ClassCastException when using a default empty array in CRD

[tomverelst]

Describe the bug

I have a CRD that has an array property in the spec that defaults to [].

foo:
  default: []
  items:
    properties:
      bar:
        type: string
    required:
      - bar
    type: object
type: array

I generate my Java classes using the io.fabric8:java-generator-maven-plugin:6.2.0 plugin (with generator-annotations). This results in the following generated code in my custom resource's Spec class:

    @com.fasterxml.jackson.annotation.JsonProperty("foo")
    @com.fasterxml.jackson.annotation.JsonSetter(nulls = com.fasterxml.jackson.annotation.Nulls.SKIP)
    private java.util.List<Foo> foo = io.fabric8.kubernetes.client.utils.Serialization.unmarshal("[]", java.util.List.class);;

When I attempt to initiate the spec class, it throws the following exception:

Caused by: java.lang.ClassCastException: class java.util.ArrayList cannot be cast to class java.util.Map (java.util.ArrayList and java.util.Map are in module java.base of loader 'bootstrap')
at io.fabric8.kubernetes.client.utils.Serialization.unmarshal(Serialization.java:237)

This error disappears when I remove the default: [] property from the array property.

Fabric8 Kubernetes Client version

6.2.0

Steps to reproduce

Run the following code:

io.fabric8.kubernetes.client.utils.Serialization.unmarshal("[]", java.util.List.class);

Expected behavior

Expect to have an ArrayList to be returned from the function call

Runtime

other (please specify in additional context)

Kubernetes API Server version

other (please specify in additional context)

Environment

macOS

Fabric8 Kubernetes Client Logs

java.lang.ClassCastException: class java.util.ArrayList cannot be cast to class java.util.Map (java.util.ArrayList and java.util.Map are in module java.base of loader 'bootstrap')
	at io.fabric8.kubernetes.client.utils.Serialization.unmarshal(Serialization.java:237)
	at io.fabric8.kubernetes.client.utils.Serialization.unmarshal(Serialization.java:351)
	at io.fabric8.kubernetes.client.utils.Serialization.unmarshal(Serialization.java:287)
	at io.fabric8.kubernetes.client.utils.Serialization.unmarshal(Serialization.java:272)

Additional context

No response

[shawkins]

Should be addressed by #4533

[tomverelst]

Should be addressed by #4533

Aha, cheers, did search for similar issues but did not find that one!

[andreaTP]

@tomverelst we already fixed this, can you try to use the snapshot release and see if that solves your issues?

[tomverelst]

Tested it and verified it works 👍 @andreaTP

Thanks all, closing this issue