jakarta.ws.rs.sse.SseEvent Maven / Gradle / Ivy

/*
 * Copyright (c) 2015, 2019 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.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package jakarta.ws.rs.sse;

/**
 * Base Server Sent Event definition.
 * 
 * This interface provides basic properties of the Server Sent Event, namely ID, Name, and Comment. It also provides
 * access to the Reconnect delay property.
 * 

 * {@code SseEvent} is extended by another two interfaces, {@link InboundSseEvent} and {@link OutboundSseEvent}. The
 * main difference is in how are instances created and how the stored data can be accessed (or provided).
 *
 * @author Marek Potociar
 * @since 2.1
 */
public interface SseEvent {

    /**
     * A "reconnection not set" value for the SSE reconnect delay set via SSE event {@code retry} field.
     */
    long RECONNECT_NOT_SET = -1;

    /**
     * Get event identifier.
     * 

     * Contains value of SSE {@code "id"} field. This field is optional. Method may return {@code null}, if the event
     * identifier is not specified.
     *
     * @return event id.
     */
    String getId();

    /**
     * Get event name.
     * 

     * Contains value of SSE {@code "event"} field. This field is optional. Method may return {@code null}, if the event
     * name is not specified.
     *
     * @return event name, or {@code null} if not set.
     */
    String getName();

    /**
     * Get a comment string that accompanies the event.
     * 

     * Contains value of the comment associated with SSE event. This field is optional. Method may return {@code null}, if
     * the event comment is not specified.
     *
     * @return comment associated with the event.
     */
    String getComment();

    /**
     * Get new connection retry time in milliseconds the event receiver should wait before attempting to reconnect after a
     * connection to the SSE event source is lost.
     * 
     * Contains value of SSE {@code "retry"} field. This field is optional. Method returns {@link #RECONNECT_NOT_SET} if no
     * value has been set.
     *
     * @return reconnection delay in milliseconds or {@link #RECONNECT_NOT_SET} if no value has been set.
     */
    long getReconnectDelay();

    /**
     * Check if the connection retry time has been set in the event.
     *
     * @return {@code true} if new reconnection delay has been set in the event, {@code false} otherwise.
     */
    boolean isReconnectDelaySet();

}