导入更新

backend-java/src/main/java/com/pharmacopoeia/controller/ChatController.java

@@ -7,6 +7,7 @@ import com.pharmacopoeia.dto.ImageChatRequest;
 import com.pharmacopoeia.dto.MultimodalChatRequest;
 import com.pharmacopoeia.service.*;
 import jakarta.servlet.http.HttpServletRequest;
+import org.springframework.http.MediaType;
 import org.springframework.http.ResponseEntity;
 import org.springframework.http.codec.ServerSentEvent;
 import org.springframework.security.core.context.SecurityContextHolder;