How to serialize class with sub classes

Vaadin 6 / 7 / 8
1

Hi!

I have 2 types of objects: boxes and links. simplifyed code:

[code]
public class ObjectData {

public static final int BOX = 1;

public static final int LINK = 2;

public int type;

public String id;

public ObjectData() {
}

public ObjectData(int type) {
    this.type = type;
}

public static class BoxData extends ObjectData {
    
    public String boxName;
    
    public BoxData() {
        super(BOX);
    }
    
}

public static class LinkData extends ObjectData {
    
    public String linkName;
    
    public LinkData() {
        super(LINK);
    }
    
}

}
[/code]shared state:

[code]
public class MySharedState extends AbstractComponentState {

public ObjectData object;

}
[/code]but on client when I try to cast ObjectData to correct BoxData I got:
…
Caused by: java.lang.ClassCastException
…

How to serialize objects like this? it is really common task

2

Get your basics right buddy :slight_smile: Implement serializable interface on both (LinkData & BoxData) or on ObjectData

This solves your problem.

Cheers,
Krishna.

3

it is simplifyed example yes. it implements Serializable in real code. and it is cause ClassCastException

4

Can you please share the stacktrace of the exception?

5

it is client side exception:

Exception caught: undefinedcom.google.gwt.event.shared.UmbrellaException: Exception caught: undefined
at Unknown.fillInStackTrace_0(com.nofilis.vaadin.DefaultWidgetSet-0.js@23)
at Unknown.fillInStackTrace(com.nofilis.vaadin.DefaultWidgetSet-0.js@3)
at Unknown.Throwable_1(com.nofilis.vaadin.DefaultWidgetSet-0.js@8)
at Unknown.Exception_1(com.nofilis.vaadin.DefaultWidgetSet-0.js@15)
at Unknown.RuntimeException_1(com.nofilis.vaadin.DefaultWidgetSet-0.js@15)
at Unknown.UmbrellaException(com.nofilis.vaadin.DefaultWidgetSet-0.js@22)
at Unknown.UmbrellaException_0(com.nofilis.vaadin.DefaultWidgetSet-0.js@21)
at Unknown.$fireEvent(com.nofilis.vaadin.DefaultWidgetSet-0.js@13)
at Unknown.$fireEvent_2(com.nofilis.vaadin.DefaultWidgetSet-0.js@66)
at Unknown.fireEvent_6(com.nofilis.vaadin.DefaultWidgetSet-0.js@3)
at Unknown.$sendStateChangeEvents(com.nofilis.vaadin.DefaultWidgetSet-0.js@28)
at Unknown.execute_24(com.nofilis.vaadin.DefaultWidgetSet-0.js@3)
at Unknown.runWhenDependenciesLoaded(com.nofilis.vaadin.DefaultWidgetSet-0.js@30)
at Unknown.$handleUIDLMessage(com.nofilis.vaadin.DefaultWidgetSet-0.js@3)
at Unknown.$handleReceivedJSONMessage(com.nofilis.vaadin.DefaultWidgetSet-0.js@3)
at Unknown.$handleWhenCSSLoaded(com.nofilis.vaadin.DefaultWidgetSet-0.js@45)
at Unknown.$handleJSONText(com.nofilis.vaadin.DefaultWidgetSet-0.js@5)
at Unknown.$start_0(com.nofilis.vaadin.DefaultWidgetSet-0.js@5)
at Unknown.execute_19(com.nofilis.vaadin.DefaultWidgetSet-0.js@3)
at Unknown.$executeScheduled(com.nofilis.vaadin.DefaultWidgetSet-0.js@30)
at Unknown.runScheduledTasks(com.nofilis.vaadin.DefaultWidgetSet-0.js@86)
at Unknown.$flushPostEventPumpCommands(com.nofilis.vaadin.DefaultWidgetSet-0.js@47)
at Unknown.execute_2(com.nofilis.vaadin.DefaultWidgetSet-0.js@35)
