001/*
002 * Copyright 2002-2016 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.web.socket;
018
019/**
020 * A message that can be handled or sent on a WebSocket connection.
021 *
022 * @author Rossen Stoyanchev
023 * @since 4.0
024 */
025public interface WebSocketMessage<T> {
026
027        /**
028         * Return the message payload (never {@code null}).
029         */
030        T getPayload();
031
032        /**
033         * Return the number of bytes contained in the message.
034         */
035        int getPayloadLength();
036
037        /**
038         * When partial message support is available and requested via
039         * {@link org.springframework.web.socket.WebSocketHandler#supportsPartialMessages()},
040         * this method returns {@code true} if the current message is the last part of the
041         * complete WebSocket message sent by the client. Otherwise {@code false} is returned
042         * if partial message support is either not available or not enabled.
043         */
044        boolean isLast();
045
046}