Spring Boot

application.properties

netty-socket-io.hostname=localhost
netty-socket-io.port=9092
netty-socket-io.ping-timeout=60000
netty-socket-io.ping-interval=25000

application.yml

Just adding the properties/yml is enough to run the server with default settings. If you want to add SocketIOServer bean exclude the default server

Custom SocketIOServer Bean

@Configuration
public class SocketIOConfig {
    
    @Bean
    public SocketIOServer socketIOServer() {
        Configuration config = new Configuration();
        config.setHostname("localhost");
        config.setPort(9092);
        return new SocketIOServer(config);
    }
}

Main Application

@SpringBootApplication
public class SpringBootMainApplication implements CommandLineRunner {
    
    private static final Logger log = LoggerFactory.getLogger(SpringBootMainApplication.class);
    
    @Autowired
    private SocketIOServer server;
    
    public static void main(String[] args) {
        SpringApplication.run(SpringBootMainApplication.class, args);
    }
    
    @Override
    public void run(String... args) throws Exception {
        // Add event listeners
        server.addEventListener("chatevent", ChatMessage.class, (client, data, ackRequest) -> {
            server.getBroadcastOperations().sendEvent("chatevent", data);
        });
        
        server.start();
        log.info("Socket.IO server started on port {}", server.getConfiguration().getPort());
    }
}

Event Handler with Annotations

You can use annotations to define event handlers:

@Component
public class ChatEventHandler {
    
    @Autowired
    private SocketIOServer server;
    
    @OnConnect
    public void onConnect(SocketIOClient client) {
        log.info("Client connected: {}", client.getSessionId());
    }
    
    @OnDisconnect
    public void onDisconnect(SocketIOClient client) {
        log.info("Client disconnected: {}", client.getSessionId());
    }
    
    @OnEvent("chatevent")
    public void onChatEvent(SocketIOClient client, ChatMessage data, AckRequest ackRequest) {
        server.getBroadcastOperations().sendEvent("chatevent", data);
    }
}

Exception Handling

@Configuration
public class CustomizedSocketIOConfiguration {
    
    @Bean
    public ExceptionListener exceptionListener() {
        return new ExceptionListener() {
            @Override
            public void onEventException(Exception e, List<Object> args, SocketIOClient client) {
                log.error("Event exception", e);
            }
            
            @Override
            public void onDisconnectException(Exception e, SocketIOClient client) {
                log.error("Disconnect exception", e);
            }
            
            // ... implement other methods
        };
    }
}

Full Example

See the complete example in the netty-socketio-examples-spring-boot-base module.