GetServletContext在扩展HttpServlet的类中返回null

Question

So I have a class that extends HttpServlet and I was trying to access variables set in different class that has implemented ServletContextListener.

However the following line of code in the class that extends HttpServlet is giving me the NullPOinterException:

SomeObject x =  getServletContext().getAttribute("x");

I don't understand why this is happening. Any ideas?

Answer 1

可能是您在Servlet类中重写了init（ServletConfig cfg）方法，并且没有调用super.init（cfg）进行标准设置，从而导致上下文为空。