HttpGetPropertiesDiscoveryStrategy.java

/**
 * Copyright (c) 2008-2011 Sonatype, Inc.
 * All rights reserved. Includes the third-party code listed at http://www.sonatype.com/products/nexus/attributions.
 *
 * This program is free software: you can redistribute it and/or modify it only under the terms of the GNU Affero General
 * Public License Version 3 as published by the Free Software Foundation.
 *
 * This program 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 Affero General Public License Version 3
 * for more details.
 *
 * You should have received a copy of the GNU Affero General Public License Version 3 along with this program.  If not, see
 * http://www.gnu.org/licenses.
 *
 * Sonatype Nexus (TM) Open Source Version is available from Sonatype, Inc. Sonatype and Sonatype Nexus are trademarks of
 * Sonatype, Inc. Apache Maven is a trademark of the Apache Foundation. M2Eclipse is a trademark of the Eclipse Foundation.
 * All other trademarks are the property of their respective owners.
 */
package org.sonatype.nexus.plugins.lvo.strategy;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import org.codehaus.plexus.component.annotations.Component;
import org.sonatype.nexus.plugins.lvo.DiscoveryRequest;
import org.sonatype.nexus.plugins.lvo.DiscoveryResponse;
import org.sonatype.nexus.plugins.lvo.DiscoveryStrategy;
import org.sonatype.nexus.proxy.NoSuchRepositoryException;

/**
 * This is a "remote" strategy, uses HTTP GET to get a Java properties file and get filtered keys from there. It extends
 * the HttpGetDiscoveryStrategy, and assumes that a GETted content is a java.util.Properties file.
 * 
 * @author cstamas
 */
@Component( role = DiscoveryStrategy.class, hint = "http-get-properties" )
public class HttpGetPropertiesDiscoveryStrategy
    extends HttpGetDiscoveryStrategy
{
    public DiscoveryResponse discoverLatestVersion( DiscoveryRequest request )
        throws NoSuchRepositoryException, IOException
    {
        DiscoveryResponse dr = new DiscoveryResponse( request );

        // handle
        InputStream response = handleRequest( getRemoteUrl( request ) );

        if ( response != null )
        {
            Properties properties = new Properties();

            try
            {
                properties.load( response );
            }
            finally
            {
                response.close();
            }

            String keyPrefix = request.getKey() + ".";

            // repack it into response
            for ( Object key : properties.keySet() )
            {
                String keyString = key.toString();

                if ( keyString.startsWith( keyPrefix ) )
                {
                    dr.getResponse().put( key.toString().substring( keyPrefix.length() ), properties.get( key ) );

                    dr.setSuccessful( true );
                }
            }
        }

        return dr;
    }
}