Dealing with different JSON value types in a Map

[Everett Toews]

We have a situation uncovered by this issue [1] where the JSON response has 
different value types for String keys in a Map.

For example,

{
  "images": [
    {
      "id": "cd9d57a9-0978-45f3-9cbc-edb99347be6b",
      "metadata": {
        "block_device_mapping": [
          {
            "snapshot_id": "a900a56c-61b7-4438-9150-76312fa1aa10",
            "destination_type": "volume",
            "delete_on_termination": null
          }
        ],
        "checksum": "32c08d302f9206668030d47789b77858”,
        ”some_key”: ”some_value”,
      }
    },
    ….
}

This is handled by deserialization of this field in the Image domain object 
[2]. Because it’s a Map<String, String> it blows up with an exception when it 
hits the block_device_mapping, which is an array.

IllegalStateException: Expected a string but was BEGIN_ARRAY

Doing something like Map<String, Object> isn’t a great option as it forces the 
caller to constantly check for the type. 99% of the time it’s going to be 
Map<String, String> so it pains me to consider complicating the client code for 
this corner case.

Any thoughts on how to gracefully handle this situation?

Thanks,
Everett

[1] https://issues.apache.org/jira/browse/JCLOUDS-655
[2] 
https://github.com/jclouds/jclouds/blob/master/apis%2Fopenstack-nova%2Fsrc%2Fmain%2Fjava%2Forg%2Fjclouds%2Fopenstack%2Fnova%2Fv2_0%2Fdomain%2FImage.java#L207