java - 错误: Not detached model found

Question

我在使用 Wicket 6.19 时遇到以下错误:

    Caused by: org.apache.wicket.core.util.objects.checker.CheckingObjectOutputStream$ObjectCheckException: Not detached model found!
A problem occurred while checking object with type: com.test.web.components.CurrentUserModel
Field hierarchy is:
   [class=com.test.web.base.pages.HomePage, path=0]
    private java.lang.Object org.apache.wicket.MarkupContainer.children [class=[Ljava.lang.Object;]
      java.lang.Object org.apache.wicket.Component.data[1] [class=com.test.web.HeaderPanel, path=0:headerPanel]
        private java.lang.Object org.apache.wicket.MarkupContainer.children [class=[Ljava.lang.Object;]
          private java.lang.String org.apache.wicket.markup.html.image.resource.LocalizedImageResource.variation[2] [class=com.test.web.LoginStatusPanel, path=0:headerPanel:loginStatusPanel]
            java.lang.Object org.apache.wicket.Component.data [class=com.test.web.components.CurrentUserModel] <----- field that is causing the problem

代码:

@RequireHttps
public class HomePage extends WebPage {
    private HeaderPanel headerPanel;
    private LoginStatusPanel loginStatusPanel;
    private MenuPanel menuPanel;

    public HomePage(String id) {
        super();
        initialize();
    }

    public HomePage(String id, PageParameters parameters) {
        super(parameters);
        initialize();
    }

    @Override
    protected void onInitialize() {
        Request request = RequestCycle.get().getRequest();
        if (request instanceof ServletWebRequest)
        {
            ServletWebRequest wr = (ServletWebRequest) request;
            HttpSession session = wr.getContainerRequest().getSession();
            if (session != null) {
            }
        }
        super.onInitialize();
    }

    public String getApplicationId(){
        return applicationId;
    }

    private void initialize() {
        add(headerPanel = new HeaderPanel("headerPanel"));
        headerPanel.add(loginStatusPanel = new LoginStatusPanel("loginStatusPanel"));
        headerPanel.add(menuPanel = new MenuPanel("menuPanel"));
    }
}

public class HeaderPanel extends Panel {
    private Label headerTitleLbl;

    public HeaderPanel(String id) {
        super(id);
        add(headerTitleLbl=new Label("headerTitle", WebApplication.getAppTitle()));
        headerTitleLbl.setOutputMarkupId(true);
    }
}

public class LoginStatusPanel extends Panel {

    public LoginStatusPanel(String id) {
        super(id, new CurrentUserModel()); // Line 1
    }

    protected void onInitialize() {
        IModel<Authentication> authModel = (IModel<Authentication>) getDefaultModel();
        final Authentication auth = authModel.getObject();

        if (auth != null && auth.isAuthenticated() && !(auth instanceof AnonymousAuthenticationToken))
        {
            Fragment fragment = new Fragment("frag", "loggedInFragment", this);
            Label status;
            fragment.add(status = new Label("status", "Logged in as "));
            fragment.add(new Label("userId", new PropertyModel<String>(authModel, "name")));
            add(fragment);
        }
        else
        {
            Fragment fragment = new Fragment("frag", "loggedOutFragment", this);
            fragment.add(new Label("status", "Logged out"));
            fragment.add(new ExternalLink("login", "/LoginPage", "Log In"));
            add(fragment);
        }
        super.onInitialize();
    }
}

public class MenuPanel extends Panel {
    public MenuPanel(String id) {
        super(id);
        add(new MenuPanel("menu", WebApplication.getMenuList()));
    }
}

public class CurrentUserModel extends LoadableDetachableModel<Authentication> {
    protected Authentication load() {
        return SecurityContextHolder.getContext().getAuthentication();
    }
}

注意:如果我使用以下内容更新注释中标记为“第 1 行”的代码:

super(id, new Model(SecurityContextHolder.getContext().getAuthentication()));

错误没有显示，这可能是因为它不是 LoadableDetachableModel。

是否可以将 LoadableDetachableModel 的实例传递给 Component 类构造函数？

对于以下代码，我也遇到相同的错误:

tree = new NestedTree<TreeItem>("tree", provider, state);

