fix : sessionId NullPointerException 에러 수정

ServerlessFunction/src/main/java/com/mzc/secondproject/serverless/domain/speaking/handler/websocket/SpeakingHandler.java → ServerlessFunction/src/main/java/com/mzc/secondproject/serverless/domain/speaking/handler/SpeakingHandler.java

@@ -1,4 +1,4 @@
-package com.mzc.secondproject.serverless.domain.speaking.handler.websocket;
+package com.mzc.secondproject.serverless.domain.speaking.handler;
 
 import com.amazonaws.services.lambda.runtime.Context;
 import com.amazonaws.services.lambda.runtime.RequestHandler;
@@ -9,6 +9,7 @@
 import com.google.gson.JsonObject;
 import com.google.gson.JsonParser;
 import com.mzc.secondproject.serverless.common.util.JwtUtil;
+import com.mzc.secondproject.serverless.domain.speaking.dto.response.SpeakingResponse;
 import com.mzc.secondproject.serverless.domain.speaking.service.SpeakingService;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -102,7 +103,7 @@ private APIGatewayProxyResponseEvent handleChat(String userId, String body) {
         String audio = request.has("audio") ? request.get("audio").getAsString() : null;
         String text = request.has("text") ? request.get("text").getAsString() : null;
 
-        SpeakingService.SpeakingResponse result;
+        SpeakingResponse result;
 
         if (audio != null && !audio.isEmpty()) {
             // 음성 입력 처리
@@ -134,7 +135,7 @@ private APIGatewayProxyResponseEvent handleReset(String userId, String body) {
         }
 
         JsonObject request = JsonParser.parseString(body).getAsJsonObject();
-        String sessionId = request.has("sessionId") ? request.get("sessionId").getAsString() : null;
+        String sessionId = getStringOrNull(request, "sessionId");
 
         if (sessionId == null || sessionId.isEmpty()) {
             return response(400, Map.of("error", "sessionId is required"));
@@ -176,4 +177,6 @@ private APIGatewayProxyResponseEvent response(int statusCode, Map<String, Object
                 .withHeaders(CORS_HEADERS)
                 .withBody(gson.toJson(body));
     }
+
+
 }

ServerlessFunction/src/main/java/com/mzc/secondproject/serverless/domain/speaking/service/SpeakingService.java

@@ -5,6 +5,7 @@
 import com.mzc.secondproject.serverless.common.config.EnvConfig;
 import com.mzc.secondproject.serverless.common.service.PollyService;
 import com.mzc.secondproject.serverless.domain.opic.service.TranscribeProxyService;
+import com.mzc.secondproject.serverless.domain.speaking.dto.response.SpeakingResponse;
 import com.mzc.secondproject.serverless.domain.speaking.model.SpeakingSession;
 import com.mzc.secondproject.serverless.domain.speaking.repository.SpeakingSessionRepository;
 
@@ -82,7 +83,7 @@ public SpeakingResponse processVoiceInput(String sessionId, String userId, Strin
         logger.info("Step 1: Transcribing audio...");
         TranscribeProxyService.TranscribeResult sttResult = transcribeService.transcribe(
                 audioBase64,
-                sessionId,
+                session.getSessionId(),
                 "en-US"
         );
         String userText = sttResult.transcript();
@@ -314,6 +315,7 @@ private List<Message> parseHistory(String historyJson) {
         return history;
     }
 
+
     /**
      * 히스토리 JSON 변환
      */
@@ -328,18 +330,9 @@ private String toJson(List<Message> history) {
         return array.toString();
     }
 
-    // ==================== Inner Classes ====================
-
-    private record Message(String role, String content) {}
-
     /**
-     * Speaking 응답 DTO
+     * 대화 메시지 (히스토리용)
      */
-    public record SpeakingResponse(
-            String sessionId,         // 세션 ID (다음 요청에 사용)
-            String userTranscript,    // 사용자가 말한 내용 (STT 결과)
-            String aiText,            // AI 응답 텍스트
-            String aiAudioUrl,        // AI 응답 음성 URL (Polly)
-            double confidence         // STT 신뢰도comp
-    ) {}
+    private record Message(String role, String content) {}
+
 }

ServerlessFunction/src/main/java/com/mzc/secondproject/serverless/domain/user/dto/response/ProfileResponse.java

@@ -29,7 +29,7 @@ public static ProfileResponse from(User user) {
 				.email(user.getEmail())
 				.nickname(user.getNickname())
 				.level(user.getLevel())
-				.profileUrl(user.getProfileUrl())
+				.profileUrl(user.getProfileUrlForResponse())
 				.createdAt(user.getCreatedAt())
 				.updatedAt(user.getUpdatedAt())
 				.build();

ServerlessFunction/src/main/java/com/mzc/secondproject/serverless/domain/user/handler/UserHandler.java

