修复bug

app/src/main/java/com/bgycc/smartcanteen/server/websocket/MainWebSocket.java

@@ -169,13 +169,15 @@ public class MainWebSocket extends WebSocketClient {
 
             Request request = new Request();
             request.action = action;
-            request.response = callback;
             request.params = new JSONObject();
             request.params.put(FieldEnum.equipmentId.name(), sDeviceSN);
             request.params.put(FieldEnum.serialNumber.name(), mSessionId);
             request.params.put(FieldEnum.action.name(), action);
             request.params.put(FieldEnum.data.name(), data);
-            mRequestList.put(mSessionId, request);
+            if (callback != null) {
+                request.response = callback;
+                mRequestList.put(mSessionId, request);
+            }
 
             String msg = request.params.toString();
             LogUtil.i(TAG, String.format("send: %s", msg));