We have an API endpoint that receives XML data from a 3rd party provider. The data itself is basical...

# announcements

[Lauritz Hilsøe]

We have an API endpoint that receives XML data from a 3rd party provider. The data itself is basically a list of elements, where each can be one of many different polymorphic types. They all share some attributes (say they all have a created_at="") and then some specific per element. Looked into using Jackson but it all seem very cumbersome, whats' the easiest way to parse this XML? An example could be

<?xml version="1.0" encoding="UTF-8">
<provider version="1.0">
  <update id="12313">
    <event name="hello" created_at="2019-12-14" />
    <event name="world" created_at="2019-12-16" />
    <country where="us" created_at="2019-15-16" />
  </update>
</provider>

Basically want to end up with a class containing ProviderUpdate(id: String, updates: List<Update>) where Update is either an interface, class, sealed class or something, that can either be Event or Country or etc

[Wesley Acheson]

I assume you've looked at stuff like this https://medium.com/@foxjstephen/how-to-actually-parse-xml-in-java-kotlin-221a9309e6e8 which doesn't seem too difficult to me.

[Lauritz Hilsøe]

@Wesley Acheson The XML example is too simple unfortunately, don't see any polymorphism

[Matteo Mirk]

Try having a look at the official docs: https://github.com/FasterXML/jackson-docs/wiki/JacksonPolymorphicDeserialization
The idea is to use @JsonTypeInfo and @JsonSubTypes to declare the expected types:
https://www.mkammerer.de/blog/jacksons-polymorphic-deserialization/
The annotations are the same for JSON, but you’ll need to use an XmlMapper instead of ObjectMapper