + location);

            importedResources.add(location);
            doImportBeanDefinitionResource(location, beanSetName, element);
        }
    }

    void notifyAlreadyLoaded(String location) {
        if (logger.isInfoEnabled()) {
            logger.info("Ignoring resource loaded explicitly: " + location);
        }
    }

    void notifyAlreadyImported(String location) {
        if (logger.isInfoEnabled()) {
            logger.info("Ignoring resource already imported: " + location);
        }
    }

    protected void doImportBeanDefinitionResource(String filename, String beansetLocation, Element ele) {
        super.importBeanDefinitionResource(ele);
    }

    protected void doRegisterBeanDefinitions(String fileName, Document doc, XmlReaderContext readerContext) {
        super.registerBeanDefinitions(doc, readerContext);
    }
}