Question

我目前正在使用MVP模式使用Vaadin Flow（v11.0.0）和Spring Boot（v2.0.4）开发应用程序。只要仅在单个选项卡中打开该应用程序即可正常运行。重新加载时会刷新整个页面，这完全可以。同时在第二个标签页或窗口中打开它（无论是否隐身都没关系）可以正常工作。但是，当我在一个窗口中单击某个内容，然后在另一个窗口中单击时，会发生以下错误：

java.lang.IllegalStateException: Cannot access state in VaadinSession or UI without locking the session.
at com.vaadin.flow.server.VaadinSession.checkHasLock(VaadinSession.java:515) ~[flow-server-1.0.5.jar:na]
at com.vaadin.flow.server.VaadinSession.checkHasLock(VaadinSession.java:529) ~[flow-server-1.0.5.jar:na]
at com.vaadin.flow.internal.StateTree.checkHasLock(StateTree.java:390) ~[flow-server-1.0.5.jar:na]
at com.vaadin.flow.internal.StateTree.markAsDirty(StateTree.java:258) ~[flow-server-1.0.5.jar:na]
at com.vaadin.flow.internal.StateNode.markAsDirty(StateNode.java:326) ~[flow-server-1.0.5.jar:na]
at com.vaadin.flow.internal.nodefeature.NodeValue.markAsDirty(NodeValue.java:85) ~[flow-server-1.0.5.jar:na]
at com.vaadin.flow.internal.nodefeature.NodeValue.setValue(NodeValue.java:78) ~[flow-server-1.0.5.jar:na]
at com.vaadin.flow.internal.nodefeature.TextNodeMap.setText(TextNodeMap.java:52) ~[flow-server-1.0.5.jar:na]

我只有一个视图（因此也是演示者），我会这样注释：

@Route(value = LogAnalysis.route)
@PageTitle(LogAnalysis.name)
class LogAnalysisView(val presenter: LogAnalysis.ViewPresenter) : VerticalLayout(), LogAnalysis.View, BeforeEnterObserver { ... }

@Component
@UIScope
@VaadinSessionScope
class LogAnalysisPresenter(val service: LogAnalysis.Service) : LogAnalysis.ServicePresenter, LogAnalysis.ViewPresenter { ... }

Answer 1

我也通过在服务（模型）中添加@UIScope注释来解决了这个问题。

我认为该服务可以是单例的，因为它只是从数据库中获取和准备数据，但是该服务拥有对演示者的引用，该引用在每次创建新Session时都会被覆盖。

Vaadin Flow＆Spring Boot：在多个标签/窗口中打开时出错

1 个答案: