Because usually lazy so afraid to forget to record it.
I use a tool or idea, is not inherited HttpServlet class practicing handwriting at the beginning of spring when the core code of ioc and di:
Incidentally, the record about ctrl + o shortcut keys: the display method of the current class
Resolve as follows:
One: Open the idea: click on the file -> select Project Structure
two:
Find your local directory after tomcat> - - Select Libraries -> select the + -> Add java> lib select the following servlet-api.jar this file and then save it
