foundation/org.eclipse.persistence.core/src/main/java/org/eclipse/persistence/internal/sessions/coordination/ConnectToHostCommand.java

/*
 * Copyright (c) 1998, 2021 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0 which is available at
 * http://www.eclipse.org/legal/epl-2.0,
 * or the Eclipse Distribution License v. 1.0 which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: EPL-2.0 OR BSD-3-Clause
 */

// Contributors:
//     Oracle - initial API and implementation from Oracle TopLink
package org.eclipse.persistence.internal.sessions.coordination;

import org.eclipse.persistence.internal.sessions.AbstractSession;
import org.eclipse.persistence.sessions.coordination.RemoteCommandManager;

/**
 * <p>
 * <b>Purpose</b>: This class provides an implementation of an internal RCM Command.
 * </p>
 * <p>
 * <b>Description</b>: This command is used by the RCM when it receives a connection
 * from a remote service. It adds the connection to its own list, and then sends this command
 * back to the remote service  to establish the backward connection from the remote service to
 * this service, accompanying the command with a reference to this own service id.  The
 * remote service can then create a connection using the service id stored in the command and
 * add the connection to its connection list.
 * </p>
 * @see org.eclipse.persistence.sessions.coordination.TransportManager
 * @author Steven Vo
 * @since OracleAS TopLink 10<i>g</i> (9.0.4)
 */
public class ConnectToHostCommand extends RCMCommand {

    /**
     * INTERNAL:
     * Executed on the RCM when received. Just add the remote object reference to
     * the connection list.
     */
    @Override
    public void executeWithRCM(RemoteCommandManager rcm) {
        RemoteConnection connection = rcm.getTransportManager().createConnection(this.getServiceId());
        // null is returned from createConnection if connection cannot be created
        if (connection != null) {
            rcm.getTransportManager().getConnectionsToExternalServices().put(connection.getServiceId().getId(), connection);
        }
    }

    @Override
    public void executeWithSession(AbstractSession session) {
        // Internal RCM commands do not implement this method
    }
}