[Backend] fix: 에러 예외처리 수정 및 SSE CORS 설정

backend/src/main/java/com/example/backend/analysis/controller/CaseStatsController.java

@@ -7,7 +7,6 @@
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 
-import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 
@@ -23,10 +22,6 @@ public class CaseStatsController {
     public ResponseEntity<?> getOverview(HttpSession session) {
         // 결과가 없으면 404, 있으면 200
         CaseStatsOverviewResponse response = caseStatsService.getOverview(session);
-        if (response == null) {
-            return ResponseEntity.status(404)
-                    .body(Collections.singletonMap("message", "개요 정보가 없습니다."));
-        }
         return ResponseEntity.ok(response);
     }
 
@@ -36,10 +31,6 @@ public ResponseEntity<?> getHourlyCaseStats(@RequestParam("date") String date,
                                                 @RequestParam(value = "category", required = false) String category,
                                                 HttpSession session) {
         List<HourlyCaseStatsResponse> stats = caseStatsService.getHourlyCaseStats(date, category, session);
-        if (stats.isEmpty()) {
-            return ResponseEntity.status(404)
-                    .body(Collections.singletonMap("message", "시간대별 사건 정보가 없습니다."));
-        }
         return ResponseEntity.ok(stats);
     }
 

backend/src/main/java/com/example/backend/analysis/service/CaseStatsService.java

@@ -56,7 +56,7 @@ public CaseStatsOverviewResponse getOverview(HttpSession session) {
 
         // 최근 한 달간 데이터를 기준으로 사건 건수가 가장 많은 CCTV 주소 조회
         String patrolRegionAddress = statsOverviewRepository.findAddressWithMostIncidentsLastMonth(officeId)
-                .orElse("정보 없음");
+                .orElse("해당 지역에 순찰 강화 필요 구역이 없습니다.");
 
         return CaseStatsOverviewResponse.fromEntity(stats, patrolRegionAddress);
     }

backend/src/main/java/com/example/backend/common/GlobalExceptionHandler.java

@@ -1,21 +1,32 @@
 package com.example.backend.common;
 
-import org.springframework.web.bind.annotation.ControllerAdvice;
-
 import jakarta.persistence.EntityNotFoundException;
+import jakarta.servlet.http.HttpServletResponse;
+import lombok.extern.slf4j.Slf4j;
 import org.springframework.http.HttpStatus;
+import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.ControllerAdvice;
 import org.springframework.web.bind.annotation.ExceptionHandler;
 
+import java.io.IOException;
 import java.util.Collections;
 import java.util.NoSuchElementException;
 
+@Slf4j
 @ControllerAdvice
 public class GlobalExceptionHandler {
 
+    // SSE 연결 종료 (브라우저에서 탭 닫거나, 연결 끊긴 경우)
+    @ExceptionHandler(IOException.class)
+    public void handleIOException(IOException e) {
+        log.warn("SSE 연결 종료: {}", e.getMessage());
+    }
+
     @ExceptionHandler(IllegalStateException.class)
     public ResponseEntity<?> handleIllegalStateException(IllegalStateException e) {
-        if (e.getMessage().contains("로그인이 필요합니다.")) {
+        log.warn("IllegalStateException: {}", e.getMessage());
+        if (e.getMessage().contains("로그인이 필요")) {
             return ResponseEntity.status(HttpStatus.UNAUTHORIZED)
                     .body(Collections.singletonMap("message", e.getMessage()));
         }
@@ -36,8 +47,19 @@ public ResponseEntity<?> handleEntityNotFoundException(EntityNotFoundException e
     }
 
     @ExceptionHandler(Exception.class)
-    public ResponseEntity<?> handleGenericException(Exception e) {
-        return ResponseEntity.status(HttpStatus.INTERNAL_SERVER_ERROR)
-                .body(Collections.singletonMap("message", e.getMessage()));
+    public void handleGenericException(Exception e, HttpServletResponse response) throws IOException {
+        log.error("Unexpected error: ", e);
+        if ("text/event-stream".equals(response.getContentType())) {
+            // SSE 통신 도중 에러 → event-stream 포맷으로 전달
+            response.getWriter().write("event: error\n");
+            response.getWriter().write("data: " + e.getMessage() + "\n\n");
+            response.getWriter().flush();
+        } else {
+            // 일반 요청 → JSON 에러 응답
+            response.setStatus(HttpStatus.INTERNAL_SERVER_ERROR.value());
+            response.setContentType(MediaType.APPLICATION_JSON_VALUE);
+            response.getWriter().write("{\"message\": \"" + e.getMessage() + "\"}");
+            response.getWriter().flush();
+        }
     }
 }

backend/src/main/java/com/example/backend/config/CorsConfig.java

@@ -16,8 +16,8 @@ public void addCorsMappings(CorsRegistry corsRegistry) {
         corsRegistry.addMapping("/**")
                 .allowedOrigins(allowedOrigins)
                 .allowedMethods("GET", "POST", "PUT", "DELETE", "OPTIONS", "HEAD")
-                .allowedHeaders("Authorization", "Content-Type")
-                .exposedHeaders("Authorization")
+                .allowedHeaders("Authorization", "Content-Type", "Last-Event-ID")
+                .exposedHeaders("Authorization", "Content-Type", "Cache-Control", "Last-Event-ID")
                 .allowCredentials(true);
     }
 }

backend/src/main/java/com/example/backend/config/SecurityConfig.java

@@ -1,8 +1,5 @@
 package com.example.backend.config;
 
