I make a crud project of servlet + JSP, and start Tomcat with an error:
org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/oa3]]
It was found that the path was not added ‘/’
//@WebServlet("dept/list")
//Add slash!
@WebServlet("/dept/list")
public class DeptServlet extends HttpServlet {