@@ -59,9 +59,20 @@ private APIGatewayProxyResponseEvent getMyProfile(
 			APIGatewayProxyRequestEvent request,
 			String userId // cognitoSub
 	) {
-
 		User user = userService.getProfile(userId, request);
-		ProfileResponse response = ProfileResponse.from(user);
+
+		// profileUrl을 Presigned URL로 변환
+		String presignedUrl = userService.getPresignedProfileUrl(user.getProfileUrl());
+
+		ProfileResponse response = ProfileResponse.builder()
+				.userId(user.getCognitoSub())
+				.email(user.getEmail())
+				.nickname(user.getNickname())
+				.level(user.getLevel())
+				.profileUrl(presignedUrl)  // Presigned URL 사용
+				.createdAt(user.getCreatedAt())
+				.updatedAt(user.getUpdatedAt())
+				.build();
 
 		return ResponseGenerator.ok(user.getNickname() + " 환영합니다!", response);
 	}

ServerlessFunction/src/main/java/com/mzc/secondproject/serverless/domain/user/model/User.java

@@ -27,11 +27,13 @@ public class User {
 	private String nickname;
 	private String level;
 	private String profileUrl;
+	private String profileUrlForResponse;
 	private String createdAt;
 	private String updatedAt;
 	private String lastLoginAt;
 	private Long ttl;
-
+
+
 	/**
 	 * 신규 사용자 생성
 	 * - Lazy Registration 적용: 최초 프로필 조회 시 DynamoDB에 저장
@@ -114,7 +116,12 @@ public void updateProfileUrl(String newProfileUrl) {
 		this.profileUrl = newProfileUrl;
 		this.updatedAt = Instant.now().toString();
 	}
-
+
+	@DynamoDbIgnore
+	public String getProfileUrlForResponse() {
+		return profileUrlForResponse != null ? profileUrlForResponse : profileUrl;
+	}
+
 	public void updateLastLoginAt() {
 		this.lastLoginAt = Instant.now().toString();
 	}

ServerlessFunction/src/main/java/com/mzc/secondproject/serverless/domain/user/service/UserService.java

@@ -7,8 +7,10 @@
 import com.mzc.secondproject.serverless.domain.user.repository.UserRepository;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
+import software.amazon.awssdk.services.s3.model.GetObjectRequest;
 import software.amazon.awssdk.services.s3.model.PutObjectRequest;
 import software.amazon.awssdk.services.s3.presigner.S3Presigner;
+import software.amazon.awssdk.services.s3.presigner.model.GetObjectPresignRequest;
 import software.amazon.awssdk.services.s3.presigner.model.PresignedPutObjectRequest;
 import software.amazon.awssdk.services.s3.presigner.model.PutObjectPresignRequest;
 
@@ -52,18 +54,53 @@ public UserService(UserRepository userRepository) {
 	 * @return User 객체
 	 */
 	public User getProfile(String userId, APIGatewayProxyRequestEvent request) {
-
-		return userRepository.findByCognitoSub(userId)
-				.map(user -> {
-					// 정상 DB에서 조회 완료
-					user.updateLastLoginAt();
-					userRepository.update(user);
-					return user;
+
+		User user = userRepository.findByCognitoSub(userId)
+				.map(u -> {
+					u.updateLastLoginAt();
+					userRepository.update(u);
+					return u;
 				})
-				.orElseGet(() -> {
-					// PostConfirmation 실패 대비 fallback
-					return createUserFromRequest(userId, request);
-				});
+				.orElseGet(() -> createUserFromRequest(userId, request));
+
+		// 프로필 URL을 Presigned URL로 변환
+		String presignedProfileUrl = getPresignedProfileUrl(user.getProfileUrl());
+		user.setProfileUrlForResponse(presignedProfileUrl);  // 응답용으로만 설정
+
+		return user;
+	}
+
+	public String getPresignedProfileUrl(String s3Url) {
+		if (s3Url == null || s3Url.isEmpty()) {
+			return generateGetPresignedUrl("profile/default.png");
+		}
+		String key = extractKeyFromS3Url(s3Url);
+		return generateGetPresignedUrl(key);
+	}
+
+	private String generateGetPresignedUrl(String imageKey) {
+		GetObjectRequest getObjectRequest = GetObjectRequest.builder()
+				.bucket(BUCKET_NAME)
+				.key(imageKey)
+				.build();
+
+		GetObjectPresignRequest presignRequest = GetObjectPresignRequest.builder()
+				.signatureDuration(Duration.ofHours(24))
+				.getObjectRequest(getObjectRequest)
+				.build();
+
+		return s3Presigner.presignGetObject(presignRequest).url().toString();
+	}
+
+
+	private String extractKeyFromS3Url(String s3Url) {
+		// https://group2-englishstudy.s3.amazonaws.com/profile/user123/img.png
+		// → profile/user123/img.png
+		String prefix = String.format("https://%s.s3.amazonaws.com/", BUCKET_NAME);
+		if (s3Url.startsWith(prefix)) {
+			return s3Url.substring(prefix.length());
+		}
+		return s3Url;
 	}
 
 	/**