-import java.util.Arrays;
-import java.util.List;
-
 import lombok.RequiredArgsConstructor;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.context.annotation.Bean;
@@ -15,6 +12,9 @@
 import org.springframework.web.cors.CorsConfigurationSource;
 import org.springframework.web.cors.UrlBasedCorsConfigurationSource;
 
+import java.util.Arrays;
+import java.util.List;
+
 @Configuration
 @EnableWebSecurity
 @RequiredArgsConstructor
@@ -28,22 +28,21 @@ public SecurityFilterChain filterChain(HttpSecurity httpSecurity) throws Excepti
         return httpSecurity
                 .csrf(AbstractHttpConfigurer::disable)
                 .httpBasic(AbstractHttpConfigurer::disable)
-                // CORS 설정을 수동으로 추가
                 .cors(cors -> cors.configurationSource(corsConfigurationSource()))
                 .build();
     }
 
-    // CORS 설정을 위한 Bean 정의
     @Bean
     public CorsConfigurationSource corsConfigurationSource() {
         CorsConfiguration configuration = new CorsConfiguration();
         configuration.setAllowedOrigins(List.of(allowedOrigins)); // 프론트엔드 도메인
         configuration.setAllowedMethods(Arrays.asList("GET", "POST", "PUT", "DELETE", "OPTIONS", "HEAD")); // 허용할 HTTP 메서드
-        configuration.setAllowedHeaders(Arrays.asList("Authorization", "Content-Type")); // 허용할 헤더
-        configuration.setExposedHeaders(List.of("Authorization")); // 응답에서 노출할 헤더
+        configuration.setAllowedHeaders(Arrays.asList("Authorization", "Content-Type", "Last-Event-ID")); // 허용할 헤더
+        configuration.setExposedHeaders(Arrays.asList("Authorization", "Content-Type", "Cache-Control", "Last-Event-ID")); // 응답에서 노출할 헤더
         configuration.setAllowCredentials(true); // 자격 증명 포함 요청 허용
+
         UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
         source.registerCorsConfiguration("/**", configuration); // 모든 경로에 대해 CORS 설정 적용
         return source;
     }
-}
+}

backend/src/main/java/com/example/backend/dashboard/controller/CaseDetectController.java

@@ -4,7 +4,9 @@
 import com.example.backend.dashboard.dto.CaseDetectResponse;
 import com.example.backend.dashboard.service.CaseDetectService;
 import com.example.backend.dashboard.service.SseEmitterService;
+import jakarta.servlet.http.HttpServletResponse;
 import lombok.RequiredArgsConstructor;
+import org.springframework.beans.factory.annotation.Value;
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 import org.springframework.web.servlet.mvc.method.annotation.SseEmitter;
@@ -17,6 +19,9 @@ public class CaseDetectController {
     private final CaseDetectService caseDetectService;
     private final SseEmitterService sseEmitterService;
 
+    @Value("${cors.allowed-origins}")
+    private String allowedOrigin;
+
     @PostMapping("/detect")
     public ResponseEntity<?> detectAlarm(@RequestBody CaseDetectRequest request) {
         CaseDetectResponse response = caseDetectService.saveCase(request);
@@ -25,7 +30,12 @@ public ResponseEntity<?> detectAlarm(@RequestBody CaseDetectRequest request) {
     }
 
     @GetMapping("/subscribe")
-    public SseEmitter subscribe() {
+    public SseEmitter subscribe(HttpServletResponse response) {
+        response.setHeader("Access-Control-Allow-Origin", allowedOrigin);
+        response.setHeader("Access-Control-Allow-Credentials", "true");
+        response.setHeader("Cache-Control", "no-cache");
+        response.setHeader("Connection", "keep-alive");
+
         return sseEmitterService.createEmitter();
     }
 

backend/src/main/java/com/example/backend/dashboard/controller/DashboardController.java

@@ -7,7 +7,6 @@
 import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
 
-import java.util.Collections;
 import java.util.List;
 import java.util.Map;
 
@@ -22,10 +21,6 @@ public class DashboardController {
     @GetMapping("")
     public ResponseEntity<?> getCases(HttpSession session) {
         List<DashboardResponse> cases = dashboardService.getCases(session);
-        if (cases.isEmpty()) {
-            return ResponseEntity.status(404)
-                    .body(Collections.singletonMap("message", "사건이 없습니다."));
-        }
         return ResponseEntity.ok(cases);
     }
 

backend/src/main/java/com/example/backend/dashboard/service/DashboardService.java

@@ -66,6 +66,10 @@ public List<DashboardResponse> getCases(HttpSession session) {
         );
         List<CaseEntity> cases = dashboardRepository.findAllByOfficeIdAndStateInOrderById(officeId, targetStates);
 
+        if (cases.isEmpty()) {
+            throw new NoSuchElementException("미확인, 확인 또는 출동 중인 사건이 없습니다.");
+        }
+
         return cases.stream()
                 .map(DashboardResponse::fromEntity)
                 .collect(Collectors.toList());
@@ -80,6 +84,11 @@ public Map<String, String> getCaseVideo(int id, HttpSession session) {
             throw new EntityNotFoundException("해당 사건에 대한 영상이 없습니다.");
         }
 
+        if (caseEntity.getState() == CaseEntity.CaseState.미확인) {
+            caseEntity.setState(CaseEntity.CaseState.확인);
+            dashboardRepository.save(caseEntity);
+        }
+
         return Collections.singletonMap("video", videoUrl);
     }