application/src/main/java/eclipselink/example/mysports/application/admin/AdminMetadataSource.java

/*******************************************************************************
 * Copyright (c) 2010-2013 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 2.3 - MySports Demo Bug 344608
 ******************************************************************************/
package eclipselink.example.mysports.application.admin;

import static eclipselink.example.mysports.application.MySportsConfig.LEAGUE_CONTEXT;

import java.util.Map;

import org.eclipse.persistence.config.PersistenceUnitProperties;
import org.eclipse.persistence.exceptions.ValidationException;
import org.eclipse.persistence.internal.jpa.metadata.xml.XMLEntityMappings;
import org.eclipse.persistence.jpa.metadata.MetadataSource;
import org.eclipse.persistence.jpa.metadata.XMLMetadataSource;
import org.eclipse.persistence.logging.SessionLog;

/**
 * {@link MetadataSource} which using REST calls to retrieve the league (tenant)
 * specific mappings from the MySports Admin application.
 * <p>
 * If the Admin application can not be reached a warning message is logged and
 * the contained 'local-eclipselink-orm.xml' is returned.
 * 
 * @author dclarke
 * @since EclipseLink 2.3.0
 */
public class AdminMetadataSource extends XMLMetadataSource {

    private AdminServerConnector connector;
    
    public AdminMetadataSource(AdminServerConnector connector) {
        super();
        this.connector = connector;
    }

    AdminServerConnector getConnector() {
        return connector;
    }

    /**
     * Default local resource. Only used when admin service cannot be accessed.
     */
    public static final String LOCAL_ECLIPSELINK_ORM = "META-INF/local-eclipselink-orm.xml";

    @Override
    public XMLEntityMappings getEntityMappings(Map<String, Object> properties, ClassLoader classLoader, SessionLog log) {
        String leagueId = (String) properties.get(LEAGUE_CONTEXT);

        if (leagueId != null) {
            if (connector != null) {
                properties.put(PersistenceUnitProperties.METADATA_SOURCE_XML_URL, getConnector().getOrmURL(leagueId));
            }
            try {
                return super.getEntityMappings(properties, classLoader, log);
            } catch (ValidationException ve) {
            } catch (NullPointerException npe) {

            }

            properties.remove(PersistenceUnitProperties.METADATA_SOURCE_XML_URL);
            properties.put(PersistenceUnitProperties.METADATA_SOURCE_XML_FILE, LOCAL_ECLIPSELINK_ORM);
            return super.getEntityMappings(properties, classLoader, log);
        }
        return null;
    }

}