Record a garbled code during servlet learning

When learning Servlet Single watch maker CRUD When , Encountered a strange garbled code , Because I have checked all the previous posts , I still haven't found out what the problem is , His phenomenon is very strange , Other garbled codes may be a bunch of strange symbols , But this garbled code is servlet After forwarding the request between, the Chinese became question mark , As shown in the figure below ：

After checking the code, it is found that , It's actually a line of inconspicuous ruoyuowu 、 It's caused by nonexistent code , It is ：

PrintWriter out = response.getWriter();

Comments will return to normal , I don't understand why this happened , I don't know what caused it , Hope to know the big guys to answer oh ！