at Unknown.execute_1(com.nofilis.vaadin.DefaultWidgetSet-0.js@14)
at Unknown.apply_0(com.nofilis.vaadin.DefaultWidgetSet-0.js@23)
at Unknown.entry0(com.nofilis.vaadin.DefaultWidgetSet-0.js@16)
at Unknown.eval(com.nofilis.vaadin.DefaultWidgetSet-0.js@14)
at Unknown.eval(com.nofilis.vaadin.DefaultWidgetSet-0.js@32)
at Unknown.eval(com.nofilis.vaadin.DefaultWidgetSet-0.js@5)
Caused by: java.lang.ClassCastException
at Unknown.fillInStackTrace_0(com.nofilis.vaadin.DefaultWidgetSet-0.js@23)
at Unknown.fillInStackTrace(com.nofilis.vaadin.DefaultWidgetSet-0.js@3)
at Unknown.Throwable(com.nofilis.vaadin.DefaultWidgetSet-0.js@8)
at Unknown.Exception(com.nofilis.vaadin.DefaultWidgetSet-0.js@13)
at Unknown.RuntimeException(com.nofilis.vaadin.DefaultWidgetSet-0.js@13)
at Unknown.ClassCastException(com.nofilis.vaadin.DefaultWidgetSet-0.js@20)
at Unknown.dynamicCast(com.nofilis.vaadin.DefaultWidgetSet-0.js@11)
at Unknown.onStateChanged_6(com.nofilis.vaadin.DefaultWidgetSet-0.js@9)
at Unknown.$dispatch_32(com.nofilis.vaadin.DefaultWidgetSet-0.js@12)
at Unknown.dispatch_33(com.nofilis.vaadin.DefaultWidgetSet-0.js@22)
at Unknown.dispatch(com.nofilis.vaadin.DefaultWidgetSet-0.js@8)
at Unknown.dispatchEvent_1(com.nofilis.vaadin.DefaultWidgetSet-0.js@11)
at Unknown.$doFire(com.nofilis.vaadin.DefaultWidgetSet-0.js@9)
at Unknown.$fireEvent_0(com.nofilis.vaadin.DefaultWidgetSet-0.js@3)
at Unknown.$fireEvent(com.nofilis.vaadin.DefaultWidgetSet-0.js@29)
at Unknown.$fireEvent_2(com.nofilis.vaadin.DefaultWidgetSet-0.js@66)
at Unknown.fireEvent_6(com.nofilis.vaadin.DefaultWidgetSet-0.js@3)
at Unknown.$sendStateChangeEvents(com.nofilis.vaadin.DefaultWidgetSet-0.js@28)
at Unknown.execute_24(com.nofilis.vaadin.DefaultWidgetSet-0.js@3)
at Unknown.runWhenDependenciesLoaded(com.nofilis.vaadin.DefaultWidgetSet-0.js@30)
at Unknown.$handleUIDLMessage(com.nofilis.vaadin.DefaultWidgetSet-0.js@3)
at Unknown.$handleReceivedJSONMessage(com.nofilis.vaadin.DefaultWidgetSet-0.js@3)
at Unknown.$handleWhenCSSLoaded(com.nofilis.vaadin.DefaultWidgetSet-0.js@45)
at Unknown.$handleJSONText(com.nofilis.vaadin.DefaultWidgetSet-0.js@5)
at Unknown.$start_0(com.nofilis.vaadin.DefaultWidgetSet-0.js@5)
at Unknown.execute_19(com.nofilis.vaadin.DefaultWidgetSet-0.js@3)
at Unknown.$executeScheduled(com.nofilis.vaadin.DefaultWidgetSet-0.js@30)
at Unknown.runScheduledTasks(com.nofilis.vaadin.DefaultWidgetSet-0.js@86)
at Unknown.$flushPostEventPumpCommands(com.nofilis.vaadin.DefaultWidgetSet-0.js@47)
at Unknown.execute_2(com.nofilis.vaadin.DefaultWidgetSet-0.js@35)
at Unknown.execute_1(com.nofilis.vaadin.DefaultWidgetSet-0.js@14)
at Unknown.apply_0(com.nofilis.vaadin.DefaultWidgetSet-0.js@23)
at Unknown.entry0(com.nofilis.vaadin.DefaultWidgetSet-0.js@16)
at Unknown.eval(com.nofilis.vaadin.DefaultWidgetSet-0.js@14)
at Unknown.eval(com.nofilis.vaadin.DefaultWidgetSet-0.js@32)
at Unknown.eval(com.nofilis.vaadin.DefaultWidgetSet-0.js@5)

6

This is something you are getting on the client side, on which I have very minimal knowledge. Anyway kindly check if you have compiled & packaged the widgetset properly.

I’m sorry buddy :frowning:

7

NP. Thanks)