Json Ignore Property on JsonSubTypes - json

Question

I have a Scala case class that represents my JSON as below:
class MyJSON(x: Int, typeA: TypeA, typeB: TypeB)
#JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY, property = "type")
#JsonSubTypes(Array(
new Type(value = classOf[ClassA], name = "ClassA"),
new Type(value = classOf[ClassB], name = "ClassB")))
trait TypeA {
...
...
}
In my ClassA, I have certain fields that are deserialized from the JSON. But I also want that if there are certain fields that are not part of my Class objects, I want them to be ignored. What I did was I used the #JsonIgnoreProperties(ignoreUnknown=true) annotation on the MyJSON class as below:
#JsonIgnoreProperties(ignoreUnknown=true)
class MyJSON(x: Int, typeA: TypeA, typeB: TypeB)
It failed when my input JSON had some unknown fields. But when I moved this annotation to one of my Class (say ClassA) in my case, it was ignored. The problem is that I do not want to add this ignore properties annotation to all my classes, but rather I add it just to the top and want that propagated to all the types.

Answer 1

Try this
objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);

Answer 2

I found a much elegant solution to the problem. I used Jackson MixIn mechanism to actually add the additional annotations to my target types during runtime. Here is what I did:
#JsonIgnoreProperties({ Array("field1", "field2") })
abstract class MixInAnnotations{}
In my JSONMarshaller class where I create the ObjectMapper, I do the following:
val mapper = new ObjectMapper()
mapper.registerModule(new MyApplicationModule)
The MyApplicationModule now looks like:
public class MyApplicationModule extends com.fasterxml.jackson.databind.module.SimpleModule {
public MyApplicationModule() {
super(MyApplicationModule.class.getSimpleName());
// Add the corresponding MixIn Annotations to ignore the JSON properties
setMixInAnnotation(MyTargetClass1.class, MixInAnnotations.class);
setMixInAnnotation(MyTargetTrait.class, MixInAnnotations.class);
}
}
I call the setter methods to add the MixInAnnotations to my target classes. The target classes here could also be a trait that has the JsonSubTypes Annotation. So effectively, I'm not polluting all my types with the #JsonIgnoreProperties annotation.