001/*
002 * Copyright 2002-2018 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 * @param <T> the payload type
025 */
026public interface WebSocketMessage<T> {
027
028        /**
029         * Return the message payload (never {@code null}).
030         */
031        T getPayload();
032
033        /**
034         * Return the number of bytes contained in the message.
035         */
036        int getPayloadLength();
037
038        /**
039         * When partial message support is available and requested via
040         * {@link org.springframework.web.socket.WebSocketHandler#supportsPartialMessages()},
041         * this method returns {@code true} if the current message is the last part of the
042         * complete WebSocket message sent by the client. Otherwise {@code false} is returned
043         * if partial message support is either not available or not enabled.
044         */
045        boolean isLast();
046
047}