/*

 * Copyright 2007 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Sun designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Sun in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package javax.management.event;

import java.io.IOException;

import java.util.concurrent.Executors;  // for javadoc

import java.util.concurrent.ScheduledFuture;

/**

 * This interface is used to specify a way to receive

 * notifications from a remote MBean server and then to forward the notifications

 * to an {@link EventClient}.

 *

 * @see <a href="package-summary.html#transports">Custom notification

 * transports</a>

 */

public interface EventRelay {

    /**

     * Returns an identifier that is used by this {@code EventRelay} to identify

     * the client when communicating with the {@link EventClientDelegateMBean}.

     * <P> This identifier is obtained by calling

     * {@link EventClientDelegateMBean#addClient(String, Object[], String[])

     * EventClientDelegateMBean.addClient}.

     * <P> It is the {@code EventRelay} that calls {@code EventClientDelegateMBean} to obtain

     * the client identifier because it is the {@code EventRelay} that decides

     * how to get notifications from the {@code EventClientDelegateMBean},

     * by creating the appropriate {@link EventForwarder}.

     *

     * @return A client identifier.

     * @throws IOException If an I/O error occurs when communicating with

     * the {@code EventClientDelegateMBean}.

     */

    public String getClientId() throws IOException;

    /**

     * This method is called by {@link EventClient} to register a callback

     * to receive notifications from an {@link EventClientDelegateMBean} object.

     * A {@code null} value is allowed, which means that the {@code EventClient} suspends

     * reception of notifications, so that the {@code EventRelay} can decide to stop receiving

     * notifications from its {@code EventForwarder}.

     *

     * @param eventReceiver An {@link EventClient} callback to receive

     * events.

     */

    public void setEventReceiver(EventReceiver eventReceiver);

    /**

     * Stops receiving and forwarding notifications and performs any necessary

     * cleanup.  After calling this method, the {@link EventClient} will never

     * call any other methods of this object.

     *

     * @throws IOException If an I/O exception appears.

     *

     * @see EventClient#close

     */

    public void stop() throws IOException;

}