If you call SpecificAvroSerde configure multiple times the result is that the value used in the first call is used, not the value used in the last call. This is not documented and is surprising.

For example if you have a class that instantiates a SERDE with typical values, but then have a test case that attempts to use the "mock://testing" url for the AbstractKafkaSchemaSerDeConfig.SCHEMA_REGISTRY_URL_CONFIG property the test will not use the mock schema registry as expected.

Work around is to re-organize your code to ensure configure is never called more than once. Requested fix is either to document this behavior or update the code to allow configure to accept changes.