Check out this article describing how to use the features of the jackson objectMapper to accomplish this.

https://github.com/FasterXML/jackson-dataformat-xml/issues/21

For me adding the following solved this issue

jsonMapper.configure(Feature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);

Check out this article describing how to use the features of the jackson objectMapper to accomplish this.

https://github.com/FasterXML/jackson-dataformat-xml/issues/21

For me adding the following solved this issue

jsonMapper.configure(DeserializationFeature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);