OcppWebSocketUpgrader.java

package de.rwth.idsg.steve.ocpp.ws;

import de.rwth.idsg.steve.ocpp.OcppVersion;
import de.rwth.idsg.steve.ocpp.ws.ocpp12.Ocpp12WebSocketEndpoint;
import de.rwth.idsg.steve.ocpp.ws.ocpp15.Ocpp15WebSocketEndpoint;
import de.rwth.idsg.steve.repository.ChargePointRepository;
import org.eclipse.jetty.websocket.api.WebSocketPolicy;
import org.eclipse.jetty.websocket.server.WebSocketServerFactory;
import org.springframework.http.server.ServerHttpRequest;
import org.springframework.http.server.ServerHttpResponse;
import org.springframework.web.socket.WebSocketExtension;
import org.springframework.web.socket.WebSocketHandler;
import org.springframework.web.socket.server.HandshakeFailureException;
import org.springframework.web.socket.server.jetty.JettyRequestUpgradeStrategy;

import java.security.Principal;
import java.util.List;
import java.util.Map;

/**
 * @author Sevket Goekay <goekay@dbis.rwth-aachen.de>
 * @since 13.03.2015
 */
public class OcppWebSocketUpgrader extends JettyRequestUpgradeStrategy {
    private final Ocpp12WebSocketEndpoint ocpp12WebSocketEndpoint;
    private final Ocpp15WebSocketEndpoint ocpp15WebSocketEndpoint;
    private final ChargePointRepository chargePointRepository;

    public OcppWebSocketUpgrader(WebSocketPolicy policy,
                                 Ocpp12WebSocketEndpoint ocpp12WebSocketEndpoint,
                                 Ocpp15WebSocketEndpoint ocpp15WebSocketEndpoint,
                                 ChargePointRepository chargePointRepository) {

        super(new WebSocketServerFactory(policy));
        this.ocpp12WebSocketEndpoint = ocpp12WebSocketEndpoint;
        this.ocpp15WebSocketEndpoint = ocpp15WebSocketEndpoint;
        this.chargePointRepository = chargePointRepository;
    }

    @Override
    public void upgrade(ServerHttpRequest request, ServerHttpResponse response,
                        String selectedProtocol, List<WebSocketExtension> selectedExtensions, Principal user,
                        WebSocketHandler wsHandler, Map<String, Object> attributes) throws HandshakeFailureException {

        // -------------------------------------------------------------------------
        // 1. Check the chargeBoxId
        // -------------------------------------------------------------------------

        String chargeBoxId = getLastBitFromUrl(request.getURI().getPath());
        if (chargePointRepository.isRegistered(chargeBoxId)) {
            attributes.put(AbstractWebSocketEndpoint.CHARGEBOX_ID_KEY, chargeBoxId);
        } else {
            throw new HandshakeFailureException("ChargeBoxId '" + chargeBoxId + "' is not registered");
        }

        // -------------------------------------------------------------------------
        // 2. Route according to the selected protocol
        // -------------------------------------------------------------------------

        AbstractWebSocketEndpoint webSocketHandler;
        if (selectedProtocol == null) {
            throw new HandshakeFailureException("No protocol (OCPP version) is specified.");

        } else if (OcppVersion.V_12.getValue().equals(selectedProtocol)) {
            webSocketHandler = ocpp12WebSocketEndpoint;

        } else if (OcppVersion.V_15.getValue().equals(selectedProtocol)) {
            webSocketHandler = ocpp15WebSocketEndpoint;

        } else {
            throw new HandshakeFailureException("Requested protocol '" + selectedProtocol + "' is not supported");
        }

        super.upgrade(request, response, selectedProtocol, selectedExtensions, user, webSocketHandler, attributes);
    }

    /**
     * Taken from: http://stackoverflow.com/a/4050276
     */
    private static String getLastBitFromUrl(final String url) {
        return url.replaceFirst(".*/([^/?]+).*", "$1");
    }
}