HttpSessionListener.sessionCreated（）未被调用 [英] HttpSessionListener.sessionCreated() not being called

问题描述

我有一个非常简单的Servlet和一个非常简单的HttpSessionListener：

I have a very simple Servlet and a very simple HttpSessionListener:

@WebServlet("/HelloWorld")
public class HelloWorld extends HttpServlet {
    private static final long serialVersionUID = 1L;


    @Override
    public void init(ServletConfig config) throws ServletException {
        super.init(config);
        getServletContext().setAttribute("applicationHits", new AtomicInteger(0));  
    }


    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        System.out.println("get");

        ((AtomicInteger) request.getServletContext().getAttribute("applicationHits")).incrementAndGet();
        ((AtomicInteger) request.getSession(true).getAttribute("sessionHits")).incrementAndGet();
        request.setAttribute("requestHits", 0);

        getServletContext().getRequestDispatcher("/view/HelloWorld.jsp").forward(request, response);
    }

}

 

@WebListener
public class SessionListener implements HttpSessionListener {

    public SessionListener() {
    }

    public void sessionCreated(HttpSessionEvent arg0)  {
        System.out.println("session listener");
        arg0.getSession().setAttribute("sessionHits", new AtomicInteger(0));
    }

    public void sessionDestroyed(HttpSessionEvent arg0)  { 
    }

}

我的 HttpSessionListener.sessionCreated（）方法永远不会被调用（没有日志输出），我最终得到一个<我正在调用getSession（）

My HttpSessionListener.sessionCreated() method is never called (no log output), and I end up getting a NullPointerException on the line where I'm calling getSession()

((AtomicInteger) request.getSession(true).getAttribute("sessionHits")).incrementAndGet();
        request.setAttribute("requestHits", 0);

我试过调用 getSession（）而不用 true 以及同样的问题。

I tried calling getSession() without true as well, but same problem.

我不明白 - 是不是 @WebListener 注释足以调用我的监听器？ Eclipse甚至在部署描述符/监听器下将其显示为侦听器。

I don't get it - isn't the @WebListener annotation enough to invoke my listener? Eclipse even displays it as a listener under Deployment Descriptor/Listeners.

推荐答案

原来这是一个愚蠢的Eclipse问题......

Turns out it was one of those stupid Eclipse issues...

项目 - >清理......然后重启Tomcat就行了。

Project->Clean... and restarting Tomcat did the trick.

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