Question

我有一个带有标签的主页（BasePage），一切正常，我的代码功能没有任何问题。但这个例外让我烦恼，我想摆脱它。我看了这个

Error serializing object class - when running Wicket and GAE

和这个

Wicket: how to get rid of WicketNotSerializableException?

但我无法解决我的问题。任何人都可以帮助我吗？

public class BasePage extends WebPage {
    public static final String PATH = "base";

    public BasePage() {
        final List tabs = new ArrayList<>();

        //add Search Item Tab
        tabs.add(new AbstractTab(new Model<>("Search Item")) {
            @Override
            public WebMarkupContainer getPanel(String s) {
                return new SearchItem(s);
            }
        });

        //add Search Domain Tab
        tabs.add(new AbstractTab(new Model<>("Search Domain")) {
            @Override
            public WebMarkupContainer getPanel(String s) {
                return new SearchDomain(s);
            }
        });

        AjaxTabbedPanel ajaxTabbedPanel = new AjaxTabbedPanel("tabs", tabs);

        add(new AjaxTabbedPanel("tabs", tabs));
    }
}

堆栈跟踪：

2015-08-28 11:39:48,456 [http-bio-8080-exec-12] ERROR org.apache.wicket.serialize.java.JavaSerializer - Error serializing object class com.ui.homepage.BasePage [object=[Page class = com.ui.homepage.BasePage, id = 0, render count = 1]]
org.apache.wicket.core.util.objects.checker.CheckingObjectOutputStream$ObjectCheckException: The object type is not Serializable!
A problem occurred while checking object with type: com.persistence.RequestEntityDAOExtra
Field hierarchy is:
  0 [class=com.ui.homepage.BasePage, path=0]
    private java.lang.Object org.apache.wicket.MarkupContainer.children [class=org.apache.wicket.extensions.ajax.markup.html.tabs.AjaxTabbedPanel, path=0:tabs]
      private java.lang.Object org.apache.wicket.MarkupContainer.children [class=[Ljava.lang.Object;]
        private org.apache.wicket.markup.html.link.PopupSettings org.apache.wicket.markup.html.link.Link.popupSettings[1] [class=com.searchpages.SearchItem, path=0:tabs:panel]
          private java.lang.Object org.apache.wicket.MarkupContainer.children [class=[Ljava.lang.Object;]
            private java.lang.Object org.apache.wicket.MarkupContainer.children[1] [class=org.apache.wicket.markup.html.form.Form, path=0:tabs:panel:searchForm]
              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.markup.html.WebMarkupContainer, path=0:tabs:panel:searchForm:searchInput]
                  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.ajax.markup.html.autocomplete.AutoCompleteTextField, path=0:tabs:panel:searchForm:searchInput:callerId]
                      final com.persistence.RequestEntityDAOExtra com.ui.searchpages.SearchItem$1.val$requestEntityDAOExtra [class=com.persistence.RequestEntityDAOExtra] <----- field that is causing the problem

更新：我发现了问题，但我无法理解它为什么会起作用

在：

final RequestEntityDAOExtra requestEntityDAOExtra =
        ((MyApp) getApplication()).getRequestEntityDAOExtra();

//callerId input
final AutoCompleteTextField<String> callerInput = new AutoCompleteTextField<String>("callerId", new Model<String>(),
        autoCompleteSettings) {
    @Override
    protected Iterator getChoices(String callerId) {
        return requestEntityDAOExtra.getEntitiesByCallerId(callerId).iterator();
    }
};

后：

final AutoCompleteTextField<String> callerInput = new AutoCompleteTextField<String>("callerId", new Model<String>(),
        autoCompleteSettings) {
    @Override
    protected Iterator getChoices(String callerId) {
        final RequestEntityDAOExtra requestEntityDAOExtra =
                ((MyApp) getApplication()).getRequestEntityDAOExtra();
        return requestEntityDAOExtra.getEntitiesByCallerId(callerId).iterator();
    }
};

如果我在方法中声明我的dao对象，则异常不再存在。但为什么呢？

Answer 1

好像RequestEntityDAOExtra似乎不是Serializable。我不能真正说出原因，或者它应该是Serializable因为它在很大程度上取决于你的申请。

在你的第一个案例中你宣告：

final RequestEntityDAOExtra requestEntityDAOExtra =
    ((MyApp) getApplication()).getRequestEntityDAOExtra();

在序列化期间，这将被视为与任何成员变量相同，因为每当执行匿名内部类时都需要恢复它。我的建议是在Wicket上下文中工作时将变量声明为final时要非常小心。对于我的项目，我只允许将IModel的实现声明为final（加上任何Wicket组件）。

您的第二种方法有效，因为RequestEntityDAOExtra不会使用Panel序列化，而是每次从Application新请求。

JavaSerializer - 序列化对象时出错 - ＆gt;便门

1 个答案: