调整过敏解答

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

@@ -179,6 +179,13 @@ public class ChatController {
 
         Sinks.Many<ServerSentEvent<String>> sink = Sinks.many().unicast().onBackpressureBuffer();
 
+        // 校验图片数据
+        if (request.getImageBase64() == null || request.getImageBase64().isBlank()) {
+            sink.tryEmitNext(ServerSentEvent.<String>builder().event("status").data("图片数据为空，请重新上传").build());
+            sink.tryEmitComplete();
+            return sink.asFlux();
+        }
+
         try {
             sink.tryEmitNext(ServerSentEvent.<String>builder().event("status").data("正在分析图片（OCR 文字识别）...").build());