SpringBoot use WebSocket (b)

This article explains how to use the WebSocket how SpringBoot one on one send a message, if you want to learn SpringBoot combined Websocket mass messages, you can go see my previous article: SpringBoot use WebSocket (a)

Import dependence

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-websocket</artifactId>
</dependency>
<dependency>
    <groupId>org.projectlombok</groupId>
    <artifactId>lombok</artifactId>
</dependency>
<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
</dependency>

New Websocket configuration class

/**
 * @author Gjing
 **/
@Configuration
public class WebsocketConfiguration {

    @Bean
    public ServerEndpointExporter serverEndpointExporter() {
        return new ServerEndpointExporter();
    }
}

New message object

/**
 * @author Gjing
 **/
@Data
@Builder
@NoArgsConstructor
@AllArgsConstructor
public class Message {

    private String userId;

    private String message;
}

New websocket Service

/**
 * @author Gjing
 **/
@ServerEndpoint("/test-one")
@Component
@Slf4j
public class MyOneToOneServer {
    /**
     * 用于存放所有在线客户端
     */
    private static Map<String, Session> clients = new ConcurrentHashMap<>();

    private Gson gson = new Gson();

    @OnOpen
    public void onOpen(Session session) {
        log.info("有新的客户端上线: {}", session.getId());
        clients.put(session.getId(), session);
    }

    @OnClose
    public void onClose(Session session) {
        String sessionId = session.getId();
        log.info("有客户端离线: {}", sessionId);
        clients.remove(sessionId);
    }

    @OnError
    public void onError(Session session, Throwable throwable) {
        throwable.printStackTrace();
        if (clients.get(session.getId()) != null) {
            clients.remove(session.getId());
        }
    }

    @OnMessage
    public void onMessage(String message) {
        log.info("收到客户端发来的消息: {}", message);
        this.sendTo(gson.fromJson(message, Message.class));
    }

    /**
     * 发送消息
     *
     * @param message 消息对象
     */
    private void sendTo(Message message) {
        Session s = clients.get(message.getUserId());
        if (s != null) {
            try {
                s.getBasicRemote().sendText(message.getMessage());
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

test

• Two on-line client
  
• Wherein sending a message to a client using another, only you need to bring another client id
  
• Receiving client
  

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This article only describes the most simple business approach, the deeper you deal with your own learning, demo source code address is: springboot-the WebSocket