feat: WebSocket 로깅 인터셉터 작성 (#635)

* feat: WebSocket 로깅 인터셉터 작성

* refactor: Principal 명시적 형 변환 대신 null 체크하여 형 변환

Author: whqtker

src/main/java/com/example/solidconnection/chat/config/StompWebSocketConfig.java

@@ -5,6 +5,7 @@
 import com.example.solidconnection.chat.config.StompProperties.OutboundProperties;
 import com.example.solidconnection.security.config.CorsProperties;
 import java.util.List;
+import java.util.Optional;
 import lombok.RequiredArgsConstructor;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.messaging.simp.config.ChannelRegistration;
@@ -24,6 +25,7 @@ public class StompWebSocketConfig implements WebSocketMessageBrokerConfigurer {
     private final CorsProperties corsProperties;
     private final WebSocketHandshakeInterceptor webSocketHandshakeInterceptor;
     private final CustomHandshakeHandler customHandshakeHandler;
+    private final Optional<WebSocketLoggingInterceptor> webSocketLoggingInterceptor;
 
     @Override
     public void registerStompEndpoints(StompEndpointRegistry registry) {
@@ -39,7 +41,12 @@ public void registerStompEndpoints(StompEndpointRegistry registry) {
     @Override
     public void configureClientInboundChannel(ChannelRegistration registration) {
         InboundProperties inboundProperties = stompProperties.threadPool().inbound();
-        registration.interceptors(stompHandler).taskExecutor().corePoolSize(inboundProperties.corePoolSize()).maxPoolSize(inboundProperties.maxPoolSize()).queueCapacity(inboundProperties.queueCapacity());
+        webSocketLoggingInterceptor.ifPresent(registration::interceptors);
+        registration.interceptors(stompHandler)
+                .taskExecutor()
+                .corePoolSize(inboundProperties.corePoolSize())
+                .maxPoolSize(inboundProperties.maxPoolSize())
+                .queueCapacity(inboundProperties.queueCapacity());
     }
 
     @Override

src/main/java/com/example/solidconnection/chat/config/WebSocketLoggingInterceptor.java

@@ -0,0 +1,55 @@
+package com.example.solidconnection.chat.config;
+
+import com.example.solidconnection.security.authentication.TokenAuthentication;
+import com.example.solidconnection.security.userdetails.SiteUserDetails;
+import java.security.Principal;
+import lombok.extern.slf4j.Slf4j;
+import org.springframework.context.annotation.Profile;
+import org.springframework.messaging.Message;
+import org.springframework.messaging.MessageChannel;
+import org.springframework.messaging.simp.stomp.StompCommand;
+import org.springframework.messaging.simp.stomp.StompHeaderAccessor;
+import org.springframework.messaging.support.ChannelInterceptor;
+import org.springframework.stereotype.Component;
+
+@Slf4j
+@Component
+@Profile("dev")
+public class WebSocketLoggingInterceptor implements ChannelInterceptor {
+
+    @Override
+    public Message<?> preSend(Message<?> message, MessageChannel channel) {
+        StompHeaderAccessor accessor = StompHeaderAccessor.wrap(message);
+        StompCommand command = accessor.getCommand();
+
+        if (command != null) {
+            Long userId = extractUserId(accessor);
+            String destination = accessor.getDestination();
+            logStompMessage(command, destination, userId);
+        }
+
+        return message;
+    }
+
+    private void logStompMessage(StompCommand command, String destination, Long userId) {
+        switch (command) {
+            case CONNECT -> log.info("[WEBSOCKET] CONNECT userId = {}", userId);
+            case SUBSCRIBE -> log.info("[WEBSOCKET] SUBSCRIBE {} userId = {}", destination, userId);
+            case SEND -> log.info("[WEBSOCKET] SEND {} userId = {}", destination, userId);
+            case DISCONNECT -> log.info("[WEBSOCKET] DISCONNECT userId = {}", userId);
+            default -> {
+            }
+        }
+    }
+
+    private Long extractUserId(StompHeaderAccessor accessor) {
+        Principal user = accessor.getUser();
+        if (user instanceof TokenAuthentication tokenAuth) {
+            Object principal = tokenAuth.getPrincipal();
+            if (principal instanceof SiteUserDetails details) {
+                return details.getSiteUser().getId();
+            }
+        }
+        return null;
+    }
+}