/*
* Copyright 2002-2016 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.reactive.socket.server;
import java.util.Optional;
import reactor.core.publisher.Mono;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.web.reactive.socket.WebSocketHandler;
import org.springframework.web.server.ServerWebExchange;
/**
* A strategy for upgrading an HTTP request to a WebSocket session depending
* on the underlying network runtime.
*
* <p>Typically there is one such strategy for every {@link ServerHttpRequest}
* and {@link ServerHttpResponse} type except in the case of Servlet containers
* for which the standard Java WebSocket API JSR-356 does not define a way to
* upgrade a request so a custom strategy is needed for every Servlet container.
*
* @author Rossen Stoyanchev
* @since 5.0
*/
public interface RequestUpgradeStrategy {
/**
* Upgrade to a WebSocket session and handle it with the given handler.
* @param exchange the current exchange
* @param webSocketHandler handler for the WebSocket session
* @param subProtocol the selected sub-protocol got the handler
* @return completion {@code Mono<Void>} to indicate the outcome of the
* WebSocket session handling.
*/
@SuppressWarnings("OptionalUsedAsFieldOrParameterType")
Mono<Void> upgrade(ServerWebExchange exchange, WebSocketHandler webSocketHandler,
Optional<String> subProtocol);
}