[CAUSEWAY-2398] Rendering a StandaloneCollectionPage in Wicket throws Optional not serializable exception

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.0.0-M3
• Fix Version/s: 2.0.0-M4
• Assignee: Andi Huber
• Reporter: Daniel Keir Haywood
• Created: 09/Jul/20 05:37
• Updated: 17/Oct/20 05:51
• Resolved: 09/Jul/20 09:20

Description

For demo app, this occurs when Prototyping > Run Fixture Script.  See stacktrace

This seems to be just noise in the logs, but even so....

2020-07-09 06:36:13.588 ERROR 3524 --- [ageSavingThread] o.a.w.s.j.JavaSerializer                 : Error serializing object class org.apache.isis.viewer.wicket.ui.pages.standalonecollection.StandaloneCollectionPage [object=[Page class = org.apache.isis.viewer.wicket.ui.pages.standalonecollection.StandaloneCollectionPage, id = 4, 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: java.util.Optional
Field hierarchy is:
  4 [class=org.apache.isis.viewer.wicket.ui.pages.standalonecollection.StandaloneCollectionPage, path=4]
    private java.lang.Object org.apache.wicket.MarkupContainer.children [class=java.util.ArrayList]
      private java.lang.String org.apache.isis.viewer.wicket.ui.components.widgets.favicon.Favicon.contentType[write:6][write:7][write:8] [class=org.apache.wicket.markup.html.WebMarkupContainer, path=4:theme]
        private java.lang.Object org.apache.wicket.MarkupContainer.children [class=java.util.ArrayList]
          private org.apache.isis.viewer.wicket.ui.ComponentType org.apache.isis.viewer.wicket.ui.panels.PanelAbstract.componentType[write:12][write:13][write:20] [class=org.apache.isis.viewer.wicket.ui.components.actionprompt.ActionPromptModalWindow, path=4:theme:actionPromptModalWindow]
            private java.lang.Object org.apache.wicket.MarkupContainer.children [class=java.util.ArrayList]
              private java.lang.Object org.apache.wicket.MarkupContainer.children[write:3][write:5][write:8] [class=org.apache.isis.viewer.wicket.ui.components.actions.ActionParametersPanel, path=4:theme:actionPromptModalWindow:content]
                private java.lang.Object org.apache.wicket.MarkupContainer.children [class=java.util.ArrayList]
                  java.lang.Object org.apache.wicket.Component.data[write:8][write:4][write:7] [class=org.apache.isis.viewer.wicket.ui.components.actions.ActionParametersFormPanel, path=4:theme:actionPromptModalWindow:content:parameters]
                    private java.lang.Object org.apache.wicket.MarkupContainer.children [class=org.apache.isis.viewer.wicket.ui.components.actions.ActionParametersForm, path=4:theme:actionPromptModalWindow:content:parameters:inputForm]
                      private java.lang.Object org.apache.wicket.MarkupContainer.children [class=java.util.ArrayList]
                        private java.lang.Object org.apache.wicket.MarkupContainer.children[write:1] [class=org.apache.wicket.markup.repeater.RepeatingView, path=4:theme:actionPromptModalWindow:content:parameters:inputForm:parameters]
                          private java.lang.Object org.apache.wicket.MarkupContainer.children [class=java.util.ArrayList]
                            private java.lang.Object org.apache.wicket.MarkupContainer.children[write:1] [class=org.apache.wicket.markup.html.WebMarkupContainer, path=4:theme:actionPromptModalWindow:content:parameters:inputForm:parameters:1]
                              private java.lang.Object org.apache.wicket.MarkupContainer.children [class=org.apache.isis.viewer.wicket.ui.components.scalars.valuechoices.ValueChoicesSelect2Panel, path=4:theme:actionPromptModalWindow:content:parameters:inputForm:parameters:1:scalarNameAndValue]
                                java.lang.Object org.apache.wicket.Component.data [class=[Ljava.lang.Object;]
                                  java.lang.Object org.apache.wicket.Component.data[0] [class=org.apache.isis.viewer.wicket.model.models.ScalarParameterModel]
                                    private org.apache.isis.viewer.wicket.model.models.InlinePromptContext org.apache.isis.viewer.wicket.model.models.ScalarModel.inlinePromptContext [class=org.apache.isis.viewer.wicket.model.models.InlinePromptContext]
                                      private final org.apache.wicket.Component org.apache.isis.viewer.wicket.model.models.InlinePromptContext.scalarIfRegular [class=org.apache.isis.viewer.wicket.ui.components.widgets.bootstrap.FormGroup, path=4:theme:actionPromptModalWindow:content:parameters:inputForm:parameters:1:scalarNameAndValue:scalarTypeContainer:scalarIfRegular]
                                        private java.lang.Object org.apache.wicket.MarkupContainer.children [class=java.util.ArrayList]
                                          private java.lang.Object org.apache.wicket.MarkupContainer.children[write:1] [class=org.apache.isis.viewer.wicket.ui.components.widgets.select2.Select2ChoiceExt, path=4:theme:actionPromptModalWindow:content:parameters:inputForm:parameters:1:scalarNameAndValue:scalarTypeContainer:scalarIfRegular:scalarValue]
                                            private org.wicketstuff.select2.ChoiceProvider org.wicketstuff.select2.AbstractSelect2Choice.provider [class=org.apache.isis.viewer.wicket.ui.components.widgets.select2.providers.ObjectAdapterMementoProviderForValueChoices]
                                              private final org.apache.isis.core.commons.collections.Can org.apache.isis.viewer.wicket.ui.components.widgets.select2.providers.ObjectAdapterMementoProviderForValueChoices.choiceMementos [class=org.apache.isis.core.commons.collections.Can_Singleton]
                                                private final java.util.concurrent.atomic.AtomicReference org.apache.isis.core.commons.collections.Can_Singleton.singleton [class=java.util.concurrent.atomic.AtomicReference]
                                                  private volatile java.lang.Object java.util.concurrent.atomic.AtomicReference.value [class=java.util.Optional] <----- field that is causing the problem