Fix: 프론트 요청사항에 따른 WebRTC 시그널링 서버 수정 (#241)

src/main/java/com/back/global/websocket/webrtc/controller/WebRTCSignalingController.java

@@ -6,6 +6,7 @@
 import com.back.global.websocket.dto.WebSocketSessionInfo;
 import com.back.global.websocket.service.WebSocketSessionManager;
 import com.back.global.websocket.util.WebSocketAuthHelper;
+import com.back.global.websocket.webrtc.dto.WebRTCErrorResponse;
 import com.back.global.websocket.webrtc.dto.media.WebRTCMediaStateResponse;
 import com.back.global.websocket.webrtc.dto.media.WebRTCMediaToggleRequest;
 import com.back.global.websocket.webrtc.dto.signal.*;
@@ -16,7 +17,6 @@
 import org.springframework.messaging.handler.annotation.MessageExceptionHandler;
 import org.springframework.messaging.handler.annotation.MessageMapping;
 import org.springframework.messaging.handler.annotation.Payload;
-import org.springframework.messaging.simp.SimpMessageHeaderAccessor;
 import org.springframework.messaging.simp.SimpMessagingTemplate;
 import org.springframework.stereotype.Controller;
 import org.springframework.validation.annotation.Validated;
@@ -35,13 +35,10 @@ public class WebRTCSignalingController {
 
     // WebRTC Offer 메시지 처리
     @MessageMapping("/webrtc/offer")
-    public void handleOffer(@Validated @Payload WebRTCOfferRequest request,
-                            SimpMessageHeaderAccessor headerAccessor,
-                            Principal principal) {
+    public void handleOffer(@Validated @Payload WebRTCOfferRequest request, Principal principal) {
         CustomUserDetails userDetails = WebSocketAuthHelper.extractUserDetails(principal);
         if (userDetails == null) {
-            errorHelper.sendUnauthorizedError(headerAccessor.getSessionId());
-            return;
+            throw new CustomException(ErrorCode.UNAUTHORIZED);
         }
 
         Long fromUserId = userDetails.getUserId();
@@ -66,13 +63,10 @@ public void handleOffer(@Validated @Payload WebRTCOfferRequest request,
 
     // WebRTC Answer 메시지 처리
     @MessageMapping("/webrtc/answer")
-    public void handleAnswer(@Validated @Payload WebRTCAnswerRequest request,
-                             SimpMessageHeaderAccessor headerAccessor,
-                             Principal principal) {
+    public void handleAnswer(@Validated @Payload WebRTCAnswerRequest request, Principal principal) {
         CustomUserDetails userDetails = WebSocketAuthHelper.extractUserDetails(principal);
         if (userDetails == null) {
-            errorHelper.sendUnauthorizedError(headerAccessor.getSessionId());
-            return;
+            throw new CustomException(ErrorCode.UNAUTHORIZED);
         }
 
         Long fromUserId = userDetails.getUserId();
@@ -97,13 +91,10 @@ public void handleAnswer(@Validated @Payload WebRTCAnswerRequest request,
 
     // ICE Candidate 메시지 처리
     @MessageMapping("/webrtc/ice-candidate")
-    public void handleIceCandidate(@Validated @Payload WebRTCIceCandidateRequest request,
-                                   SimpMessageHeaderAccessor headerAccessor,
-                                   Principal principal) {
+    public void handleIceCandidate(@Validated @Payload WebRTCIceCandidateRequest request, Principal principal) {
         CustomUserDetails userDetails = WebSocketAuthHelper.extractUserDetails(principal);
         if (userDetails == null) {
-            errorHelper.sendUnauthorizedError(headerAccessor.getSessionId());
-            return;
+            throw new CustomException(ErrorCode.UNAUTHORIZED);
         }
 
         Long fromUserId = userDetails.getUserId();
@@ -127,13 +118,10 @@ public void handleIceCandidate(@Validated @Payload WebRTCIceCandidateRequest req
 
     // 미디어 상태 토글 처리 (방 전체에 상태 공유)
     @MessageMapping("/webrtc/media/toggle")
-    public void handleMediaToggle(@Validated @Payload WebRTCMediaToggleRequest request,
-                                  SimpMessageHeaderAccessor headerAccessor,
-                                  Principal principal) {
+    public void handleMediaToggle(@Validated @Payload WebRTCMediaToggleRequest request, Principal principal) {
         CustomUserDetails userDetails = WebSocketAuthHelper.extractUserDetails(principal);
         if (userDetails == null) {
-            errorHelper.sendUnauthorizedError(headerAccessor.getSessionId());
-            return;
+            throw new CustomException(ErrorCode.UNAUTHORIZED);
         }
 
         Long userId = userDetails.getUserId();
@@ -150,15 +138,41 @@ public void handleMediaToggle(@Validated @Payload WebRTCMediaToggleRequest reque
 