其中状态是以下类的实例:

private class TreeItemExpansionModel extends LoadableDetachableModel<Set<TreeItem>>
{
    private static final long serialVersionUID = 1L;
    private final String treePanelId;

    public TreeItemExpansionModel(String treePanelId) {
        this.treePanelId = treePanelId;
    }

    @Override
    protected Set<TreeItem> load() {
        return TreeItemExpansion.get(treePanelId);
    }

    @Override
    public boolean equals(Object obj) {
        if (obj instanceof TreeItemExpansionModel) {
            return ((TreeItemExpansionModel) obj).treePanelId.equals(treePanelId);
        }
        return false;
    }

    @Override
    public int hashCode() {
        return treePanelId.hashCode();
    }
}

错误如下:

Caused by: org.apache.wicket.core.util.objects.checker.CheckingObjectOutputStream$ObjectCheckException: Not detached model found!
A problem occurred while checking object with type: com.test.web.components.TreeItemProvider$TreeItemModel
Field hierarchy is:
   [class=com.test.web.admin.pages.HomePage, path=0]
    private java.lang.Object org.apache.wicket.MarkupContainer.children [class=[Ljava.lang.Object;]
      java.util.List com.test.web.components.WhistlePanel.selectionList[2] [class=com.test.web.NavPanel, path=0:navPanel]
        private java.lang.Object org.apache.wicket.MarkupContainer.children [class=org.apache.wicket.extensions.markup.html.repeater.tree.NestedTree, path=0:navPanel:tree]
          private java.lang.Object org.apache.wicket.MarkupContainer.children [class=org.apache.wicket.extensions.markup.html.repeater.tree.nested.Subtree, path=0:navPanel:tree:subtree]
            private java.lang.Object org.apache.wicket.MarkupContainer.children [class=org.apache.wicket.markup.repeater.RefreshingView, path=0:navPanel:tree:subtree:branches]
              private java.lang.Object org.apache.wicket.MarkupContainer.children [class=[Ljava.lang.Object;]
                private java.lang.Object org.apache.wicket.MarkupContainer.children[0] [class=org.apache.wicket.extensions.markup.html.repeater.tree.nested.BranchItem, path=0:navPanel:tree:subtree:branches:1]
                  java.lang.Object org.apache.wicket.Component.data [class=com.test.web.components.TreeItemProvider$TreeItemModel] <----- field that is causing the problem

提前致谢。

Answer 1

问题在于序列化检查器和模型生命周期管理的结合。

当您放置 LoadableDetachableModel 并初始化不可序列化的模型时，Wicket 检查器会抛出一个异常，表明您尝试序列化不可序列化的数据。这种行为是正确的。

发生这种情况的原因是

1. 身份验证不可序列化
2. 您调用 getDefaultModel().get() 来加载模型对象，即使它是延迟加载模型

请参阅NotDetachedModelChecker https://github.com/apache/wicket/blob/build/wicket-6.20.0/wicket-core/src/main/java/org/apache/wicket/core/util/objects/checker/NotDetachedModelChecker.java

建议修复:

I.使用AbstractReadOnlyModel代替LoadableDetachableModel

    public class CurrentUserModel extends AbstractReadOnlyModel<Authentication> {
       protected Authentication getObject() {
          return SecurityContextHolder.getContext().getAuthentication();
       }
    }

如果您确实需要保留该值(我认为这不是必需的，因为 Spring 身份验证上下文每次尝试都会返回相同的值)，请使用 AbstractReadOnlyModel 包装 LoadableDetachbleModel。

II. 分离模型:在将流程控制返回给 Wicket 之前调用authModel.detach();

protected void onInitialize() {
    IModel<Authentication> authModel = (IModel<Authentication>) getDefaultModel();
    final Authentication auth = authModel.getObject();

    if (auth != null && auth.isAuthenticated() && !(auth instanceof AnonymousAuthenticationToken))
    {
        Fragment fragment = new Fragment("frag", "loggedInFragment", this);
        Label status;
        fragment.add(status = new Label("status", "Logged in as "));
        fragment.add(new Label("userId", new PropertyModel<String>(authModel, "name")));
        add(fragment);
    }
    else
    {
        Fragment fragment = new Fragment("frag", "loggedOutFragment", this);
        fragment.add(new Label("status", "Logged out"));
        fragment.add(new ExternalLink("login", "/LoginPage", "Log In"));
        add(fragment);
    }
    authModel.detach();
    super.onInitialize();
}