Using Websocket

https://spring.io/guides/gs/messaging-stomp-websocket/

https://docs.spring.io/spring-framework/docs/4.3.x/spring-framework-reference/html/websocket.html

Use WebSocket

https://docs.spring.io/spring-framework/docs/4.3.x/spring-framework-reference/html/websocket.html

• where the client and server need to exchange events at high frequency and with low latency
• when low latency and high frequency are crucial
• Web socket API is too low level (prefer to use STOMP)

HTML5 Web Socket

• create a new web socket instance (specification ws:// wss://
• provide it with the URL
• connection during the initial handshake between the client and the server (underlying TCP/IP)

STOMP (Simple Text Orientated Messaging Protocol)

• a simple, messaging protocol originally created for use in scripting languages with frames inspired by HTTP.
• to address a subset of commonly used messaging patterns
• used over any reliable 2-way streaming network protocol (TCP and WebSocket)
• provide a richer programming model as a sub-protocol
• No need to invent a custom messaging protocol and message format.
• STOMP clients are available including a Java client in the Spring Framework.
• Message brokers such as RabbitMQ, ActiveMQ, and others can be used (optionally) to manage subscriptions and broadcast messages.
• Application logic can be organized in any number of @Controller’s and messages routed to them based on the STOMP destination header vs handling raw WebSocket messages with a single WebSocketHandler for a given connection.
• Use Spring Security to secure messages based on STOMP destinations and message types.
• structure

COMMAND
header1:value1
header2:value2

Body^@

Enable STOMP

import org.springframework.web.socket.config.annotation.EnableWebSocketMessageBroker;
import org.springframework.web.socket.config.annotation.StompEndpointRegistry;

@Configuration@EnableWebSocketMessageBrokerpublicclass WebSocketConfigimplements WebSocketMessageBrokerConfigurer {

@Overridepublicvoid registerStompEndpoints(StompEndpointRegistry registry) {
        registry.addEndpoint("/portfolio").withSockJS();
    }

@Overridepublicvoid configureMessageBroker(MessageBrokerRegistry config) {
        config.setApplicationDestinationPrefixes("/app");
        config.enableSimpleBroker("/topic", "/queue");
    }
}

FLOW

with external broker (RabbitMQ)

텍스트 기반 메시지 프로토콜

https://docs.spring.io/spring-integration/reference/html/stomp.html