     // WebRTC 시그널링 처리 중 발생하는 CustomException 처리
     @MessageExceptionHandler(CustomException.class)
-    public void handleCustomException(CustomException e, SimpMessageHeaderAccessor headerAccessor) {
-        log.warn("WebRTC 시그널링 오류 발생: {}", e.getMessage());
-        errorHelper.sendCustomExceptionToUser(headerAccessor.getSessionId(), e);
+    public void handleCustomException(CustomException e, Principal principal) {
+        if (principal == null) {
+            log.warn("인증 정보 없는 사용자의 WebRTC 오류: {}", e.getMessage());
+            return;
+        }
+
+        log.warn("WebRTC 시그널링 오류 발생 (to {}): {}", principal.getName(), e.getMessage());
+
+        WebRTCErrorResponse errorResponse = WebRTCErrorResponse.from(e);
+
+        messagingTemplate.convertAndSendToUser(
+                principal.getName(), // 에러를 발생시킨 사람의 username
+                "/queue/webrtc",
+                errorResponse
+        );
     }
 
     // 예상치 못한 모든 Exception 처리
     @MessageExceptionHandler(Exception.class)
-    public void handleGeneralException(Exception e, SimpMessageHeaderAccessor headerAccessor) {
-        log.error("WebRTC 시그널링 처리 중 예상치 못한 오류 발생", e);
-        errorHelper.sendGenericErrorToUser(headerAccessor.getSessionId(), e, "시그널링 처리 중 오류가 발생했습니다.");
+    public void handleGeneralException(Exception e, Principal principal) { // headerAccessor -> Principal
+        if (principal == null) {
+            log.error("WebRTC 처리 중 인증 정보 없는 사용자의 예외 발생", e);
+            return;
+        }
+
+        log.error("WebRTC 시그널링 처리 중 예상치 못한 오류 발생 (to {})", principal.getName(), e);
+
+        // CustomException으로 감싸서 일관된 형식의 에러 DTO를 생성
+        CustomException customException = new CustomException(ErrorCode.WS_INTERNAL_ERROR);
+        WebRTCErrorResponse errorResponse = WebRTCErrorResponse.from(customException);
+
+        messagingTemplate.convertAndSendToUser(
+                principal.getName(),
+                "/queue/webrtc",
+                errorResponse
+        );
     }
 }

src/main/java/com/back/global/websocket/webrtc/dto/WebRTCErrorResponse.java

@@ -0,0 +1,20 @@
+package com.back.global.websocket.webrtc.dto;
+
+import com.back.global.exception.CustomException;
+import java.time.LocalDateTime;
+
+public record WebRTCErrorResponse(
+        String type,
+        ErrorPayload error,
+        LocalDateTime timestamp
+) {
+    public record ErrorPayload(String code, String message) {}
+
+    public static WebRTCErrorResponse from(CustomException e) {
+        return new WebRTCErrorResponse(
+                "ERROR",
+                new ErrorPayload(e.getErrorCode().getCode(), e.getMessage()),
+                LocalDateTime.now()
+        );
+    }
+}

src/main/java/com/back/global/websocket/webrtc/dto/signal/SdpData.java

@@ -0,0 +1,3 @@
+package com.back.global.websocket.webrtc.dto.signal;
+
+public record SdpData(String type, String sdp) {}

src/main/java/com/back/global/websocket/webrtc/dto/signal/WebRTCAnswerRequest.java

@@ -6,7 +6,7 @@
 public record WebRTCAnswerRequest(
         @NotNull Long roomId,
         @NotNull Long targetUserId,
-        @NotNull String sdp,
+        @NotNull SdpData sdp,
         @NotNull WebRTCMediaType mediaType
 ) {
 }

src/main/java/com/back/global/websocket/webrtc/dto/signal/WebRTCOfferRequest.java

@@ -6,7 +6,7 @@
 public record WebRTCOfferRequest(
         @NotNull Long roomId,
         @NotNull Long targetUserId,
-        @NotNull String sdp,
+        @NotNull SdpData sdp,
         @NotNull WebRTCMediaType mediaType
 ) {
 }

src/main/java/com/back/global/websocket/webrtc/dto/signal/WebRTCSignalResponse.java

@@ -9,7 +9,7 @@ public record WebRTCSignalResponse(
         Long fromUserId,
         Long targetUserId,
         Long roomId,
-        String sdp,
+        SdpData sdp,
         WebRTCMediaType mediaType,
         String candidate,
         String sdpMid,
@@ -23,7 +23,7 @@ public static WebRTCSignalResponse offerOrAnswer(
             Long fromUserId,
             Long targetUserId,
             Long roomId,
-            String sdp,
+            SdpData sdp,
             WebRTCMediaType mediaType
     ) {
         return new WebRTCSignalResponse(