feat: add specific handler for CameraDeviceErrorException

Author: kCn3333

src/main/java/com/kcn/hikvisionmanager/client/HttpDownloadClient.java

@@ -2,6 +2,7 @@
 
 import com.kcn.hikvisionmanager.config.CameraConfig;
 import com.kcn.hikvisionmanager.events.model.CameraRestartInitiatedEvent;
+import com.kcn.hikvisionmanager.exception.CameraDeviceErrorException;
 import com.kcn.hikvisionmanager.exception.CameraRequestException;
 import com.kcn.hikvisionmanager.exception.CameraUnauthorizedException;
 import com.kcn.hikvisionmanager.service.ProgressListener;
@@ -117,13 +118,24 @@ public void executeDownloadStream(
         try {
             httpClient.execute(httpGet, response -> {
                 int statusCode = response.getCode();
+
                 log.debug("Download response status: {}", statusCode);
 
                 // Handle authentication errors
                 if (statusCode == 401 || statusCode == 403) {
                     throw new CameraUnauthorizedException(
                             "Unauthorized download request to camera " + cameraConfig.getIp());
                 }
+                // Handle Hikvision device error
+                if (statusCode == 500) {
+                    String errorBody = EntityUtils.toString(response.getEntity());
+                    if(errorBody.contains("<subStatusCode>deviceError</subStatusCode>")) {
+                        throw new CameraDeviceErrorException(
+                                "Camera returned DEVICE ERROR. The device is overloaded or internal buffer failed."
+                        );
+                    }
+                    throw new CameraRequestException("500 Internal Error: " + errorBody);
+                }
 
                 // Handle HTTP errors
                 if (statusCode >= 400) {

src/main/java/com/kcn/hikvisionmanager/exception/CameraDeviceErrorException.java

@@ -0,0 +1,7 @@
+package com.kcn.hikvisionmanager.exception;
+
+public class CameraDeviceErrorException extends CameraRequestException {
+    public CameraDeviceErrorException(String message) {
+        super(message);
+    }
+}

src/main/java/com/kcn/hikvisionmanager/exception/GlobalExceptionHandler.java

@@ -81,6 +81,21 @@ public ResponseEntity<ApiErrorResponse> handleUnauthorized(CameraUnauthorizedExc
         return ResponseEntity.status(HttpStatus.UNAUTHORIZED).body(response);
     }
 
+    @ExceptionHandler(CameraDeviceErrorException.class)
+    public ResponseEntity<ApiErrorResponse> handleCameraDeviceError(
+            CameraDeviceErrorException ex, HttpServletRequest request) {
+
+        // Using 503 Service Unavailable because the device is likely overloaded/busy
+        ApiErrorResponse response = ApiErrorResponse.of(
+                HttpStatus.SERVICE_UNAVAILABLE,
+                "Camera device error: " + ex.getMessage(),
+                request.getRequestURI()
+        );
+
+        log.warn("🔥 Camera internal device error on {}: {}", request.getRequestURI(), ex.getMessage());
+        return ResponseEntity.status(HttpStatus.SERVICE_UNAVAILABLE).body(response);
+    }
+
     @ExceptionHandler(CameraOfflineException.class)
     public ResponseEntity<ApiErrorResponse> handleCameraOfflineException(
             CameraOfflineException ex, HttpServletRequest request) {