Dangling name error when trying to update extensionAttributes on a device

[ian-mcmanus-polarmoment]

Describe the bug

I am trying to update one of the extensionAttribute values within the additionalData of a device, but getting the following error:

java.lang.IllegalStateException: Dangling name: extensionAttributes

I'm following the example 2 from here - https://learn.microsoft.com/en-us/graph/api/device-update?view=graph-rest-1.0&tabs=java - although the example isn't fully complete for updating the extensionAttributes. There seems to be a model within the SDK to use for OnPremiseExtensionAttributes but not for extensionAttributes.

If I get additonalData using device.getAdditionalData() it contains the the list of the 15 extensionAttributes that can be used.

Expected behavior

Expect the extensionAttribute to update successfully, which works if updating via HTTP for example.

How to reproduce

Device newDevice = new Device();
		
Map<String,Object> additionalData = new HashMap<>();

Map<String,String> attribute = new HashMap<>();
attribute.put("extensionAttribute1", "123456");

additionalData.put("extensionAttributes", attribute);

newDevice.setAdditionalData(additionalData);

try {
	client.devices().byDeviceId(deviceId).patch(newDevice);
} catch(Exception e) {
	//handle exception
}

SDK Version

6.16.0

Latest version known to work for scenario above?

No response

Known Workarounds

No response

Debug output

Click to expand log

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### Configuration

_No response_

### Other information

_No response_

[andrueastman]

Thanks for raising this @iantmc87

I believe the issue here is that the serializer does not handle maps when present in the addtionalData. To do this, we would need to add a case in this function to handle maps so that the seriliazer does not write the key and nothing is written for its value.

https://github.com/microsoft/kiota-java/blob/5d6671eee75d77e415248d40f1113cb63886fbdd/components/serialization/json/src/main/java/com/microsoft/kiota/serialization/JsonSerializationWriter.java#L494C54-L494C76