MySports App/src/example/mysports/persistence/JaxbContextFactory.java

/*******************************************************************************
 * Copyright (c) 2010-2012 Oracle. All rights reserved.
 * This program and the accompanying materials are made available under the 
 * terms of the Eclipse Public License v1.0 and Eclipse Distribution License v. 1.0 
 * which accompanies this distribution. 
 * The Eclipse Public License is available at http://www.eclipse.org/legal/epl-v10.html
 * and the Eclipse Distribution License is available at 
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * Contributors:
 *  dclarke - EclipseLink 2.4 - MySports Demo Bug 344608
 ******************************************************************************/
package example.mysports.persistence;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.persistence.EntityManagerFactory;
import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;

import org.eclipse.persistence.config.SessionCustomizer;
import org.eclipse.persistence.jaxb.JAXBContextFactory;
import org.eclipse.persistence.sessions.Session;

import example.mysports.MySportsConfig;
import example.mysports.model.Divisions;

/**
 * Create an EclipseLink {@link JAXBContext} which is built from the
 * {@value #MAPPING_FILE} combined with the virtual attribute extended mappings
 * returned from the call to the Admin server.
 * 
 * @author dclarke
 * @since EclipseLink 2.4
 */
public class JaxbContextFactory implements SessionCustomizer {

    /**
     * Property name for caching the {@link JAXBContext} for the league within
     * its {@link EntityManagerFactory}
     */
    private static final String JAXB_CONTEXT = org.eclipse.persistence.jaxb.JAXBContext.class.getName();

    /**
     * EclipseLink MOXy mapping file to use when creating the context
     */
    private static final String MAPPING_FILE = "META-INF/eclipselink-oxm.xml";

    @Override
    public void customize(Session session) throws Exception {
        getJAXBContext(session.getProperties());
    }

    /**
     * Create an EclipseLink {@link JAXBContext} which is built from the
     * {@value #MAPPING_FILE} combined with the virtual attribute extended
     * mappings returned from the call to the Admin server.
     * 
     * @param properties
     */
    @SuppressWarnings({ "rawtypes", "unchecked" })
    public static JAXBContext getJAXBContext(Map properties) {
        JAXBContext context = (JAXBContext) properties.get(JAXB_CONTEXT);
        MySportsConfig config = MySportsConfig.get(properties);
        String leagueId = (String) properties.get(MySportsConfig.LEAGUE_CONTEXT);

        if (context == null && leagueId != null) {
            Map<String, Object> props = new HashMap<String, Object>();

            List<String> xmlBindings = new ArrayList<String>();
            xmlBindings.add(MAPPING_FILE);

            String url = config.getAdminConnector().getOxmURL(leagueId);
            if (url != null) {
                xmlBindings.add(url);
            }
            props.put(JAXBContextFactory.ECLIPSELINK_OXM_XML_KEY, xmlBindings);

            try {
                context = JAXBContextFactory.createContext(new Class[] { Divisions.class }, props);
            } catch (JAXBException e) {
                throw new RuntimeException("JAXB Failure to create context. League: " + leagueId, e);
            }

            // Cache the JAXB context in the shared session's properties
            properties.put(JAXB_CONTEXT, context);
        }
        return context;
    }

}