There is a possibility to access Rapla from another java application through the Rapla-API and the Rapla facade. You find a sample that connects to a server in the source distribution under src/org/rapla/examples/RaplaConnectorTest.java

Make sure you have rapla.jar and avalon-framework-4.2.0.jar in your classpath. You may need to adjust the login and server settings.

Here is the source code from Rapla Connector Test

import java.util.Locale;

import org.apache.avalon.framework.logger.ConsoleLogger;
import org.rapla.RaplaMainContainer;
import org.rapla.entities.domain.Allocatable;
import org.rapla.facade.ClientFacade;
import org.rapla.framework.RaplaContext;
import org.rapla.framework.RaplaException;
import org.rapla.framework.StartupEnvironment;

/* Simple demonstration for connecting your app and importing some users. See sources*/
public class RaplaConnectorTest
{
    public static void main(String[] args) {
        final ConsoleLogger logger = new ConsoleLogger( ConsoleLogger.LEVEL_INFO);

        StartupEnvironment env = new SimpleConnectorStartupEnvironment( "localhost", 8050, false, logger);
        try
        {
            RaplaMainContainer container = new RaplaMainContainer( env);
            RaplaContext  context = container.getContext();

            // get an interface to the facade and login
            ClientFacade facade = (ClientFacade)context.lookup(ClientFacade.ROLE);

            if ( !facade.login( "admin", "".toCharArray()) ) {
                throw new RaplaException("Can't login");
            }

            // query resouce
            Allocatable firstResource = facade.getAllocatables() [0] ;
            logger.info( firstResource.getName( Locale.getDefault()));

            // cleanup the Container
            container.dispose();
        }
        catch ( Exception e )
        {
            logger.error("Could not start test ",  e );
        }

    }

}