Merge pull request #1816 from octo-patch/fix/issue-1808-1788-null-content-sse-stream

fix: handle null content in SSE stream chunks for REST and Zhipu AI

Author: Chat2DB-Pro

chat2db-server/chat2db-server-web/chat2db-server-web-api/src/main/java/ai/chat2db/server/web/api/controller/ai/rest/listener/RestAIEventSourceListener.java

@@ -64,6 +64,11 @@ public void onEvent(EventSource eventSource, String id, String type, String data
             String text = chatCompletions.getChoices().get(0).getDelta()==null?
                     chatCompletions.getChoices().get(0).getText()
                     :chatCompletions.getChoices().get(0).getDelta().getContent();
+            // Local LLMs (e.g. llama.cpp) may return null content in the first SSE chunk
+            // (only role is present). Treat null as empty string to avoid NullPointerException.
+            if (text == null) {
+                text = "";
+            }
             message.setContent(text);
             sseEmitter.send(SseEmitter.event()
                 .id(id)

chat2db-server/chat2db-server-web/chat2db-server-web-api/src/main/java/ai/chat2db/server/web/api/controller/ai/zhipu/listener/ZhipuChatAIEventSourceListener.java

@@ -62,6 +62,11 @@ public void onEvent(EventSource eventSource, String id, String type, @NotNull St
         String text = chatCompletions.getChoices().get(0).getDelta()==null?
                 chatCompletions.getChoices().get(0).getText()
                 :chatCompletions.getChoices().get(0).getDelta().getContent();
+        // The first SSE chunk may carry only "role" with null "content".
+        // Guard against NullPointerException from Message.setContent().
+        if (text == null) {
+            text = "";
+        }
 
         Message message = new Message();
         message.setContent(text);