org.springframework.web.socket.messaging.SubProtocolHandler Maven / Gradle / Ivy
/*
* Copyright 2002-2013 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.springframework.web.socket.messaging;
import java.util.List;
import org.springframework.messaging.Message;
import org.springframework.messaging.MessageChannel;
import org.springframework.web.socket.CloseStatus;
import org.springframework.web.socket.WebSocketMessage;
import org.springframework.web.socket.WebSocketSession;
/**
* A contract for handling WebSocket messages as part of a higher level protocol, referred
* to as "sub-protocol" in the WebSocket RFC specification. Handles both
* {@link WebSocketMessage}s from a client as well as {@link Message}s to a client.
*
* Implementations of this interface can be configured on a
* {@link SubProtocolWebSocketHandler} which selects a sub-protocol handler to delegate
* messages to based on the sub-protocol requested by the client through the
* {@code Sec-WebSocket-Protocol} request header.
*
* @author Andy Wilkinson
* @author Rossen Stoyanchev
*
* @since 4.0
*/
public interface SubProtocolHandler {
/**
* Return the list of sub-protocols supported by this handler, never {@code null}.
*/
List getSupportedProtocols();
/**
* Handle the given {@link WebSocketMessage} received from a client.
* @param session the client session
* @param message the client message
* @param outputChannel an output channel to send messages to
*/
void handleMessageFromClient(WebSocketSession session, WebSocketMessage message,
MessageChannel outputChannel) throws Exception;
/**
* Handle the given {@link Message} to the client associated with the given WebSocket
* session.
* @param session the client session
* @param message the client message
*/
void handleMessageToClient(WebSocketSession session, Message message) throws Exception;
/**
* Resolve the session id from the given message or return {@code null}.
* @param message the message to resolve the session id from
*/
String resolveSessionId(Message message);
/**
* Invoked after a {@link WebSocketSession} has started.
* @param session the client session
* @param outputChannel a channel
*/
void afterSessionStarted(WebSocketSession session, MessageChannel outputChannel) throws Exception;
/**
* Invoked after a {@link WebSocketSession} has ended.
* @param session the client session
* @param closeStatus the reason why the session was closed
* @param outputChannel a channel
*/
void afterSessionEnded(WebSocketSession session, CloseStatus closeStatus,
MessageChannel outputChannel) throws Exception;
}