Enthuware

Code: Select all

@WebListener
public class MyListener implements AsyncListener {
    
     ... 
    public void onStartAsync(AsyncEvent event){
        
        System.out.println("Async Listener on start");
    }
     ...
}

Code: Select all

@WebServlet(urlPatterns="/foo/*",
            name = "NullServlet",
            asyncSupported = true)
public class NullServlet extends HttpServlet {
    public void doGet(HttpServletRequest req, HttpServletResponse resp){
        MyListener myAsyncListener = new MyListener();
        req.setAttribute("org.apache.catalina.ASYNC_SUPPORTED", true);
        final AsyncContext ac = req.startAsync();
        ac.addListener(myAsyncListener);
        
        ac.start(new Runnable(){
            public void run(){
                System.out.println(" I am async thread.");
             }
        });
        //try to start a new async process, 
        //but the listener's onStartAsync method is not called.
        ac.start(new Runnable(){
            public void run(){
                System.out.println(" I am async thread 1 .");
              
            }
        });
        
       
    }
}

Code: Select all

AsyncContext ac=request.startAsync(); // line 1
//onStartAsync is not called here by the container
ac.addListener(myAsyncListener);  //line 2
//onStartAsync is not called here as the async process has already started.