GWT-Platform :在tomcat/jboss上部署应用程序时，浏览器刷新时不会调用onReveal()方法

Question

在我的一个GWT应用程序中，我遇到了一个奇怪的问题，当我在eclipse GWT插件中配置的jetty中运行应用程序并点击浏览器刷新时，当前页面被成功加载(placeManager.getCurrentPlaceRequest())，但是当应用程序war被部署在tomcat/jboss中时，执行在当前位置请求的呈现者的onBind()方法之后停止，并且没有显示页面。

在处理刷新的过程中，该Presenter的GateKeeper的first time canReveal()方法返回false，并且在一次服务器调用之后，我再次显示current place，这导致canReveal()方法返回true，但是presenter仍然未显示。所以，在这里我怀疑有些事情是棘手的！

有关于这种行为的任何提示吗？

以下是实现的LoggedInGatekeeper的代码片段，它起到了关键作用：

public class LoggedInGatekeeper implements Gatekeeper {

private final EventBus eventBus;

private final DispatchAsync dispatcher;

private final PlaceManager placeManager;

private CurrentUser currentUser;

private boolean isUserLoggedOut;

private String lastPageAccessed;

@Inject
public LoggedInGatekeeper(final EventBus eventBus, final DispatchAsync dispatcher, final PlaceManager placeManager)
{
    this.eventBus = eventBus;

    this.dispatcher = dispatcher;

    this.placeManager = placeManager;

    this.eventBus.addHandler(LoginAuthenticatedEvent.getType(), new LoginAuthenticatedEventHandler()
    {
        @Override
        public void onLogin(LoginAuthenticatedEvent event)
        {
            currentUser = event.getCurrentUser();
            isUserLoggedOut = false;
        }
    });

    this.eventBus.addHandler(LogoutUserEvent.getType(), new LogoutUserEventHandler()
    {
        @Override
        public void onLogoutUser(LogoutUserEvent event)
        {
            SessionFactory.removeCookie(Constants.LAST_PAGE_ACCESSED);
            currentUser = null;
            isUserLoggedOut = true;
        }
    });
}

@Override
public boolean canReveal()
{
    Log.info("Browser fetched session cookie : " + Cookies.getCookie(Constants.JSESSION_COOKIE_KEY));

    if (Cookies.getCookie(Constants.JSESSION_COOKIE_KEY) == null)
    {
        SC.say("Your session is expired. Please login again");
        NavigateToLoginEvent.fire(eventBus);
        return false;
    }

    if (currentUser != null && !isUserLoggedOut)
    {

        lastPageAccessed = placeManager.getCurrentPlaceRequest().getNameToken();
        Log.info("canReveal() 1 : " + lastPageAccessed);
        SessionFactory.addCookie(Constants.LAST_PAGE_ACCESSED, lastPageAccessed);
        return currentUser.isLoggedIn();
    }
    else if (isUserLoggedOut)
    {
        Log.info("canReveal() 2 : User is logged out");
        NavigateToLoginEvent.fire(eventBus);
        return false;
    }
    else
    {
        Log.info("canReveal() 3 : Check on server for logged in user");
        dispatcher.execute(new FetchLoggedInUserAction(), new FetchLoggedInUserAsyncCallback());
        return true;
    }
}

class FetchLoggedInUserAsyncCallback extends MessageAsyncCallback<FetchLoggedInUserResult>
{
    /**
     * 
     */
    public FetchLoggedInUserAsyncCallback()
    {
        super("Loading...");
    }

    @Override
    public void doOnFailure(Throwable caught)
    {
        NavigateToLoginEvent.fire(eventBus);
    }

    @SuppressWarnings("unchecked")
    @Override
    public void doOnSuccess(FetchLoggedInUserResult result)
    {
        if (result == null)
        {
            Log.info("doOnSuccess() 1 : LoggedInUser not found on server");
            NavigateToLoginEvent.fire(eventBus);
        }
        else
        {
            Log.info("doOnSuccess() 2 : LoggedInUser found on server");
            if (result.getLoggedInUser() != null)
            {

                currentUser = new CurrentUser();
                currentUser.setMerchantConsoleUser(result.getLoggedInUser());

                SessionFactory.getClientSessionInstance().put(SessionKeys.LOGGED_IN_USER, result.getLoggedInUser());

                PlaceRequest currentPlaceRequest = placeManager.getCurrentPlaceRequest();

                Log.info("doOnSuccess() 3 : " + currentPlaceRequest.getNameToken());

                if (currentPlaceRequest != null)
                {   
                    placeManager.revealPlace(currentPlaceRequest);
                }
            }
            else
            {
                NavigateToLoginEvent.fire(eventBus);
            }
        }
    }
}

}

​

提前谢谢。

Answer 1

谜团揭开，在onBind()方法中添加了以下代码，浏览器刷新开始在所有环境中按预期工作。这看起来像是框架的模糊行为，当时GateKeeper试图从服务器获取数据，不知何故，presenter的可见性被设置为false，同样的想法导致我写了以下代码，它起作用了，希望GWT-P的人可以看看这篇文章，想出适当的方法来处理这种情况：

/**
     * This piece of code takes care of revealing page on browser refresh event.
     * On browser refresh somehow visibility of page is set to false, so, we need to manually fire the reveal content event.
     */
    if(this.getProxy().canReveal() == true && !this.isVisible()){
                revealInParent();
    }