java source code of EchoWebSocketHandler

/*
 * 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 playground;

import java.time.Duration;

import reactor.core.publisher.Mono;

import org.springframework.web.reactive.socket.WebSocketHandler;
import org.springframework.web.reactive.socket.WebSocketMessage;
import org.springframework.web.reactive.socket.WebSocketSession;

/**
 * WebSocketHandler that echoes the input with a delay of 2 seconds.
 */
public class EchoWebSocketHandler implements WebSocketHandler {

	@Override
	public Mono<Void> handle(WebSocketSession session) {
		// Use retain() for Reactor Netty
		return session.send(session.receive().doOnNext(WebSocketMessage::retain).delay(Duration.ofSeconds(2)));
	}
}