[英]How to dynamically push-update pages in vaadin?
I have a working application with Vaadin
and Spring (+Security)
. 我有一个与Vaadin
和Spring (+Security)
一起工作的应用程序。 I'm now trying to dynamically push updates to the client interfaces using vaadin-push
. 我现在正尝试使用vaadin-push
将更新动态推送到客户端接口。
I want to create a "view" that is the same for all clients. 我想创建一个对所有客户端都相同的“视图”。 The view should get a counter incremented dynamically by push. 该视图应获得通过推送动态递增的计数器。 So, while the clients show the page, the counter updates itself (or in my example: appends multiple label components to the page). 因此,当客户端显示页面时,计数器会自动更新(或在我的示例中:将多个标签组件添加到页面)。 Every client should see the same value. 每个客户应该看到相同的价值。
But I don't see the changes pushed to the webpage. 但我看不到更改已推送到网页。 Why? 为什么?
//the static controller the dynamically changes content
@Controller
public class ViewPresenter {
private static int counter = 0;
@Autowired
private void StaticView view;
@Scheduled(fixedRate = 1000)
public void refresh() {
//push the content change periodically to frontend
view.getUI().access(new Runnable() {
@Override
public void run() {
view.addComponent(new Label("refresh: " + counter++);
Sysout("update executed: " + counter); //OK, is printed
}
});
}
}
//the static test component that gets a new label added on every content change
@VaadinComponent
public class StaticView extends CssLayout {
//this is the view that every client should see
}
//the secured admin view
@VaadinView(name = "/secured")
@Scope("ui")
@Secured("user")
public class SecuredView extends VerticalLayout implements View {
@Autowired
private StaticView staticView;
@Override
public void enter(ViewChangeEvent event) {
addComponent(staticView);
}
}
//enable push
@Configuration
@Push
public class AppConfig {
}
@VaadinUI
@PreserveOnRefresh
public class ApplicationUI extends UI {
}
I can see the changes on the client side only if I manually refresh the webpage. 仅当我手动刷新网页时,才能在客户端看到更改。 But the content itself does not change automatically. 但是内容本身不会自动更改。
Maybe @Push
has to be placed on the UI
class? 也许@Push
必须放在UI
类上? But in this case I'd get the following error: 但是在这种情况下,我会得到以下错误:
java.lang.IllegalStateException: Cannot suspend a response longer than the session timeout. java.lang.IllegalStateException:无法暂停响应的时间超过会话超时。 Increase the value of session-timeout in web.xml at org.atmosphere.cpr.AtmosphereResourceImpl.suspend(AtmosphereResourceImpl.java:314) at org.atmosphere.cpr.AtmosphereResourceImpl.suspend(AtmosphereResourceImpl.java:292) at com.vaadin.server.communication.PushHandler$2.run(PushHandler.java:129) at com.vaadin.server.communication.PushHandler.callWithUi(PushHandler.java:242) at com.vaadin.server.communication.PushHandler.access$200(PushHandler.java:55) at com.vaadin.server.communication.PushHandler$1.onRequest(PushHandler.java:73) 在com.vaadin的org.atmosphere.cpr.AtmosphereResourceImpl.suspend(AtmosphereResourceImpl.java:292)的org.atmosphere.cpr.AtmosphereResourceImpl.suspend(AtmosphereResourceImpl.java:314)处的web.xml中增加会话超时值。在com.vaadin.server.communication.PushHandler.callWithUi(PushHandler.java:242)处的server.communication.PushHandler $ 2.run(PushHandler.java:129)在com.vaadin.server.communication.PushHandler.access $ 200(PushHandler。 java:55)com.vaadin.server.communication.PushHandler $ 1.onRequest(PushHandler.java:73)
Solution based on https://github.com/peholmst/vaadin4spring/issues/51#issuecomment-46875255 : 基于https://github.com/peholmst/vaadin4spring/issues/51#issuecomment-46875255的解决方案:
server.sessionTimeout=30
with @Push(transport = Transport.LONG_POLLING)
@Push(transport = Transport.LONG_POLLING)
server.sessionTimeout=30
@Push(transport = Transport.LONG_POLLING)
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